CN117624563A

CN117624563A - High-melt-strength polyglycolide material and preparation method thereof

Info

Publication number: CN117624563A
Application number: CN202210997325.6A
Authority: CN
Inventors: 周炳; 王洪学; 骆佳伟; 田雨川; 贾钦
Original assignee: China Petroleum and Chemical Corp; Sinopec Shanghai Research Institute of Petrochemical Technology
Current assignee: China Petroleum and Chemical Corp; Sinopec Shanghai Research Institute of Petrochemical Technology
Priority date: 2022-08-19
Filing date: 2022-08-19
Publication date: 2024-03-01

Abstract

The invention relates to the technical field of polymer synthesis, and discloses a high-melt-strength polyglycolide material and a preparation method thereof. The polyglycolide material comprises a polymer A and a polymer B, wherein the polymer A is a polyvinyl alcohol-polyglycolide copolymer, and the polymer B is polyglycolide. The polyglycolide material overcomes the defects in the prior art, has the advantages of high melt strength, large molecular weight, high toughness, lower melt flow rate and the like, is suitable for processing of film-grade application, and the obtained product has good toughness and high strength and can meet the application requirements.

Description

High-melt-strength polyglycolide material and preparation method thereof

Technical Field

The invention relates to the technical field of polymer synthesis, in particular to a high-melt-strength polyglycolide material and a preparation method thereof.

Background

Polyglycolide (PGA) has excellent mechanical properties against O ₂ And CO ₂ The barrier property of the polymer is strong, the polymer is nontoxic, harmless and environment-friendly, and the polymer is authenticated by safely biodegradable plastic materials in the United states, european Union and Japan.

However, on the one hand, the polyglycolide has poor toughness, the elongation at break is only about 10%, and the notched impact strength is less than 3kJ/m ² The method comprises the steps of carrying out a first treatment on the surface of the On the other hand, the molecular weight of the polyglycolide obtained by the traditional preparation method is still not high enough, the melt flow rate at the processing temperature is too high, the melt strength is too low, so that film products are difficult to obtain by adopting processing modes such as casting, film blowing and the like, and the application of the polyglycolide in the corresponding field is severely limited.

CN112513133 a (Shanghai Pu Jing chemical technology limited, 2021.03.16) relates to a novel polyglycolic acid. The polyglycolic acid in this patent is modified after polymerization by chain extension with isocyanate to give a melt strength of 5 to 30cN at 230 ℃. However, on the one hand, the isocyanate has higher toxicity, and the biodegradability of the obtained polyglycolic acid is also reduced by modification of the isocyanate. On the other hand, the method needs to carry out post-modification after polymerization, and the process steps are complicated. In addition, the method is a low-temperature nitrogen protection reaction, the reaction condition is more severe, the reaction time is longer, the whole process takes at least 160 minutes (min), and long reaction time can lead to thermal decomposition or degradation of PGA to form byproducts with color or peculiar smell, thereby obviously reducing the quality of PGA products and limiting the application range.

CN 113683756A (russian medical equipment limited, hangzhou, 2021.11.23) discloses a method for synthesizing polyglycolide, application of polyglycolide and synthesizing device, which adopts different temperatures to reduce intramolecular transesterification and intermolecular transesterification, and simultaneously reduce side reactions such as degradation, thereby facilitating forward progress of reaction and increasing molecular weight of polyglycolide. However, the resulting polyglycolide has still poor toughness, with an elongation at break of only about 2%. Moreover, the preparation process is longer, the reaction time is 5-96 hours (h), the cost is higher, and the thermal decomposition of PGA is easy to cause.

In summary, there is a continuing need in the art to improve the melt strength and melt toughness of polyglycolides and to improve the blown film processability of the polyglycolides. Therefore, how to simultaneously improve the melt strength and the melt toughness and reduce the melt flow rate is an urgent problem to be solved in the film-grade application process of the existing polyglycolide.

Disclosure of Invention

Aiming at the technical problems that the molecular weight, the melt strength and the melt toughness of the polyglycolide are low and the melt flow rate is high in the prior art, so that the direct film blowing processing cannot be satisfied, the invention provides a high-melt-strength polyglycolide material and a preparation method thereof. The polyglycolide material overcomes the defects in the prior art, has the advantages of high melt strength, large molecular weight, high toughness, lower melt flow rate and the like, is suitable for processing of film-grade application, and the obtained product has good toughness and high strength and can meet the application requirements.

It is an object of the present invention to provide a polyglycolide material comprising a polymer a which is a polyvinyl alcohol-polyglycolide graft copolymer and a polymer B which is a polyglycolide.

In a preferred embodiment of the present invention, the main chain of the polyvinyl alcohol-polyglycolide graft copolymer a is an ethylene-vinyl alcohol copolymer, the side chain is polyglycolic acid, and the structural formula of the copolymer a is shown in formula (i):

wherein x, y, z, p is an integer, and the sum of x+y+z is not less than 100.

In a preferred embodiment of the present invention, the polymer B comprises a polyglycolide of formula (II);

m in formula (II) ₁ ，M ₂ ，……，M _i Identical or different, each being an imino, a phosphino or an ether linkage, R being an alkanyl or an aromatic hydrocarbon radical having a molecular weight of from 14 to 1000g/mol (e.g.i>1 time); n is n ₁ ，n ₂ ，……，n _i Each is a positive integer, i is a positive integer; when i=1, R may be a hydrogen atom or a hydrocarbon group.

According to the invention, the sum of x+y+z in formula (I) can be selected within a wide range, and in a preferred embodiment of the invention the sum of x+y+z in formula (I) is 100-6000, preferably 300-2000. For example, 300, 500, 1000, 1500, 2000, any two values and any two value intervals are possible.

According to the invention, the ratio of x to the sum x+y+z can be chosen within a wide range, and in a preferred embodiment of the invention the ratio of x to the sum x+y+z in formula (I) is from 1% to 32%. For example, 1%, 5%, 10%, 15%, 20%, 25%, 30%, 32%, any two values, and any two-value intervals are possible.

According to the invention, the sum of x+y+z can be calculated by the number average molecular weight of the raw material polyvinyl alcohol, the ratio of x to the sum of x+y+z is the alcoholysis degree of the polyvinyl alcohol, and the ratio of y to z can be calculated by the integral area of the nuclear magnetic hydrogen spectrum.

According to the invention, the alcoholysis degree of the polyvinyl alcohol is a known parameter of raw material delivery, and can also be detected by a plurality of detection methods in the field, such as nuclear magnetism, near infrared and the like.

According to the invention, if the starting macroinitiator structure is known, p= (number average molecular weight of the high molecular weight fraction PGA-macroinitiator (polyvinyl alcohol) number average molecular weight)/(y PGA repeat unit molecular weight). If the high molecular weight PGA of the graft copolymer structure of the present invention is directly obtained, it may be first hydrolyzed sufficiently, the initiator is collected, and the structure thereof is analyzed and then tested in the above-described manner. According to the examples of the invention which follow, the p values in the polymers obtained were calculated to be greater than 10. The optional range of p values is broad according to the present invention, and in a preferred embodiment of the present invention, p is greater than 10, more preferably, p is greater than 50.

According to the invention, the average degree of polymerization (x, y, z, p) obtained by calculation is rounded off in the calculation.

According to a broad alternative scope of the invention, in a preferred embodiment of the invention, n in formula (II) ₁ ，n ₂ ，……，n _i The sum is not less than 50. According to the invention, n ₁ ，n ₂ ，……，n _i The sum of the values can be calculated by dividing the data molecular weight of the lower molecular weight peak in the GPC result by the molecular weight of the PGA repeating unit. According to the examples of the invention which follow, n in the resulting polymer is calculated ₁ ，n ₂ ，……，n _i The sum of the values is greater than 50.

According to the invention, the value of i can be chosen in a wide range, in a preferred embodiment of the invention i ranges from 1 to 20, and i ranges from 2 to 6, for example 2, 3, 4, 5, 6.

According to the present invention, the content of each segment is selected in a wide range, and in a preferred embodiment of the present invention, the content is selected with respect to 100 parts by mass of the polyglycolide segment(i.e., formula (I), formula (II)>Based on the total mass of the poly (glycolide) material, the poly (glycolide) material contains 0.001-10 parts by mass of a polyvinyl alcohol segmentComprises 0.001-10 parts by mass of->More preferably, relative to 100 parts by mass of the polyglycolide segment->The polyglycolide material contains 0.01-1 mass part of polyvinyl alcohol chain segment +.>Comprises 0.01-1 mass part of->The mass content of each chain segment can be detected by a method known in the art, and can also be calculated by the feeding amount in the preparation process.

According to the invention, the polymer A has a broad range of weight average molecular weights, and in a preferred embodiment of the invention, the polymer A has a weight average molecular weight of 50 to 1000 ten thousand g/mol, preferably 100 to 350 ten thousand g/mol. For example, 100, 150, 200, 250, 300, 350 and any two-number interval may be used.

According to the invention, the molecular weight polydispersity index of the polymer a may be selected within a wide range, and in a preferred embodiment of the invention, the molecular weight polydispersity index of the polymer a is in the range of 1.0 to 3.0, preferably 1.0 to 1.5.

According to the invention, the weight average molecular weight of the polymer B may be selected within a wide range, and in a preferred embodiment of the invention, the weight average molecular weight of the polymer B is 5 to 30 ten thousand g/mol, preferably 10 to 25 ten thousand g/mol. For example, 10 ten thousand g/mol, 15 ten thousand g/mol, 20 ten thousand g/mol, 23 ten thousand g/mol, 25 ten thousand g/mol, any two values and any two value intervals are possible.

According to the invention, the molecular weight polydispersity index of the polymer B may be selected within a wide range, and in a preferred embodiment of the invention, the molecular weight polydispersity index of the polymer B is from 1.0 to 3.0, preferably from 1.4 to 2.0.

According to the present invention, the content of the polymer a, the polymer B may be selected within a wide range, and in a preferred embodiment of the present invention, the content of the polymer a is 0.1 mass% to 80 mass%, preferably 1 mass% to 30 mass%, with respect to the total mass of the polymer a and the polymer B; the content of the polymer B is 20 to 99.9 mass%, preferably 70 to 99 mass%.

According to the present invention, the weight average molecular weight of the population of the polyglycolide material is in a wide range of choice, and in a preferred embodiment of the present invention the weight average molecular weight of the population of the polyglycolide material is in the range of 15 ten thousand to 100 ten thousand g/mol, preferably 20 ten thousand to 50 ten thousand g/mol. For example, 20 ten thousand g/mol, 30 ten thousand g/mol, 40 ten thousand g/mol, 50 ten thousand g/mol, any two values and any two value intervals are possible.

According to the present invention, the overall molecular weight distribution index of the polyglycolide material is selected to be wide, and in a preferred embodiment of the present invention, the overall molecular weight distribution index of the polyglycolide material is 1.5 to 20.0, preferably 2.0 to 3.5.

The parameters of the weight average molecular weight of the polymer a, the molecular weight polydispersity index of the polymer a, the weight average molecular weight of the polymer B, the molecular weight polydispersity index of the polymer B, the mass content of the polymer a, the mass content of the polymer B, the total weight average molecular weight of the polyglycolide material, the total molecular weight distribution index of the polyglycolide material, and the like can be detected by Gel Permeation Chromatography (GPC). Specific detection methods may employ detection parameters conventional in the art. For example, but not limited to, the following methods are employed: the test instrument was a gel permeation chromatograph model PL-GPC50 from Angilent, USA, and the process software was GPC offine. In the test, the mobile phase is hexafluoroisopropanol containing 5mmol/L sodium trifluoroacetate, the flow rate is 1mL/min, the column temperature is 40 ℃, the sample injection amount is 100 mu L, the standard sample is PMMA, and the sample concentration is 1mg/mL.

According to the invention, the melt flow rate of the polyglycolide material can be selected within a wide range, and in a preferred embodiment of the invention, the melt flow rate of the polyglycolide material at 230 ℃/2.16kg is not higher than 20g/10min, preferably 1-10g/10min. For example, it may be 1g/10min, 5g/10min, 10g/10min, any two values and any two value intervals.

The melt flow rate may be determined using methods known in the art, such as, but not limited to, the following: the test was performed on a CEAST MF20 melt flow tester from Instron, usa. The test temperature was 230℃and the load weight was 2.16kg. The preheating time was 4min.

According to the invention, the melt strength of the polyglycolide material can be selected within a wide range, and in a preferred embodiment of the invention, the melt strength of the polyglycolide material is not less than 6cN, preferably not less than 8cN, at 235 ℃.

Melt strength can be measured using methods well known in the art, such as, but not limited to, the following: the test was performed on a Rosand RH7 high pressure capillary rheometer from malvern panaceae, china. The die model is Haul Off (diameter: 2.0mm, length: 20 mm), the push rod pressing speed of the charging barrel is 15mm/min, the test temperature is 235 ℃, the initial drafting speed is 3mm/min, the final drafting speed is 50mm/min, and the accelerating time is 3min.

According to the present invention, the number of molecular weight distribution peaks of the polyglycolide material is at least 2, including, for example, but not limited to, 2, 3. According to the present invention, the number of molecular weight distribution peaks can be detected by Gel Permeation Chromatography (GPC).

Another object of the present invention is to provide a process for producing a polyglycolide material according to one of the objects, comprising polymerizing a polymer to obtain a polyglycolide segmentAnd (3) carrying out melt polymerization reaction on the monomer, polyvinyl alcohol and an optional small molecule co-initiator in the presence of a catalyst, and then cooling to obtain the polyglycolide material.

According to the present invention, the monomer may be selected from a wide range of monomers, and in a preferred embodiment of the present invention, the monomer is selected from at least one of methyl glycolate, glycolic acid, and glycolide, preferably glycolide.

According to the present invention, the degree of alcoholysis of the polyvinyl alcohol can be selected in a wide range, and in a preferred embodiment of the present invention, the degree of alcoholysis of the polyvinyl alcohol is 68 to 99%.

According to the present invention, the polymerization degree of the polyvinyl alcohol may be selected in a wide range, and in a preferred embodiment of the present invention, the polymerization degree is 100 to 6000, preferably 300 to 2000. For example, 300, 500, 1000, 1500, 2000, any two values and any two value intervals are possible.

According to the invention, the small molecule co-initiator has a wide selectable range, and in a preferred embodiment of the invention, the small molecule co-initiator is a small molecule substance with a boiling point of more than 160 ℃ and containing at least one functional group of a plurality of hydroxyl groups and amino groups; preferably, the molecular weight of the small molecule co-initiator is less than 1000g/mol, preferably 60-300g/mol. Including but not limited to: at least one of ethylene glycol, butanediol, glycerol, serinol, leucinol, pentaerythritol, sorbitol, xylitol, amino acids, phenol, hydroquinone, resorcinol, benzyl alcohol, aniline, benzylamine, p-phenylenediamine, m-phenylenediamine, hexamethylenediamine, dodecanediamine, etc.

According to the invention, the catalyst has a wide optional range, and in a preferred embodiment of the invention, the catalyst is a salt compound or an organic guanidine catalyst corresponding to at least one of IIA-VA group metal element and transition metal element; preferably, the catalyst is a salt compound corresponding to at least one of Sn, bi, mg, al, ca, fe, mn, ti and Zn, and more preferably a Sn salt.

In a preferred embodiment of the present invention, the preparation method further comprises: the melt polymerization reaction is carried out in the presence of an antioxidant.

The antioxidant according to the present invention may be selected from a wide range of antioxidants, for example, hindered phenolic and phosphite antioxidants and any combination thereof, and in a preferred embodiment of the present invention, the antioxidant is selected from hindered phenolic antioxidants and/or phosphite antioxidants. Examples include, but are not limited to, 2, 6-di-tert-butyl-p-cresol, 1, 3-tris (2-methyl-4-hydroxy-5-tert-butylphenyl) butane, 2' -methylenebis (6-tert-butyl-4-methylphenol), hexanediol bis [ beta- (3, 5-dibutyl-4-hydroxyphenyl) propionate ], tetrakis [ beta- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate ] pentaerythritol ester (such as the antioxidant Irganox1010 of Basf), N ' -bis [ beta- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionyl ] hydrazine (such as the antioxidant 1024), N, N ' -bis- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionyl) hexamethylenediamine (e.g. antioxidant 1098), N-octadecyl beta- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate (e.g. antioxidant Irganox 1076 from Basf), 1,3, 5-trimethyl-2, 4, 6-tris (3, 5-di-tert-butyl-4-hydroxybenzyl) benzene, triphenyl phosphite, tris (4-nonylphenyl) phosphite, diphenyl isooctyl phosphite, diphenyl isodecyl phosphite, mono-diphenyl di (2-ethylhexyl) phosphite, phenyl diisodecyl phosphite, tri (2-ethylhexyl) phosphite, triisodecyl phosphite, at least one of tris (dodecyl) phosphite, pentaerythritol diisodecyl phosphite, tris [2, 4-di-t-butylphenyl ] phosphite (antioxidant 168), bis (2, 4-dicumylphenyl) pentaerythritol diphosphite (e.g., antioxidant 686), and bis (2, 4-di-t-butylphenyl) propionic acid ] pentaerythritol diphosphite (e.g., antioxidant 626).

According to the invention, the total amount of antioxidants can be chosen within wide limits, and in a preferred embodiment of the invention, the total amount of antioxidants is 0 to 2 parts by mass (phr), preferably 0.01 to 1 part by mass, relative to 100 parts by mass of monomer.

According to the present invention, the amount of the polyvinyl alcohol may be selected in a wide range, and in a preferred embodiment of the present invention, the amount of the polyvinyl alcohol is 0.001 to 10 parts by mass, preferably 0.01 to 1 part by mass, relative to 100 parts by mass of the monomer.

According to the present invention, the amount of the small molecule co-initiator may be selected in a wide range, and in a preferred embodiment of the present invention, the amount of the small molecule co-initiator is 0.001 to 10 parts by mass, more preferably 0.01 to 1 part by mass, relative to 100 parts by mass of the monomer.

According to the present invention, the amount of the catalyst may be selected in a wide range, and in a preferred embodiment of the present invention, the catalyst is used in an amount of 0.005 to 0.01 parts by mass, preferably 0.01 to 0.2 parts by mass, relative to 100 parts by mass of the monomer.

According to the present invention, the conditions for melt polymerization are widely selectable, and in a preferred embodiment of the present invention, the conditions for melt polymerization include: the temperature is 160-250 ℃, preferably 200-240 ℃.

According to the invention, the time conditions for the melt polymerization reaction can be selected within wide limits, and in a preferred embodiment of the invention, the reaction time is from 0.5 to 60 minutes, preferably from 1 to 10 minutes.

In a preferred embodiment of the invention, the melt polymerization reaction is carried out in a melt mixing device; preferably, the melt mixing device is one or more of a series combination of a kettle reactor, a tubular reactor, an internal mixer, a Farrel continuous mixer, a Banbury mixer, a single screw extruder, a multi-screw extruder, and a reciprocating single screw extruder, preferably an internal mixer or a twin screw extruder.

In a more preferred embodiment of the invention, the melt polymerization is carried out in a continuous twin-screw extrusion apparatus, preferably at a processing temperature of 180 to 250 ℃, preferably 210 to 240 ℃, a screw speed of 5 to 300rpm, preferably 40 to 150rpm, and an aspect ratio of 30 to 80, preferably 40 to 70.

In a more preferred embodiment of the present invention, the melt polymerization reaction is carried out in at least two twin screw extrusion devices in series, preferably, the processing conditions of each twin screw extrusion device in series include:

the processing temperature is 180-250 ℃, preferably 210-240 ℃; and/or the screw speed is 5-300rpm, preferably 40-150rpm; and/or an aspect ratio of 30 to 80, preferably 40 to 70.

The invention also provides a polyglycolide material prepared by the preparation method.

In a preferred embodiment of the invention, the preparation is carried out in one or more twin-screw extruders in series; preferably, the processing temperature is 180-250 ℃, preferably 210-240 ℃, the screw speed is 5-300rpm, preferably 40-150rpm, the aspect ratio is 30-80, preferably 40-70.

In a preferred embodiment of the invention, the preparation process is carried out in an internal mixer; preferably, the internal mixing temperature is 180-250 ℃, preferably 200-230 ℃, the rotating speed is 5-150rpm, preferably 20-80rpm, and the reaction time is 1-20min, preferably 3-10min.

Banbury mixer arrangements suitable for use in the present invention include Banbury mixers of different designs, for example PolyLab HAAKE manufactured by Thermo Fisher, U.S.A ^TM Rheomix OS 567-1000 internal mixer modules, etc. Continuous twin screw extrusion apparatus suitable for use in the present invention include twin screw extruders of different designs, such as the HAAKE Eurolab16 bench parallel co-rotating twin screw extruder manufactured by Thermo Fisher, U.S.A., the ZSK Mcc18 or ZSK 40 equirotating parallel twin screw extruder manufactured by Coperion, germany, and the like.

The invention also provides the high melt strength polyglycolide prepared by the preparation method.

Compared with the prior art, the invention has the following advantages:

the invention overcomes the defects of low molecular weight, low melt strength and high melt flow rate of the polyglycolide in the prior art, and prepares the pure polyglycolide material which has the advantages of high melt strength, high molecular weight, high toughness, low melt flow rate and the like and is suitable for processing of film-grade application. Meanwhile, the preparation method can also realize continuous preparation on a double-screw extruder, greatly reduce the reaction time, shorten the time from a plurality of hours in the prior art to within a plurality of minutes, remarkably save energy consumption and reduce carbon emission, and the obtained product has good toughness and high strength and can meet the requirements of film-grade PGA application.

The inventors of the present invention have found that the reason is:

(1) The invention takes polyhydroxy polyvinyl alcohol as an initiator to initiate the ring-opening polymerization of the monomer, and compared with the method without the initiator, the method improves the reaction efficiency, greatly reduces the reaction time, further realizes continuous preparation on a double screw extruder, greatly reduces the reaction time, shortens the reaction time from a plurality of hours to a plurality of minutes in the prior art, obviously saves the energy consumption and reduces the carbon emission.

(2) The polyvinyl alcohol with polyhydroxy is used as the initiator, and the initiator has high molecular weight and numerous reactive centers, so that the high melt strength polyglycolide which is difficult to obtain by the traditional method can be obtained, and the low melt flow rate can be obtained.

(3) The invention adopts the initiator (polyvinyl alcohol) with higher hydroxyl value, so the molecular weight component is multi-branched polymer, and finally the polyglycolide material with higher melt strength is obtained.

(4) The invention preferably adopts a small molecular initiator containing hydroxyl or amino or ether bond as a co-initiator, can flexibly regulate and control the final molecular weight and melt flow rate of the obtained product, improves the processability of the obtained product, and simultaneously obtains a polymer with wide molecular weight distribution so as to enable the polymer to have better mechanical property.

(5) Compared with the tackifying technology of chain extension modification after using chain extenders such as isocyanate and the like in the prior art, the polyglycolic acid composition is an in-situ synthesized multimodal molecular weight distribution polyglycolic acid material, the preparation technology is a one-step method, polyglycolic acid with different molecular weight distributions is not required to be prepared by melt blending, and the unavoidable degradation of polyglycolic acid in the melt blending process of polyglycolic acid with different molecular weights is reduced. The method can be directly applied to the processing fields such as film blowing and the like without subsequent modification, and the raw materials do not contain high-toxicity substances such as isocyanate, so that the method is more environment-friendly and efficient.

Drawings

FIG. 1 is a GPC curve of some examples and comparative examples. As can be seen from FIG. 1, conventional commercial PGA is a unimodal molecular weight distribution with a peak molecular weight Mp of less than 50 ten thousand (i.e., log (M) less than 5.7), whereas examples 2 and 3 are multimodal distributions with peaks having not only a peak molecular weight Mp of less than 50 ten thousand (i.e., polymer B) but also a peak molecular weight Mp of greater than 50 ten thousand (i.e., polymer A).

FIG. 2 is a typical tensile stress strain curve for a portion of the tensile test for the example and comparative injection molded parts. As can be seen from fig. 2, examples 2 and 4 have significantly higher elongation at break than comparative example 2 (commercial PGA), i.e., toughness is significantly improved, while maintaining higher strength and modulus.

FIG. 3 shows the results of the melt strength test for some examples and comparative examples. As can be seen from FIG. 3, the melt strength at 230℃of example 2 is significantly higher than that of comparative example 2 (commercial PGA), reaching about 20cN, whereas the melt strength of comparative example 2 is less than 1cN.

Detailed Description

The present invention is described in detail below with reference to specific embodiments, and it should be noted that the following embodiments are only for further description of the present invention and should not be construed as limiting the scope of the present invention, and some insubstantial modifications and adjustments of the present invention by those skilled in the art from the present disclosure are still within the scope of the present invention.

The endpoints and any values of the ranges disclosed herein are not limited to the precise range or value, and are understood to encompass values approaching those ranges or values. For numerical ranges, one or more new numerical ranges may be found between the endpoints of each range, between the endpoint of each range and the individual point value, and between the individual point value, in combination with each other, and are to be considered as specifically disclosed herein.

The raw material sources are as follows:

the raw materials used in the invention are all commercially available.

Glycolide is purchased from Shenzhen Boli biological materials limited company, and the purity is more than or equal to 99.5 percent.

Anhydrous stannous chloride, stannous octoate, 1, 4-butandiol and serinol are all purchased from national pharmaceutical chemicals Inc., the purity of anhydrous stannous chloride, stannous octoate and serinol is AR grade, and the purity of 1, 4-butanediol is CP grade.

Antioxidant 1010 is purchased from Basiff (China) Inc., antioxidant 626 (THP-24) is purchased from Shanghai Michelin Biochemical technology Co., ltd, and the purity is not less than 95%.

Polyvinyl alcohol (PVA) is purchased from Chongqing Chuan Wei chemical Co., ltd., china petrochemical company, and has a grade of 0588, a polymerization degree of 500 and an alcoholysis degree of 88%.

Polyglycolide (PGA) was purchased from Bien-Prague, heilaceae, as GMP grade glycolide homopolymer having an average intrinsic viscosity of 1.2dl/g.

The invention performs performance measurement according to the following method:

gel Permeation Chromatography (GPC): the test instrument was a gel permeation chromatograph model PL-GPC50 from Angilent, USA, and the process software was GPC offine. In the test, the mobile phase is hexafluoroisopropanol containing 5mmol/L sodium trifluoroacetate, the flow rate is 1mL/min, the column temperature is 40 ℃, the sample injection amount is 100 mu L, the standard sample is PMMA, and the sample concentration is 1mg/mL.

Melt flow rate determination: the test was performed on a CEAST MF20 melt flow tester from Instron, usa. The test temperature was 230℃and the load weight was 2.16kg. The preheating time was 4min.

Injection molding processing method and tensile test: the samples were injection molded on a HAAKE MiniJet microinjection molding machine according to GB/T1040.2-2006 to 5A-type tensile bars (thickness: 2 mm), cylinder temperature and mold temperature were 240℃and 50℃respectively, injection molding pressure and time were 400bar and 5s respectively, and dwell pressure and time were 100bar and 10s respectively. Tensile testing was then performed on an Instron model 3344 material tester, U.S. at a tensile rate of 50mm/min and a clamp spacing of 50mm.

Melt strength test: the test was carried out on a Rosand RH7 high pressure capillary rheometer from Marvin panaceae, china, the die model was Haul Off (diameter: 2.0mm, length: 20 mm), the barrel push rod pressing speed was 15mm/min, the test temperature was 235 ℃, the initial draft speed was 3mm/min, the final draft speed was 50mm/min, and the accelerating period was 3min.

The proportions of the raw materials of some examples and comparative examples are shown in Table 1.

[ example 1 ]

The glycolide, stannous octoate, polyvinyl alcohol (PVA), 1, 4-butanediol, an antioxidant 1010 and an antioxidant 626 are uniformly mixed according to the mass ratio of 100:0.1:0.005:0.045:0.3:0.6, and then extruded and granulated by a Eurolab parallel co-rotating double screw extruder (screw diameter: 16mm and length-diameter ratio: 40). The extruder has 11 sections from a feeding port to a die, and the number of the sections is 1-11, wherein the section 1 only plays a role of feeding and cannot be heated. The temperatures of the sections 2 to 11 of the extruder are respectively as follows: 160 ℃,200 ℃,220 ℃,220 ℃,220 ℃,220 ℃,230 ℃,235 ℃, and 240 ℃. The feeding speed was 3kg/h and the screw speed was 150rpm.

[ example 2 ]

The synthesis was the same as in example 1 except that the equipment was changed to Labtech parallel co-rotating twin screw extruder (screw diameter: 20mm, length-diameter ratio: 40), and the mass ratio of glycolide, stannous octoate, polyvinyl alcohol (PVA), 1, 4-butanediol, antioxidant 1010 and antioxidant 626 was changed to 100:0.1:0.015:0.035:0.5:0.3. The specific proportions are shown in Table 1.

[ example 3 ]

The synthesis was the same as in example 2 except that the mass ratio of glycolide, stannous octoate, polyvinyl alcohol (PVA), 1, 4-butanediol, antioxidant 1010 and antioxidant 626 was changed to 100:0.1:0.05:0.05:0.5:0.3. The specific proportions are shown in Table 1.

[ example 4 ]

The synthesis was the same as in example 3, but without 1, 4-butanediol, and the amount of antioxidant was slightly adjusted, i.e., the mass ratio of Glycolide (GA) to antioxidant 626 was changed to 100:0.5. the specific proportions are shown in Table 1.

[ example 5 ]

The procedure was as in example 2, but without the addition of antioxidant 1010 and antioxidant 626. The specific proportions are shown in Table 1.

[ example 6 ]

The synthesis was the same as in example 2, except that equal amounts of serinol were used instead of 1, 4-butanediol.

Comparative example 1

The synthesis method is the same as that of example 3, but polyvinyl alcohol (PVA) is not added, the dosage of the antioxidant is slightly adjusted, and the mass ratio of glycolide to the antioxidant 1010 to the antioxidant 626 is changed to 100:0.3:0.6. the specific proportions are shown in Table 1.

Comparative example 2

Commercial pure PGA, GMP grade glycolide homopolymer, had an average intrinsic viscosity of 1.2dl/g.

TABLE 1

Note that: the proportions in the above tables are based on the mass of glycolide monomer equal to 100 parts by mass (phr).

[ test example 1 ]

Molecular weight characterization was performed by GPC for all examples and comparative examples, analytical results are shown in Table 2, and GPC curves for some examples and comparative examples are shown in FIG. 1.

TABLE 2

* Calculated from the ratio of the integral areas of the GPC curves. (GPC curve ordinate and abscissa relate to the mass and molecular weight of a polymer, respectively, so that integration of the curve gives the corresponding component mass, i.e. the ratio of integrated area to integrated total area is the corresponding mass ratio.)

As can be seen from FIG. 1, in all examples, a multimodal molecular weight distribution appears, which is a unique PGA, and the larger peak weight average molecular weight of the molecular weight is greater than 100 ten thousand g/mol. It can also be seen from Table 2 that the overall weight average molecular weight is also greater than 15 ten thousand g/mol, the overall molecular weight distribution is also much broader than the comparative examples, and the overall molecular weight distribution index is greater than 2.

[ detection example 2 ]

Melt flow rate tests were performed on some of the examples and comparative examples to characterize their melt flow rates at processing temperatures, and the test results are shown in table 3.

TABLE 3 Table 3

	MFR(g/10min)
		Example 1	16.0
Example 2	9.9
		Example 3	2.8
Example 4	1.4
		Comparative example 1	26.2
Comparative example 2	41.1

As can be seen from Table 3, the melt flow rates of each example were significantly lower than those of comparative examples 1 and 2, with lower melt fingers being advantageous for their use in the casting and blown film processing fields.

[ test example 3 ]

Mechanical properties were measured for some examples and comparative examples, and samples were injection molded into 5A tensile bars (thickness: 2 mm) on a HAAKE MiniJet microinjection molding machine according to GB/T1040.2-2006. Tensile testing was then performed on an Instron model 3344 material tester, U.S. at a tensile rate of 50mm/min and a clamp spacing of 50mm. Typical stress strain curves for tensile testing are shown in FIG. 2 and specific analysis results are shown in Table 4.

TABLE 4 Table 4

As can be seen from Table 4, the high melt strength polyglycolides obtained according to the invention have a significantly improved toughness compared with conventional polyglycolides. Example 2 (or example 4) was comparable to the highest tensile strength of comparative example 2, but the tensile modulus, elongation at break and energy at break were all significantly improved, with the elongation at break and energy at break of example 2 being significantly improved, up to 43.9% and 7.9J, 6.4 and 7.2 times that of comparative example 2, respectively.

Fig. 2 shows that the comparative example 2 (PGA homopolymer) injection molded bars are typically brittle fracture, whereas the inventive example 2 injection molded bars of example 4 are ductile fracture, have high elongation at break and a long yield plateau (from example 2 about 10% to 30%; from example 4 about 10% to 50%) on the tensile stress-strain curve, a particular high toughness, polyglycolic acid tensile property with yield characteristics that was a totally unexpected finding in polyglycolic acid material properties.

[ detection example 4 ]

Melt draw tests were performed at 235 c to characterize the melt strength for some of the examples and comparative examples, with the test results shown in table 5 and fig. 3.

TABLE 5

	Melt Strength (cN)
		Example 1	8
Example 2	20
		Comparative example 1	3
Comparative example 2	0.3

As can be seen from Table 5, the melt strength of the polyglycolides obtained according to the invention (examples 1 and 2) is significantly improved compared with the polyglycolide homopolymers (comparative examples 1 and 2). The improvement in melt strength from 0.3cN (comparative example 2) to 20cN (example 2) over a 60-fold increase in magnitude is well demonstrated by the unique unexpectedly high melt strength of the polyglycolic acid compositions of the present invention.

It should be noted that the above-described embodiments are only for explaining the present invention and do not constitute any limitation of the present invention. The invention has been described with reference to exemplary embodiments, but it is understood that the words which have been used are words of description and illustration, rather than words of limitation. Modifications may be made to the invention as defined in the appended claims, and the invention may be modified without departing from the scope and spirit of the invention. Although the invention is described herein with reference to particular means, materials and embodiments, the invention is not intended to be limited to the particulars disclosed herein, as the invention extends to all other means and applications which perform the same function.

All publications, patent applications, patents, and other references mentioned in this specification are incorporated herein by reference in their entirety. Unless defined otherwise, all technical and scientific terms used herein have the meaning commonly understood by one of ordinary skill in the art. In case of conflict, the present specification, definitions, will control.

When the specification derives materials, substances, methods, steps, devices, or elements and the like in the word "known to those skilled in the art", "prior art", or the like, such derived objects encompass those conventionally used in the art at the time of the application, but also include those which are not currently commonly used but which would become known in the art to be suitable for similar purposes.

The endpoints of the ranges and any values disclosed in this application are not limited to the precise range or value, and the range or value should be understood to include values approaching the range or value. For numerical ranges, one or more new numerical ranges may be found between the endpoints of each range, between the endpoint of each range and the individual point value, and between the individual point value, in combination with each other, and are to be considered as specifically disclosed herein. In the following, the individual technical solutions can in principle be combined with one another to give new technical solutions, which should also be regarded as specifically disclosed herein.

In the context of this specification, any matters or matters not mentioned are directly applicable to those known in the art without modification except as explicitly stated.

Moreover, any embodiment described herein can be freely combined with one or more other embodiments described herein, and the technical solutions or ideas thus formed are all deemed to be part of the original disclosure or original description of the present invention, and should not be deemed to be a new matter which has not been disclosed or contemplated herein, unless such combination is clearly unreasonable by those skilled in the art.

Claims

1. A polyglycolide material comprising a polymer a that is a polyvinyl alcohol-polyglycolide graft copolymer and a polymer B that is a polyglycolide homopolymer.

2. The polyglycolide material of claim 1, wherein the polymer is selected from the group consisting of:

the main chain of the polyvinyl alcohol-polyglycolide graft copolymer A is an ethylene-vinyl alcohol copolymer, the side chain is polyglycolic acid, and the structural formula of the copolymer A is shown as formula (I):

wherein x, y, z, p is an integer, and the sum of x+y+z is not less than 100;

and/or the polymer B comprises polyglycolide shown in a structural formula (II);

m in formula (II) ₁ ，M ₂ ，……，M _i Identical or different, each being an imino, a secondary amino or an ether linkage, R being an alkanyl or aromatic radical having a molecular weight of from 14 to 1000 g/mol;

n ₁ ，n ₂ ，……，n _i each is a positive integer, and i is a positive integer.

3. The polyglycolide material of claim 2, wherein the polymer is selected from the group consisting of:

the sum of x+y+z in formula (I) is 100-6000, preferably 300-2000; and/or the number of the groups of groups,

the ratio of x to the sum of x+y+z in formula (I) is 1% to 32%, and/or p is greater than 10, preferably greater than 50; and/or the number of the groups of groups,

n in formula (II) ₁ ，n ₂ ，……，n _i The sum is not less than 50; and/or i ranges from 1 to 20, with i preferably ranging from 2 to 6.

4. The polyglycolide material of claim 2, wherein the polymer is selected from the group consisting of:

relative to 100 parts by mass of the polyglycolide segmentThe polyglycolide material contains 0.001-10 parts by mass of polyvinyl alcohol chain segment +.>Contains 0.001-10 parts by massPreferably, the method comprises the steps of,

relative to 100 parts by mass of the polyglycolide segmentThe polyglycolide material contains 0.01-1 mass part of polyvinyl alcohol chain segment +.>Comprises 0.01-1 mass part of->

5. The polyglycolide material according to one of claims 1 to 4, characterized in that:

the total weight average molecular weight of the polyglycolide material is 15 ten thousand-100 ten thousand g/mol, preferably 20 ten thousand-50 ten thousand g/mol; and/or the number of the groups of groups,

the overall molecular weight distribution index of the polyglycolide material is 1.5-20.0, preferably 2.0-3.5; and/or the number of the groups of groups,

the melt flow rate of the polyglycolide material under the condition of 230 ℃/2.16kg is not higher than 20g/10min, preferably 1-10g/10min; and/or the number of the groups of groups,

the melt strength of the polyglycolide material at 235 ℃ is not less than 6cN, preferably not less than 8cN.

6. A process for preparing a polyglycolide material as claimed in any one of claims 1 to 5, comprising polymerizing a polyglycolide segmentIs co-introduced with a monomer, polyvinyl alcohol, and optionally a small moleculeAnd (3) a hair-growing agent, carrying out melt polymerization reaction in the presence of a catalyst, and cooling to obtain the polyglycolide material.

7. The method of manufacturing according to claim 6, wherein:

the monomer is selected from at least one of methyl glycolate, glycolic acid and glycolide, preferably glycolide; and/or the number of the groups of groups,

the alcoholysis degree of the polyvinyl alcohol is 68 to 99%, and/or the polymerization degree is 100 to 6000, preferably 300 to 2000.

8. The method of manufacturing according to claim 6, wherein:

the small molecule co-initiator is a small molecule substance with a boiling point of more than 160 ℃ and containing at least one functional group of a plurality of hydroxyl groups and amino groups; preferably, the method comprises the steps of,

the molecular weight of the small molecule co-initiator is less than 1000g/mol, preferably 60-300g/mol.

9. The method of manufacturing according to claim 6, wherein:

the catalyst is a salt compound or an organic guanidine catalyst corresponding to at least one of IIA-VA metal element and transition metal element;

preferably, the catalyst is a salt compound corresponding to at least one of Sn, bi, mg, al, ca, fe, mn, ti and Zn, and more preferably a Sn salt.

10. The method of manufacturing according to claim 6, wherein:

the preparation method further comprises the following steps: the melt polymerization reaction is carried out in the presence of an antioxidant; preferably, the method comprises the steps of,

the antioxidant is selected from hindered phenol antioxidants and/or phosphite antioxidants; and/or the number of the groups of groups,

the total amount of the antioxidant is 0 to 2 parts by mass, preferably 0.01 to 1 part by mass, per 100 parts by mass of the monomer.

11. The method of manufacturing according to claim 6, wherein:

the polyvinyl alcohol is used in an amount of 0.001 to 10 parts by mass, preferably 0.01 to 1 part by mass, relative to 100 parts by mass of the monomer; and/or the number of the groups of groups,

the small molecule co-initiator is used in an amount of 0.001 to 10 parts by mass, more preferably 0.01 to 1 part by mass, relative to 100 parts by mass of the monomer; and/or the number of the groups of groups,

the catalyst is used in an amount of 0.005 to 0.01 parts by mass, preferably 0.01 to 0.2 parts by mass, relative to 100 parts by mass of the monomer.

12. The preparation method according to one of claims 6 to 11, characterized in that:

the conditions for melt polymerization include: the temperature is 160-250deg.C, preferably 200-240 deg.C; the reaction time is 0.5-60min, preferably 1-10min; and/or the number of the groups of groups,

the melt polymerization reaction is carried out in a melt mixing device; preferably, the melt mixing device is one or more of a series combination of a kettle reactor, a tubular reactor, an internal mixer, a Farrel continuous mixer, a Banbury mixer, a single screw extruder, a multi-screw extruder and a reciprocating single screw extruder, preferably an internal mixer or a twin screw extruder; preferably, the method comprises the steps of,

the melt polymerization is carried out in a continuous twin-screw extrusion apparatus, preferably at a processing temperature of 180-250 ℃, preferably 210-240 ℃, a screw speed of 5-300rpm, preferably 40-150rpm, and an aspect ratio of 30-80, preferably 40-70.

13. The preparation method according to one of claims 6 to 12, characterized in that:

the melt polymerization reaction is carried out in at least two twin screw extrusion devices in series, preferably, the processing conditions of each twin screw extrusion device in series include:

14. A polyglycolide material prepared by the preparation method of any one of claims 6-13.