MXPA00001088A - Modified polylactide compositions, water-responsive, biodegradable films and fibers comprising polylactide and poly(vinyl alcohol) and methods for making the same - Google Patents

Abstract

The present invention discloses water-responsive films and fibers. More particularly, the present invention includes films and fibers comprising blends of a polyvinyl alcohol and a polylactide and methods of making such films and fibers. In a preferred embodiment, the invention includes films and fibers comprising a blend of polyvinyl alcohol and modified polylactide and a method of modifying a polylactide. In a preferred embodiment, the present invention includes a hydrolytically modified, biodegradable polymer and a method of hydrolytically modifying a biodegradable polymer. In a preferred embodiment, the invention is a method of grafting polar groups onto polylactides and modified polylatide compositions produced by the method. The modified compositions, blends, films and fibers are useful as components in flushableand degradable articles.

Description

MODIFIED POLYCARACTIC COMPOSITIONS, MOVIES BIODEGRADABLES THAT RESPOND TO WATER AND FIBERS THAT UNDERSTAND POLYLACTIC AND POLY (VINYL ALCOHOL) AND METHODS TO MAKE THE SAME FIELD OF THE INVENTION The present invention relates to hydrolytically modified biodegradable polymer and methods for hydrolytically modifying biodegradable polymers. More particularly, the present invention relates to modified polylactide compositions and methods for modifying polylactides. In a preferred embodiment, the invention relates to a method for grafting polar groups on polylactides, to grafted polylactide compositions and films and to fibers comprising the same. The present invention also relates to biodegradable films which respond to water and to fibers comprising a polylactide and polyvinyl alcohol and to a method for varying the water response of such fibers and films.

BACKGROUND OF THE INVENTION Even though the amount of plastics used in a variety of consumer items, packaging and medical items has not significantly increased over the last P Twenty years, the common perception is that more and more non-degradable plastic are filling the limited space of land d filled. Despite this perceived disadvantage, plastic continues to be used in the manufacture of consumer goods, packaging and medical articles because plastics offer many advantages over traditional materials: wood, glass, paper, and metal. The advantages of using plastics, more precisely polymers, include manufacturing time and decreased costs, improved mechanical chemical properties, and decreased weight and decreased transportation costs. The improved chemical resistance properties of most plastics is what results in non-degradability.

Disposal of waste materials, including food waste, packaging materials and medical waste, in typical landfills provides a relatively stable environment in which none of these materials is seen to decompose at a time. appreciable. Alternate waste disposal options have been increasingly discussed and used to divert some of the waste from the burial. Examples of these alternate disposal options include municipal solid waste composting, anaerobic digestion, enzymatic digestion, sewage water sewage treatment. p Many controversies are associated with the waste of medical waste. Both government agencies and the members of the private sector have directed in an increased way, deep scrutiny and funds to this matter. Admittedly, 5 concerns about the fate of materials contaminated with infectious substances are valid and appropriate measures must be taken to ensure the health of the carers and the general public.

Currently medical waste can be categorized as either reusable or disposable. The categorization as to which certain waste material is reusable disposable is determined in a customary manner according to the material from which the article was constructed and the purpose for which it is intended. which article was used.

After use, medical items are cleaned and sterilized under astringent conditions to ensure disinfection. In comparison, medical articles disposable are only used once. Even then, the disposal procedures are not direct, but this often involves several steps to safeguard against potential hazards. Typically, after the use of the disposable medical items can be disinfected 25 sterilized, adding a significant cost before discarding in a waste incinerator or a specially designated landfill. As a result, the cost of disposing for contaminated single-use items is very high.

Despite the high cost of waste, single medical use items are desirable because they ensure cleanliness and non-contaminated equipment. Many times in the medical context, sterilization procedures carried out improperly can result in detrimental effects such as the transmission of infectious agents from one patient to another. Inappropriate sterilization can also be disastrous in a laboratory, where, for example, contaminated equipment can ruin experiments that result in tremendous time and money costs.

Currently, disposable medical fabrics are generally composed of thermoplastic fibers such as polyethylene, polypropylene, polyesters, polyamides and acrylics. These fabrics may also include thermosetting fiber blends such as polyamides, polyaryimides, cellulosics. The fabrics are typically from 10 to 100 grams per square yard by weight and can be woven, woven or otherwise formed by methods well known to those skilled in the textile arts while non-woven fabrics can be thermally bonded, hydroentangled, placed in Wet or perforated co needles. The films can be formed by blown extrusion setting or by setting the solution. Once used, these fabrics and films are difficult and expensive to discard and are not degradable.

The use of polymers for various disposable articles is widespread and well known in the art. In fact, the heaviest use of polymers in the form of films and fibers occurs in the packaging and in the industries of disposable articles. Films used in the packaging industry include those used in the packaging of food and non-food items, merchandise bags, and garbage bags. In the disposable article industry, general uses of polymers occur in the construction of diapers, personal hygiene items, surgical covers and hospital suits, instrument pads, bandages, and protective covers for various items.

In view of the inadequate disposal sites of landfill space depletion, there is a need for polymers which respond to water. Currently, even when polymers such as polyethylene, polypropylene, polyethylene terephthalate, nylon, and polystyrene, polyvinyl chloride and polyvinylidene chloride are popular for their superior extrusion and film and fiber-making properties, these polymers They do not respond to water. In addition, these polymers are not generally compostable which is undesirable from an environmental perspective.

Polymers and polymer blends have been developed which are generally considered to respond to water. These are polymers which are said to have adequate properties to allow them to break when exposed to conditions which lead to composting. Examples of such polymers that respond to water in an addable form include those made from biopolymers of polyvinyl alcohol starch.

Even though materials made from these polymers have been used in films and articles containing fibers, many problems have been encountered with their use. Frequently, polymers and articles made from these polymers are not completely compostable or do not completely respond to water. In addition, some polymers that respond to water may also be unduly sensitive to water, either by limiting the use of the polymer or by requiring some type of surface treatment for the polymer, often by rendering the polymer unresponsive to water. Other polymer are undesirable because they have inadequate heat resistance for wide use.

Personal care products, such as diapers, sanitary napkins, adult incontinence garments, and the like, are generally constructed of a number of different components and materials. Such items usually have some component, usually the backing layer, constructed of a water barrier or liquid repellent polymer material. The commonly used water-sweeping material includes polymer materials such as polyethylene films or copolymers of ethylene and other polar and non-polar monomers. The purpose of the water barrier layer is to minimize or avoid the absorbed liquid which may, during use, exude from the absorbent component and foul the wearer or adjacent clothing. The water barrier layer also has the advantage of allowing a greater utilization of the absorbent capacity of the product.

Even when such products are relatively cheap, sanitary and easy to use, the disposal of soiled products is not without its problems. Typically, soiled products are discarded in a solid waste receptacle. This increases the accumulation of waste from solid waste and increases costs and presents health risks for people who may come in contact with the soiled product. An alternative waste idea would be the use of private residential septic systems and municipal sewage treatment by discarding co-discharge of water from the product soiled in a toilet. The products suitable for disposal in sewer systems are called "disposable with water discharge". Even though waste with water discharge from such items would be convenient, prior art materials do not disintegrate in water. This tends to clog the toilets and sewer pipes, often requiring a visit from a plumber. In the municipal sewage treatment plant, the liquid repellent material can interrupt operations by clogging the grids causing sewage disposal problems. It is therefore necessary, even when undesirable, to separate the barrier film material from the absorbent article before disposal with water.

In addition to the article itself, typically the packaging in which the disposable article is distributed is also made of a water resistant material specifically from a water sweep. Water resistance is necessary to avoid degradation of the packaging due to environmental conditions and to protect the disposable items placed there. Even when this package can be safely stored with other waste for commercial disposal, and especially in the case of individual packages of the products, it would be more convenient to dispose of the packages in the toilet with the discarded article discarded. However, where such a package is composed of a water resistant material, the aforementioned problems persist.

The use of lactic acid and lactide to make a stable polymer in water is known in the medical industry. Such polymers have been used in the past to make water-stable sutures, clamps, bone plates, biologically active controlled release devices. The process developed for the manufacture of such polymer used in the medical industry has incorporated techniques which respond to the need for a high purity biocompatibility in the final product. These processes, however, are typically designed to produce small volumes of products with a high cash value, with less emphasis on manufacturing cost and performance.

It is generally known that lactide or poly (lactide) polymers are unstable. However, the consequence of this instability has several aspects. One aspect is biodegradation or other forms of degradation that occur when lactic acid polymers, or articles made of lactide polymer, are discarded or composted after their useful life is completed. Another aspect of such instability is the degradation of the lactide polymers during processing at elevated temperatures such as, for example, during the melting process by the end-user purchasers of the polymer resins.

In the medical area there is a predominant need for polymers which are highly stable and therefore desirable for use in medical devices. Such demand has historically been prevalent in the low-volume, high-value medical specialty market, but now also and equally prevalent in the high volume and low value medical market.

As described in U.S. Patent No. 5,472,518, compositions composed of multilayer polymer films are known in the art. The usefulness of such structures lies in the manipulation of physical properties in order to increase the stability or life time during the use of such a structure. For example, U.S. Patent No. 4,826,493 describes the use of a thin layer of hydroxybutyrate polymer as a component of a multilayer structure to be used as a barrier film in diapers and ostomy bags.

Another example of the use of multiple layer films has been found in U.S. Patent No. 4,620,999 which describes the use of a water soluble film coated with or laminated to a water insoluble film as a disposable bag. . The patent describes a package for the waste of the body which is stable said body waste during use, but which can be made to degrade in the toilet, at an adequate rate to enter a sewer system without blockage, mediant adding a caustic substance to achieve a pH level of at least 12. Such structures usually consist of a layer of polyvinyl alcohol film coated with polyhydroxybutyrate.

A similar excretion treatment bag which allows disposal in a suitable toilet or container is described in Japanese Patent 61-42127. The disclosed bag is composed of an inner layer of a water-dispersible, water-resistant resin, such as polylactide, and an outer cap of polyvinyl alcohol. As described in this patent, there are many examples of multi-layer films that are used in disposable objects. Most of these examples consist of films or fibers which are composed of outer layers of an environmentally degradable polymer and an inner layer of a polymer that responds to water. Typically, the outer layers are composed of polycaprolactone or ethylene vinyl acetate and the inner layer is composed of polyvinyl alcohol. These examples, however, are all limited to compositions consisting of multiple layers of different polymers, and do not cover the actual mixture of the different polymers.

A family of patents, EP 241178, Japanese 62-223112 and U.S. Patent No. 4,933,182 disclose a controlled release composition for treating periodontal disease. These controlled release compositions are composed of a therapeutically effective agent in a carrier consisting of polymer particles of limited water solubility dispersed in a water soluble polymer. Although the carrier of these inventions includes the use of more than one polymer, the described carrier is not mixed because the water-soluble polymer of limited solubility is incorporated into the water-soluble polymer as particles varying in average particle size of the polymer. from 1 to 500 microns.

The use of polymers for use in articles responsive to water is described in U.S. Patent No. 5,508,101, U.S. Patent No. 5,567,510, and U.S. Patent No. 5,567,510. America No. 5,472,518. This patent group describes a series of water-responsive compositions comprising a hydrolytically degradable polymer and a water-soluble polymer. The compositions of this group, however, consist of articles constructed of polymers which are first formed into fibers or films and are then combined. As such, the compositions are currently mini-layers of the individual polymer films or fibers. Therefore, when the fibers and films of the polymers of such compositions are considered to be in close proximity to each other, they are not real mixtures. The dispersion of one polymer into another in these compositions is not seen as approximately uniform since the individual polymers are essentially separate fibers or separate films.

The patent of the United States of America No. 5,525,671 issued to Ebato et al. Describes a method for making a linear lactic acid copolymer of a lactide monomer and a monomer containing a hydroxyl group. The polymer described by Ebato is a linear lactic copolymer produced by reacting two monomers to form a linear polymer with a block or random structure. Ebato does not describe grafted copolymers.

The polymer blend compositions for making fibers and films that are optimally combined are desirable because they are highly stable. The optimum combination of polymers means that the polymers are closely connected as possible without the requirement of copolymerization. Even when the mixed polymer compositions are known, the improved polymer blends where the fibers and films are most closely connected are desirable since the resulting composition is then more stable, foldable and versatile.

In addition to the need for polymer compositions which are highly stable and therefore suitable for regular use in most disposable articles, there is a simultaneous need for such polymer compositions to respond to water. What is required, therefore, is a material that responds to water that can be used for the manufacture of disposable articles. Such material should be versatile to produce and process cheaply. The material must be sufficiently stable for the intended use but degraded under predetermined conditions.

In addition, there is an increased emphasis on environmentally safe materials and environmentally safe coating. These environmentally safe coatings reduce the use of solvent-based coatings and rely, to an ever increasing extent, on polar coatings, such as water-based materials. The utility of the grafted copolymers of this invention includes, but is not limited to materials that have a higher affinity for the polar coating.

Therefore, it is an object of this invention to make a hydrolytically modified biodegradable polymer, films and fibers containing the same.

Another object of this invention is to make thermally processable polymers, blends, films, fiber articles.

Another object of this invention is to make commercially viable polymers, films and fiber commercially viable.

Another object of this invention is to make thermally processable biodegradable polymers, blends, films and fibers, which are more compatible with polar polymers and other polar substrates.

Another object of the invention is to make a hydrolytically modified biodegradable polymer useful for making biodegradable and disposable polymer compositions with water discharge and mixtures, films, fibers and articles containing them.

Another object of this invention is to make a hydrolytically modified biodegradable polymer useful for making mixtures, films and fibers with improved mechanical and physical properties.

Another object of this invention is to make modified polylactide which has improved compatibility in blends with polar polymers.

Another object of the invention is to make improved blends comprising polylactides.

Another object of the invention is to make a mixture of processable biodegradable polymer, films and fibers which are more compatible with polar polymers and other polar substrates.

Another object of this invention is to make polymers, blends, films, fibers and articles biodegradable and responsive to water.

Another object of this invention is to make polymers, blends, films and biodegradable fibers that respond to water with improved physical and mechanical properties.

Another object is to develop a method for making mixtures, films, fibers and articles that respond to water, which can be made to be dispersible in water weak in water or stable in water.

SYNTHESIS OF THE INVENTION The present invention describes biodegradable, water-responsive blends, films and fibers and contains a polyvinyl alcohol and a polylactide. The mixtures which respond to water and the films and the fibers made therefrom have a wide range of response, ranging from dispersible in water to water-degradable and stable in water. The present invention also describes a method for controlling the response to water of the mixtures, of the films and of the fibers by varying the amount of the polyvinyl alcohol from about 1 to about 99% of the mixture and varying the amount of the polyvinyl alcohol. polylactide from about 1 to about 99% by weight of the mixture. The response ranges of the composition for each type of response to agu are described.

In a preferred embodiment, the invention includes modified polylactide compositions comprising a polylactide grafted with polar monomers. The present invention discloses polylactide compositions grafted with 2-hydroxyethyl methacrylate or poly (ethylene glycol) methacrylate, as well as a reactive extrusion process to make the modified polylactide compositions.

Polylactides are biodegradable polymers which are commercially available and thermally processable. By grafting the polar monomers onto a polylactide, the resulting modified polylactide is more compatible with polar polymers and other polar substrates. For the development of a disposable material with water discharge, the modified polylactide compositions of the present invention have increased compatibility with water-soluble polymers, such as polyvinyl alcohol and polyethylene oxide, as compared to modified polylactide n. The compatibility of the modified polylactide compositions with a polar material can be controlled by the selection of the monomer and the level of grafting. The compatibility of the mixtures with the modified polylactide compositions leads to improved processing and improved physical properties of the resulting mixture.

The compositions that respond to the water described in the present invention have the unique advantage of being biodegradable so that the compositions, and films, fibers and articles made from these compositions, can be degraded into aeration tanks by aerobic degradation and anaerobic digesters by anaerobic degradation. e wastewater treatment plants. Therefore, articles made from the compositions of the present invention will significantly increase the volume of the accumulated sludge in the waste water treatment plants.

The fibers of the present invention are useful as components of disposable person care products, such as diaper liners, nonwoven fabrics bonded with yarn for clothing type outer covers, and the like. The films of the present invention are useful as components of disposable personal care products, such as separator films for adult and female care products, for outer diaper covers, and the like.

BRIEF DESCRIPTION OF THE FIGURES Figure 1 is a diagram of the viscosity e against the cut rate of a grafted polylactide according to the present invention and an ungrafted polylactide, demonstrating the decrease in viscosity of a grafted polylactide against an ungrafted polylactide.

DETAILED DESCRIPTION OF THE INVENTION Polylactide (PLA) resins are produced by different synthetic methods, such as lactide ring opening polymerization or condensation and direct polymerization of lactic acid. Both polymerization methods are useful for the present invention. Polylactide resins are a biodegradable polymer that has the chemical structure: [-CH (CH3) C02-] n.

The polylactide compositions described in the following examples are made by using a reactive class polylactide d purchased from Aldrich Chemical Company of Milwaukee Wisconsin (Catalog Number Aldrich 42,232-6). The polylactide purchased from Aldrich Chemical Company is biodegradable and has a number average molecular weight of about 60.00 grams per mole and a weight average molecular weight of about 144,000 grams per mole. This polylactide is made primarily of L-isomer and has a glass transition temperature (Tg) of 60 ° C. Any polylactide can be selected for use in the present invention and the molecular weights of the polylactide can vary depending on the desired properties and use.

Ethylenically unsaturated monomers which contain a polar functional group, such as hydroxyl, carboxyl, amino, carbonyl, halo, thiol, sulphonic, sulfonate, etc., are suitable for the present invention. Ethylenically unsaturated and preferred monomers containing a polar functional group include 2-hydroxyethyl methacrylate (hereinafter referred to as HEMA) and poly (ethylene glycol) methacrylate (hereinafter referred to as PEG-MA). S expects that a wide range of polar vinyl monomers will be acceptable to impart the same effects as 2-hydroxyethyl methacrylate and that poly (ethylene glycol) methacrylate to the polylactide resin will be effective monomers for grafting. The grafted polylactide can contain from about 1 20% by weight of grafted polar monomers, polymeric oligomers. Preferably, the grafted polylactide contains d from about 2.5 to 20% by weight of grafted polaro monomers, oligomers or polymers and more preferably 2.5-10% by weight of grafted polar monomers, oligomers, polymers.

Both the 2-hydroxyethyl methacrylate (Number d Catalog Aldrich 12,863-8) and the poly (ethylene glycol) methacrylate (Catalog Number Aldrich 40,954-5) used in the examples are supplied by Aldrich Chemical Company. The poly (ethylene glycol) methacrylate purchased from Aldrich Chemica Company is poly (ethylene glycol) ethyl ether methacrylate having a number average molecular weight of about 246 grams per mole.

The method for making the grafted polylactide compositions has been demonstrated by a reactive extrusion process. The grafting reaction can also be carried out in other reaction devices provided that the necessary mixing of polylactide and 2-hydroxyethyl methacrylate and / or poly (ethylene glycol) methacrylate, and any other reactive ingredients, is achieved and sufficient energy is provided. to carry out the grafting reactions.

Other reactive ingredients which may be added to the compositions of this invention include, but are not limited to initiators such as LUPERSOL 10. (hereinafter referred to as L101), a liquid organic peroxide available from Elf Atochem North America, Inc., d Philadelphia, Pennsylvania. Libr radical initiators useful in the practice of this invention include but are not limited to acyl peroxides such as benzoyl peroxide; dialkyl, diaryl, or aralkyl peroxides, such as di-t-butyl peroxide; dicumyl peroxide; cumyl butyl peroxide; 1,1 di-t-butyl peroxydi-3,5,5,5-trimethylcyclohexane; 2,5-dimethyl-2,5-di (t-butyl peroxy) hexane; 2,5-dimethyl-2,5-bis (t-butyl peroxy) hexino-3 and bis (a-t-butyl peroxyisopropyl benzene); peroxystere such as t-butyl peroxypivalate; t-butyl perooctoate; t-butyl perbenzoate; 2,5-dimethylhexyl-2,5-di (perbenzoate), t-butyl di (perftalate); dialkyl peroxymonocarbonates peroxydicarbonates; hydroperoxides such as t-butyl hydroperoxide, p-methane hydroperoxide, pentane hydroperoxide eumeno hydroperoxide; and ketone peroxides such as peroxide cyclohexanone and methyl ethyl ketone peroxide; Azo compounds, such as azobisisobutyronitrile can also be used.

In addition, other components known in the art may be added to the graft polymers of the present invention to further increase the properties of the final material. For example, polyethylene glycol may also be added to improve the viscosity of the melt. Other additives may also be incorporated to provide the specific properties as desired. For example, antistatic agents, pigments, dyes and the like can be incorporated into the polymer composition. The processing characteristics may additionally be improved by incorporating lubricants or slipping agents into blends made of polymers of the present invention. All these additives are generally used in relatively small amounts, usually less than 3% by weight of the final composition.

The mixture of the polylactide and the polar monomer, oligomer or polymer is subject to mechanical deformation in a suitable mixing device, such as a roller mill, Brandener Plasticorder, a single or multiple screw extruder, or any other mechanical mixing device. which can be used to mix, combine, process or manufacture polymers. A particularly desirable reaction device is an extruder having one or more ports. In a preferred embodiment, the reaction device is a co-rotating twin screw extruder, such as a twin screw combination extruder ZSK-30 manufactured by erner &; Pfeidere Corporation, of Ramsey, New Jersey. This extruder allows multiple supply and ventilation ports.

The presence of the modified polylactide or polylactide in the blends used to make fibers, films, other shaped articles reduces the water sensitivity of pure PVOH in use. Polylactide grafted with a polar monomer or with a monomer mixture is preferred for improved compatibility with PVOH in order to obtain superior processing and superior mechanical and physical properties. It is possible to use the mixtures to make shapes other than those of fibers or films and to thermally form the mixtures in complex forms.

As used herein, the term "water dispersible" means that the composition dissolves or breaks into smaller pieces of 20 mesh after being immersed in water for about 5 minutes. The term "water-disintegrable" means that the composition is broken into multiple pieces and about 5 minutes by immersion in water and that some of the pieces will be caught by a 20-mesh grid if it slides through it in a manner equal to A thread through the eye of a needle The term "weakened in water" means that the compositions remain in one piece but they weaken and lose their stiffness after 5 minutes of immersion in the water and become bent, for example, bend without an external force applied to them, when they are held on one side in a horizontal position. The term "stable water" means that the composition does not become bent after 5 minutes of immersion in the water and remains in a piez after the water response test.

As used herein, the term "graft copolymer" means a polymer produced by the combination of two or more chains of constitutionally configurationally different characteristics, one of which serves as a column backbone, and at least one of those which is attached at some point or points along the column constitutes a side chain. The molar amount of the grafted monomer, oligomer or polymer, for example, species of side chain may vary but desirably must be greater than the molar amount of parent species. The term "grafted" means a copolymer that has been created which comprises side chains or species attached at some points along the column of the parent polymer. The term "mixture" as applied to polymers means an intimate combination of two more polymer chains of constitutionally or configurationally different characteristics which are not linked to one another. Such mixtures can be homogeneous heterogeneous. Preferably, the mixture is a homogeneous mixture. (See Sperling, LH, Introduction to Physical Polymer Science, 1986, pages 44-47 which is incorporated herein by reference in its entirety.) Preferably, mixing is created by combining two or more polymers at a temperature above the point. of melted each polymer.

The present invention is illustrated in detail by the following specific examples. It is understood that these examples are illustrative embodiments and that the present invention is not limited by any of the examples or detail in the description. Rather, the appended claims herein should be broadly considered within the scope and spirit of the invention.

EXAMPLES Example 1 - Extrusion and Reaction of Polylactide with 2-hydroxyethyl methacrylate A co-rotating twin screw extruder, ZSK manufactured by Werner & Pfleiderer Corporation of Ramsey, Ne Jersey was used to make the modified polylactide from the examples. The diameter of the extruder was 30 millimeters. The length of the screws was 1388 millimeters. This extruder had 14 barrels, consecutively numbered 1 to 14 from the supply hopper to the matrix. The first barrel, the barrel 1, received the polylactide and was not heated, but cooled with water. The vinyl monomer, 2-hydroxyethyl methacrylate, was grafted into barrel # 5 and LUPERSOL 101 peroxide Atochen, was injected into barrel # 6. Both monomer and peroxide were injected through a pressurized nozzle injector. A vacuum port for the devolatilization was included in barrel # 11. The matrix used to extrude the modified polylactide yarns had four 3 mm diameter openings which were separated by 7 mm. The modified polylactide threads were then cooled in a cold water bath and then pelleted.

The polylactide was fed into the extruder with a volumetric feeder at a rate of 20 pounds per hour.

The 2-hydroxyethyl methacrylate and the peroxide were injected into the extruder at rates of 1.8 pounds / hour and 0.0 hours / hour respectively. The screw speed was 30 revolutions per minute.

The following extruder barrel play temperatures were used during the extrusion run: Zone 1 Zone 2 Zone 3 Zone 4 Zone 5 Zone 6 Zone 7 180 ° C 180 ° C 180 ° C 180 ° C 180 ° C 170 ° C 160 ° C The vacuum was turned on for the devolatilization in barrel # 11 and the process was allowed to stabilize. The strands of polylactide grafted with extruded 2-hydroxyethyl methacrylate (PLA-g-HEMA) were cooled in a cold water bath and then pelleted.

The melting rheology tests were carried out on the modified polylactide and not modified on a Goettfert Rhoegraph 2000 (available from Goettfert Rock Hill, South Carolina). The improved polylactide of this example was prepared with 9% by weight of 2-hydroxyethyl methacrylate ® and 0.45% by weight of LUPERSOL initiator. The percentages of pes of 2-. { hydroxyethyl methacrylate and LUPERSOL initiator were based on the weight of polylactide.

The melting rheology tests were carried out at 180 ° C with a matrix of 30/1 (length / diameter) mm / mm The apparent melt viscosity was determined at apparent cut-off rates of 50, 100, 200, 500, 1000, and 2000 l / s. A rheology curve was drawn for each apparent viscosity material against the apparent cutoff rates given below.

The apparent melt viscosities at the various apparent cut-off rates were drawn and the rheology curves for the unmodified polylactide and the modified polylactide from the example above were generated as shown in Figure 2. The rheology curve of the modified polylactide demonstrates the reduced and unexpected viscosities of modified polylactide when compared to the modified n-polylactide. These reduced viscosities of the modified polylactide result in improved processability of polylactide. The grafting of polar monomers, polymer oligomers in the polylactide results in an improved compatibilida with both polar materials and polar substrates.

Example 2 - Fibers Made of Mixtures Comprising Polyvinyl Alcohol and Modified Polylactide or Non-Modified Polylactide The fibers that respond to the water of the following example are composed of a mixture of melted polyvinyl alcohol (PVOH) and either modified polylactide or polylactide as modified in example 1. The range of the compositions for the fibers that respond to water it varies from about 1 about 99% by weight of modified or unmodified polylactide in the mixture. The modified polylactide used in the mixtures is as described above in Example 1 and the unmodified polylactide used in the mixtures is that as supplied by Aldrich Chemical Company. The polyvinyl alcohol used in the mixtures was Ecomaty AX1000 supplied by Nippon Gohsei, from Japan and is a polymer soluble in cold water synthesized from a partially hydrolyzed polyvinyl acetate and containing side chain branches. The melt flow rate of the polyvinyl alcohol used was 100 g / 1 min at 230 ° C and 2.16 kg.

Extrusion Process of the Polymer Blend Mixture compositions that respond to the agu were prepared by a melt extrusion process. S prefers to mix or combine the two components in an extruder such as a twin screw or a single screw extruder under appropriate temperature and cut / pressure conditions. The mixing process can be carried out in a blender type loading device such as a melting kneading mixer, which is discussed in the next section. Both the polyvinyl alcohol and the modified or unmodified polylactide can be fed to an extruder either simultaneously or in sequence to minimize any adverse effects on polymers such as degradation or discoloration.

In this example, the extrusion process of the samples was carried out using a Haake TW-100 counter-rotating gemel screw extruder. The extrusion placement temperatures for the four heating zones were 170, 180, 180 and 168 ° C. The screw speed was 15 revolutions per minute. A mixture of polylactide modified polylactide resin and polyvinyl alcohol was fed to the extruder at a rate of 10 pounds / hour. The melted was extruded, cooled by air and then pelletized.

The mixed and extruded compositions which contained 20, 30 and 40% by weight of either modified polylactide polylactide of Example 1 and 80, 70 and 60% by weight of polyvinyl alcohol respectively were produced and used for fiber spinning.

Melt Mixing Process for the Mixing of Polymer Mixture compositions that respond to the agu were prepared by a melt mixing process. In this example, the melt mixing process was carried out using a twin roller mixer, contragiratori® Haake, RHEOMIX 600. The temperature of the mixer was 180 ° C. The screw speed was 150 revolutions per minute. Seventy grams of the total resin mixture was fed into the mixer and mixed for 5 minutes. The melted was removed from the mixer and then cooled in air.

The melt mixer compositions, which contained 50 and 60% by weight of either modified polylactide polylactide of Example 1 and 50 and 40% by weight of polyvinyl alcohol were produced and used for the fiber side.

Fiber Processing of Mixtures The fibers were made on a small scale fiber spinning processing equipment. The device consists of a vertically mounted cylinder heated by cartridge heaters. A vertically mounted device Worm Gear Jactuator (Model: PKN-1801-3-1, manufactured by Duff Northon Company, of Charlotte, North Carolina) was used to extrude the materials into the fibers.

The fibers were spun with a hilad plate with three openings of 0.356 millimeters. The fibers exiting the matrix were wound on a drum that had both reciprocating and rotating movements to collect the fiber samples.

The fibers were prepared with several amounts of polyvinyl alcohol and the unmodified polylactide or unmodified polylactide of example 1.

Example A) Ratio fibers by weight of 20/80 polyvinyl alcohol of polyvinyl alcohol.

The cylinder temperature was set at 360 ° C. This temperature made soft fibers made of this polymer mixture which was composed of unmodified polylactide of vinyl alcohol of polymer. The fibers were lightly yellow.

Example B) Weight ratio fibers of 20/80 d polylactide-g-2-hydroxyethyl methacrylate / polyvinyl alcohol.

This sample was made in the polylactide grafted with 2-hydroxyethyl methacrylate and the polyvinyl alcohol. The temperature of the barrel was also set at 360 ° C. This polymer blend was made into fibers of less color than the fibers made from the unmodified mixture mentioned above. These fibers were almost colorless. The polymer blend exhibited essentially superior melt strength to that of the mixture containing the unmodified polylactide presumably due to improved compatibility of the polylactide grafted with 2-hydroxyethyl methacrylate with polyvinyl alcohol. As a result, the fibers and films can be extruded friction rates higher than those of the mixtures containing the unmodified polylactide. The fibers can be produced in a temperature range from 353 to 371 ° C.

Example C) Weight ratio fibers of 30/70 d polylactide / polyvinyl alcohol This blend composition was also spun into fibers. The melt fracture occurred.

Example D) Weight ratio fibers of 30/70 d polylactide-g-2-hydroxyethyl methacrylate / polyvinyl alcohol.

The soft and almost colorless fibers were made from this blend composition. This mixture showed some improved processability on the 30/70 unmodified polylactide / polyvinyl alcohol mixture.

Example E) Fiber ratio by weight of 40/6 polylactide / polyvinyl alcohol.

Example F) Weight ratio fibers of 40/60 polyvinyl alcohol-g-2-hydroxyethyl methacrylate.

Example G) Mixed fibers proportion by weight of 50/5 polylactide / polyvinyl alcohol Example H) Mixed fibers, weight ratio, 50/5 polylactide-g-2-hydroxyethyl methacrylate / polyvinyl alcohol.

Example I) Mixed fibers, weight ratio of 60/4 polylactide / polyvinyl alcohol.

Example J) Mixed fibers, weight ratio of 60/4 polylactide-g-2-hydroxyethyl methacrylate / polyvinyl alcohol.

The mixtures containing polylactide 2 grafted with 2-hydroxyethyl methacrylate have lower viscosities than the mixtures containing the unmodified polylactide and can therefore be extruded at higher rates and exhibited improved processability. Additionally, fibers made from the mixtures containing the modified polylactide exhibited less discoloration of the fibers of the mixtures containing the unmodified polylactide, suggesting improved compatibility of the modified polylactide. All mixtures containing the modified polylactide with 2-hydroxyethyl methacrylate exhibited superior melting strength and better fiber processability than those containing the modified polylactide mixtures at the same proportions by weight.

Water Response Test of Polilactid Fibers Injeated with 2-hydroxyethyl methacrylate / polyvinyl alcohol.

For each of the above mentioned compositions, a section of prepared midiend fibers was cut about 1 inch. The diameter of the fiber was measured and recorded. The water response test involved using a pair of tweezers to hold the section of the fibers, immersing it in a scintillation bottle filled with 20 milliliters of water, holding it there for 5 minutes. After 5 minutes, the lid was placed on the container and the container was placed in a model 75 (available from Burrell Corporation, Pittsburgh, Pennsylavania). The vessel was agitated for 30 seconds with the agitator set at the maximum speed. If the fiber began to disperse and disintegrate, the contents of the container were emptied through a 20-mesh grid (standard 20-mesh screen from the United States of America ASTM E-ll Description No. 20). The container was rinsed with 2 millimeters of water with a bottle that can be tightened to remove any remaining fiber pieces and empty them through the screen. If the fiber did not disperse or disintegrate, the fiber was observed for any loss and stiffness.

Map of Response to Water for Compositions of Fiber mixtures in Mixer and Extruder Percent by weight of modified or unmodified polylactide in mixtures with polyvinyl alcohol 1 40 50 60 99 Disability Fibers made from blend compositions were dispersible in water to about 40% by weight of unmodified modified polylactide in the mixture. The fibers were made of blends with about 60 or more percent by weight of modified or unmodified polylactide and were stable in water. The fibers were made from mixtures between these two range and should be considered weakened in water. The fibers made from the blends with about 50% by weight of modified or modified polylactide n were weakened in water.

Example 3 - Films made from blends comprising modified polylactide or unmodified polylactide and polyvinyl alcohol.

The films that respond to the water of the following examples are composed of melted mixtures of modified or unmodified polylactide and polyvinyl alcohol. The range of compositions for films that respond to water it varies from 1 to 99 percent by weight of the modified and unmodified polylactide in the mixture. The presence of polylactide or modified polylactide in the mixture used to make the films reduces the water sensitivity of the pure polyvinyl alcohol in use. Polylactide grafted with either polar monomer or monomer mixture is preferred for increased compatibility with polyvinyl alcohol in order to obtain superior mechanical or physical properties. The modified polylactide used in the blends as described above in Example 1 and the unmodified polylactide used in the blends was that as supplied by Aldrich Chemica Company. The polyvinyl alcohol used in the mixtures was Ecomat AX10000 supplied by Nippon Gohsei, Japan, a cold water soluble polymer synthesized from partially hydrolyzed polyvinyl acetate containing side branches.

Extrusion process for polymer blend Mixture compositions that respond to the agu were prepared by an extrusion process. It is preferred to mix or combine the two components in an extruder such as a twin extruder or even a single screw extruder under suitable cutting and pressure and temperature conditions. The mixing process can also be carried out in a load mixing device such as a melted mixer or a kneader, which is discussed in the following section. Both the polyvinyl alcohol and the modified polylactide can be fed to an extruder either simultaneously or in sequence to minimize any adverse effects on the polymers such as degradation or discoloration.

In these examples, the extrusion process of the blends was carried out using a Haake T-100 counter-rotating gemel screw extruder. The temperatures extruded for the four heating zones were 170 ° C, 180 ° C and 168 ° C. The screw speed was 150 revolutions per minute. A mixture of polylactide resin or modified polylactide and polyvinyl alcohol was fed to the extruder at a rate of 10 pounds / hour. The melted was extruded cooled with air and then polietized.

The extruded blend compositions, which contained 20, 30 and 40% by weight of the unmodified polylactide or modified polylactide, and 80, 70 and 60 percent by weight of polyvinyl alcohol respectively were produced and used to make films in this example.

Melt mixing process for the polymer combination.

Mixture compositions that respond to the agu were then prepared by a melting d process. In these examples, the melt mixing process was carried out using a Haake RHEOMIX® 600 counter-rotating gemel roll mixer. The set mixer temperature was 180 ° C. The screw speed was 15 revolutions per minute. 70 grams of the total resin mixture were fed to the mixer and combined for 5 minutes. The melt was removed from the mixer and then cooled to air.

The melt mix compositions, which contain 30, 40, 50 and 60 percent by weight of HEMA grafted polylactide and 70, 60, 50 and 40 percent polyvinyl alcohol, respectively, were produced to make the films in this example.

Film preparation A film was prepared for each mix composition using a hot Carver press with two plates heated at a temperature of 190 ° C and at a pressure of 15.00 pounds per square inch for about one minute. The thickness of the films in this example was approximately 4 mils. However, the thickness of the films can be either increased or decreased depending on the final use and the desired properties.

Water response test of polilactid films grafted with HEMA of polyvinyl alcohol.

For each of the compositions a section of the prepared film was cut by measuring about one quarter of an inch by about one-half inch. The water response test involved using a pair of tweezers to hold the section of the film by immersing it in a scintillation container filled with 20 milliliters of water and holding it there for 5 minutes. After 5 minutes, the lid was placed on the container and said container was placed on a shaker, model 75 (available from Burrell Corporation, of Pittsburgh, Pennsylvania). The vessel was agitated for 30 seconds with the agitator set at a maximum speed. If the film began to disperse or disintegrate, the contents of the container were emptied through a 20-mesh screen (standard US 20-mesh test screen, ASTM E-l Description No. 20). The vessel was then rinsed with 2 milliliters of water from a squeeze bottle to remove any remaining pieces of film and was emptied through the screen. If the film did not disperse or disintegrate, the film was observed for any loss of stiffness.

Water Response Map for Film Compositions Mixed in Extruder and Mixer Percent by weight of modified or unmodified polylactide in mixtures with polyvinyl alcohol 1 < - • > 40 50 60 < > 99 Dispersable Weakable Stable Films made from the blended compositions were dispersible in water up to about 40% by weight of the modified or unmodified polylactide in the mixture. The films were made from blends with about 60 or more percent by weight of the modified or unmodified polylactide were stable in the water. The fibers were made of mixture between these two ranges and should be considered as water weakening. The fibers made from blends with about 50% by weight of modified or unmodified polylactide were weakened in water.

It is understood that these examples are illustrative modality and that this invention should not be limited by any of these examples or details of the description. Rather, the claims appended here should be broadly considered within the scope and spirit of the invention. Particularly, it should be understood that the invention includes, but is not limited to compositions, films, fibers and articles in which the claimed composition, film or fiber is a component of the final product.

Claims (40)

1. A polymer composition comprising a polylactide grafted with a polar monomer, oligomer, polymer or a combination thereof.

2. The polymer composition as claimed in clause 1, characterized in that said polar monomer is an ethylenically unsaturated monomer containing at least one polar functional group or said oligomer or dich polymer is an oligomer or a polymer polymerized from an ethylene monomer unsaturated that contains at least one polar functional group.

3. The polymer composition as claimed in clause 2, characterized in that said at least one polar functional group is a hydroxyl, carboxyl or sulfonate group or a combination thereof.

4. The polymer composition as claimed in clause 3, characterized in that said at least one functional polar group is a hydroxyl group.

5. The polymer composition as claimed in clause 1, characterized in that the polar monomer is a polar vinyl monomer.

6. The polymer composition as claimed in clause 1, characterized in that said polar monomer, oligomer or polymer is selected from the group consisting of 2-hydroxyethyl methacrylate and polyethylene glycol methacrylate and derivatives thereof.

7. The polymer composition as claimed in clause 6, characterized in that said polar monomer, oligomer or polymer is 2-hydroxyethyl methacrylate or its derivatives.

8. The polymer composition as claimed in clause 6, characterized in that dich polylactide contains from 1 to 20 weight percent grafted polar monomer, oligomer or polymer or combinations thereof.

9. The polymer composition as claimed in clause 1, characterized in that dich polylactide is mixed confused with a second polymer.

10. The polymer composition as claimed in clause 1, characterized in that said composition is dispersed in water, weak in water or established in water.

11. A polymer composition comprising a polylactide column with a plurality of oligomeric polar monomers, polymers or mixtures thereof, grafted onto said polylactide column.

12. A method for making a grafted polylactide composition comprising the steps of: a) combining a polylactide and a polar monomer, oligomer or polymer in a reaction vessel; Y b) providing sufficient energy to the combination of said polylactide and said polar monomer, oligomer or polymer in order to form said grafted polylactide composition.

13. The method as claimed in clause 12, characterized in that said reaction vessel is an extruder.

14. The method as claimed in clause 13, characterized in that said extruder is a co-rotating twin screw extruder.

15. The method as claimed in clause 12, characterized in that said polar monomer is an ethylenically unsaturated monomer containing at least one polar functional group or said oligomer or said polymer is either an oligomer or a polymer polymerized from an ethylenically unsaturated monomer which It contains at least one polar functional group.

16. The method as claimed in clause 15, characterized in that said at least one polar functional group is a hydroxyl, carboxyl or sulfonat group or a combination thereof.

17. The method as claimed in clause 12, characterized in that said polar monomer is a polar vinyl monomer.

18. The method as claimed in clause 12, characterized in that said monomer, polymer oligomer is selected from the group consisting of 2-hydroxyethyl methacrylate and polyethylene glycol methacrylate and its derivatives.

19. The method as claimed in clause 12, characterized in that said sufficient energy s provides in the form of heat.oho

20. The method as claimed in clause 12, characterized in that an initiator is added to the mixture.

21. A film or fiber comprises a mixture of a polyvinyl alc and a polylactide.

22. The film or fiber as claimed in clause 21, characterized in that said modified polylactide.

23. The film or fiber as claimed in clause 22, characterized in that said polylactide is grafted with a polar monomer, oligomer or polymer or a combination thereof.

24. The film or fiber as claimed in clause 23, characterized in that said polar monomer is an ethylenically unsaturated monomer containing at least one polar functional group or said oligomer or said polymer is either an oligomer or a polymer polymerized from an ethylenically unsaturated monomer which contains at least one polar functional group.

25. The film or fiber as claimed in clause 24, characterized in that at least one polar functional group is a hydroxyl, carboxyl or sulfonate group a combination thereof.

26. The film or fiber as claimed in clause 25, characterized in that said at least one polar functional group is a hydroxyl group.

27. The film or fiber as claimed in clause 24, characterized in that said polar monomer is a vinyl monomer.

28. The film or fiber as claimed in clause 23, characterized in that said polar monomer, oligomer or polymer is selected from the group consisting of 2-hydroxyethyl methacrylate and polyethylene glycol methacrylate derivatives thereof.

29. The film or fiber as claimed in clause 27, characterized in that said polar monomer, oligomer or polymer is selected from the group consisting of 2-hydroxyethyl methacrylate and its derivatives.

30. The film or fiber as claimed in clause 21, characterized in that said mixture comprises from about 1 to about 99 weight percent poly (vinyl alc) and from about 1 to about 99 weight percent polylactide.

31. The film or fiber as claimed in clause 21, characterized in that said mixture comprises from about 40 to about 80 weight percent poly (vinyl alc) and from about 20 to about 60 weight percent polylactide.

32. The film or fiber as claimed in clause 30, characterized in that said mixture comprises from about 1 to about 40 percent polylactide and e dispersible in water.

33. The film or fiber as claimed in clause 30, characterized in that said mixture comprises from about 40 to about 60% by weight of polylactide and e weak in water.

34. A method for making a film or fiber comprising the steps of: a) mixing a polyvinyl alc with polylactide; Y b) Extrude a film or fiber from the mixture.

35. The method as claimed in clause 34, characterized in that said polylactide is modified before mixing with polyvinyl alc.

36. The method as claimed in clause 35, characterized in that said polylactide is modified by the steps comprising: a) combining a polylactide and a polar monomer, oligomer or polymer in a reaction vessel; Y b) providing sufficient energy to the combination of said polylactide and said polar monomer, oligomer or polymer in order to modify said polylactide.

37. The method as claimed in clause 34, characterized in that the film or fiber is dispersible in water and comprises about 1 to about 40 by weight of polylactide and about 60 to about 99 weight percent of poly (alc) vinyl).

38. The method as claimed in clause 34, characterized in that the fiber or film is weak in water and comprises about 60 weight percent polylactide and about 40 weight about 60 weight percent poly (vinyl alc). .

39. The method as claimed in clause 34, characterized in that the film or fiber is established in water and comprises from about 60 to about 99 per cent by weight of polylactide and from about 1 to about 40 per cent by weight of poly. (vinyl alcohol)

40. The method as claimed in clause 34, characterized in that the mixture is made by melt extrusion.