CN104086960B - A kind of polylactic acid composition and preparation method thereof - Google Patents
A kind of polylactic acid composition and preparation method thereof Download PDFInfo
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- CN104086960B CN104086960B CN201310110109.6A CN201310110109A CN104086960B CN 104086960 B CN104086960 B CN 104086960B CN 201310110109 A CN201310110109 A CN 201310110109A CN 104086960 B CN104086960 B CN 104086960B
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Abstract
The invention discloses polylactic acid composition, it is the melt blended material of following component: component a. star polylactic acid, its weight-average molecular weight 500 ~ 20000; Components b. linear polylactic acid, its weight-average molecular weight 10 ~ 400,000; And amount of component b. the multipolymer of alkene and unsaturated acid anhydride, described alkene is selected from C
1~ C
32alkene, its structural formula I is
Description
Technical field
The present invention relates to poly-lactic acid material field, be specifically related to a kind of polylactic acid composition with better toughness.The invention still further relates to the preparation method of above-mentioned polylactic acid composition.
Background technology
The production that synthesized polymer material is a large amount of and use create two key subjects: the environmental pollution that a large amount of consumption of limited petroleum resources and waste polymer cause.In this case, eco-friendly biodegradable material arises at the historic moment and obtains flourish.In numerous biodegradated polymer materal developed, poly(lactic acid) (PLA) with renewable resources plant for raw material, nontoxic, nonirritant, there is excellent biocompatibility, bioresorbable, completely biodegradability, also there is excellent physics, mechanical property simultaneously, thus paid close attention to more and more widely.But current commercialization polylactic acid melt intensity is low, fragility is high, toughness is not enough, elongation at break is low has become the key technical problem hindering poly(lactic acid) development and application.
Summary of the invention
For the deficiencies in the prior art, the invention provides a kind of polydactyl acid, the melt viscosity of described polydactyl acid is low, is easy to machine-shaping; Under the prerequisite ensureing poly(lactic acid) performance (as melt strength), this polydactyl acid has good toughness, has higher elongation at break.
According to an aspect of the present invention, provide a kind of polylactic acid composition, it is the melt blended material of following component:
Component a. star polylactic acid, its weight-average molecular weight 500 ~ 20000;
Components b. linear polylactic acid, its weight-average molecular weight 10 ~ 400,000; With
Amount of component b. the multipolymer of alkene and unsaturated acid anhydride, described alkene is selected from C1 ~ C32 alkene, and the structural formula I of described multipolymer is
In formula I formula, 1≤m≤30,1≤n≤100.
In above-mentioned polylactic acid composition, the amount of described component a star polylactic acid accounts for 2 ~ 20wt% of mixture total amount, preferably 2 ~ 10wt%.Described star (branching) poly(lactic acid) and linear polylactic acid consistency good, the decline of material property can not be caused in the course of processing.Described star polylactic acid add the melt viscosity that effectively can reduce described polylactic acid composition.
In a specific embodiment of above-mentioned polylactic acid composition, the alkene in described amount of component b is selected from C
6~ C
20, be preferably 1-octadecylene.The multipolymer of the side chain with long-chain branch that alkene and acid anhydrides are formed is conducive to the melt viscosity reducing polymkeric substance.
In a specific embodiment of above-mentioned polylactic acid composition, the unsaturated acid anhydride in described amount of component b is preferably maleic anhydride.The use of maleic anhydride is conducive to the performance improving poly(lactic acid), also can reduce the cost of polylactic acid composition simultaneously.
In above-mentioned polylactic acid composition, the mol ratio of the hydroxyl in described component a and the acid anhydrides in amount of component b is 1: 1 ~ 8.The having of unreacted anhydride bond is beneficial to the cross-linking density improving polylactic acid composition.
In above-mentioned polylactic acid composition, described star (branching) poly(lactic acid) and linear polylactic acid consistency good, the decline of material property can not be caused in the course of processing.Described star polylactic acid add the melt viscosity that effectively can reduce described polylactic acid composition, star polylactic acid and alkene (as 1-octadecylene) react with unsaturated acid anhydride (as maleic anhydride) multipolymer generation esterification and crosslinking simultaneously, the fragility of polylactic acid composition material can be improved, improve the toughness of polylactic acid composition material, improve the elongation at break of described polylactic acid composition.By regulating the content of each component, the polylactic acid composition that toughness is controlled can be obtained.
According to another aspect of the present invention, provide a kind of method preparing above-mentioned polylactic acid composition, comprise the following steps:
I under an inert atmosphere, lactide monomer catalyzer and containing at least two hydroxyls initiator effect under ring-opening polymerization obtain described star polylactic acid;
Alkene and unsaturated acid anhydride carry out being polymerized the multipolymer shown in the formula of obtaining I by II, and described alkene is selected from C
l~ C
32alkene, in formula I, 1≤m≤30,1≤n≤100;
Formula I
The described multipolymer that the star polylactic acid obtained in step I, step II obtain by III and linear polylactic acid carry out melt blending.
In the step I of aforesaid method, the molecular weight of star polylactic acid can be regulated and controled by the ratio changing monomer and catalyzer, and the arm number of star polymer can be regulated and controled by the initiator choosing different hydroxy number.Described initiator is selected from ethylene glycol, glycerol, erythritol, Xylitol, sorbic alcohol, tetramethylolmethane and dipentaerythritol.The mol ratio of described initiator and rac-Lactide is 1: 7.5 ~ 100.Described catalyzer is selected from the compound of glass putty, tin protochloride, stannous octoate, benzoic acid stannous, antimonous oxide, organic acid rare earth compound and iron, is preferably selected from stannous octoate and triisopropyl oxygen aluminium; The molar fraction that the add-on of described catalyzer accounts for rac-Lactide is 0.004 ~ 0.02%.Described rare gas element is as nitrogen, argon gas etc.
In aforesaid method specific embodiment, the concrete preparation process of described star polylactic acid is as follows: by rac-Lactide vacuum-drying 24 hours under 40oC: add initiator and dried rac-Lactide in the reaction vessel being connected with rare gas element, add catalyzer subsequently, stir and be heated to 120 ~ 180oC, react 2 ~ 5 hours, namely obtain star polylactic acid.Catalyzer is conventional rac-Lactide class monomer ring-opening polymerization catalyst, such as, be selected from the compound of glass putty, tin protochloride, stannous octoate, benzoic acid stannous, antimonous oxide, organic acid rare earth compound and iron; Described catalyzer also can be other sn-containing compound.When considering polymerization activity or product colour, be preferably selected from stannous octoate and triisopropyl oxygen aluminium.
In a specific embodiment of aforesaid method, the alkene in described amount of component b is selected from C
6~ C
20, preferred 1-octadecylene.Unsaturated acid anhydride in described amount of component b is preferably maleic anhydride.Alkene and acid anhydrides form the side chain multipolymer with long-chain branch, and being formed of side chain is beneficial to the melt viscosity reducing polymkeric substance.
In the above-mentioned methods, in described step III, the add-on of described star polylactic acid accounts for 2 ~ 20wt% of blend total mass, preferably 2 ~ 10wt%.Described star (branching) poly(lactic acid) and linear polylactic acid consistency good, the decline of material property can not be caused in the course of processing.Described star polylactic acid add the melt viscosity that effectively can reduce described polylactic acid composition.
In the above-mentioned methods, the mol ratio of the acid anhydrides of the hydroxyl in the star polylactic acid in step I and the multipolymer in step II is 1: 1 ~ 8.The having of unreacted anhydride bond is beneficial to the cross-linking density improving polylactic acid composition.
In the above-mentioned methods, the temperature of described melt blending is 150 ~ 200 DEG C, preferably 180 ~ 190 DEG C; The time of described melt blending is 3 ~ 10min, preferably 5 ~ 8min.
In a specific embodiment of aforesaid method, described melt blending preferably carries out in screw rod Banbury mixer.The screw speed of described screw rod Banbury mixer is 50 ~ 120 revs/min, is preferably 90 ~ 100 revs/min.
According to method provided by the invention, in melt blending process, crosslinking structure can be produced by reaction in－situ, multi-arm star poly(lactic acid) and described multipolymer is mixed in linear polyphosphazene polymer lactic acid, described star polylactic acid add the melt viscosity that effectively can reduce described polylactic acid composition, star polylactic acid and alkene (as 1-octadecylene) react with unsaturated acid anhydride (as maleic anhydride) multipolymer generation esterification and crosslinking simultaneously, the fragility of polylactic acid composition material can be improved, improve the toughness of polylactic acid composition material, improve the elongation at break of described polylactic acid composition.In addition, due to star polylactic acid and the good consistency of linear polylactic acid, the decline of material property can not be caused in the course of processing.By regulating the content of star polylactic acid and described multipolymer, the polylactic acid composition that toughness is controlled can be obtained.
According to the present invention, the toughness of the polylactic acid composition obtained is significantly improved, and has very high elongation at break; And by regulating the branched structure of star polylactic acid and the content of star polylactic acid and described multipolymer, can obtain the polylactic acid composition that toughness is controlled.。Simultaneously owing to not having small molecules to add in preparation process, star-branched poly(lactic acid) and line style poly(lactic acid) consistency good, can not cause the decline of material property in the course of processing, the polylactic acid composition obtained has higher performance.Star polylactic acid and described multipolymer, as the properties-correcting agent of poly(lactic acid), can reduce the melt viscosity of poly(lactic acid) while improving the fragility of poly(lactic acid), improve processing characteristics.
Embodiment
Below in conjunction with embodiment, the invention will be further described, but do not form any limitation of the invention.
Testing method:
Molecular weight and distribution thereof: Waters600E type liquid phase gel permeation chromatography (GPC) instrument of Waters company, moving phase is THF, and probe temperature is 35 DEG C.Polystyrene standard is adopted to carry out calibration curve mensuration.Mechanical characteristic is tested: batten overall length 50mm, width 4mm, testing length 2mm.Rate of extension 5mm/min, probe temperature 20 DEG C.
Embodiment 1:
In the reaction vessel being connected with rare gas element, add 12.7 grams of glycerol, 144 grams of dry L-rac-Lactides and 0.072 gram of stannous octoate respectively, stir and be heated to 160 DEG C, react 3 hours, be i.e. obtained star polylactic acid.Through gpc measurement number-average molecular weight 2100, molecular weight distribution 1.2.
The star polylactic acid of the linear polylactic acid of weight-average molecular weight 140,000 and above-mentioned preparation, 1-octadecylene are mixed with copolymer-maleic anhydride, the adding proportion (mass ratio) controlling star polylactic acid is respectively 2% and 10%, the hydroxyl of star polylactic acid and the anhydride molar ratio 1:2 of 1-octadecylene and copolymer-maleic anhydride.By said mixture melt blending in screw rod Banbury mixer, melt blending temperature is 185 DEG C, and the screw speed of Banbury mixer is 100rpm, and the melt blending time is 5 minutes.Sample is carried out mechanical stretching test, and elongation at break is respectively 10.3% and 27.6%.
Embodiment 2:
The preparation of star polylactic acid is with embodiment 1, and difference is to add 1.84 grams of glycerol, the number-average molecular weight 9700 of the star polylactic acid obtained.
The above-mentioned star polylactic acid prepared is prepared mixture by following steps.The preparation process of mixture is with embodiment 1, and difference is the hydroxyl of prepared star polylactic acid and the anhydride molar ratio 1:1 of 1-octadecylene and copolymer-maleic anhydride.Sample is carried out mechanical stretching test, and elongation at break is respectively 12.5% and 35.6%.
Data are in table 1.
Embodiment 3:
The preparation of star polylactic acid is with embodiment 1, and difference is to add 0.92 gram of glycerol, the number-average molecular weight 15300 of the star polylactic acid obtained, molecular weight distribution 1.3.
The above-mentioned star polylactic acid prepared is prepared mixture by following steps.The preparation process of mixture is with embodiment 1, and difference is the hydroxyl of prepared star polylactic acid and the anhydride molar ratio 1:1 of 1-octadecylene and copolymer-maleic anhydride.Sample is carried out mechanical stretching test, and elongation at break is respectively 9.7% and 30.6%.Data are in table 1.
Embodiment 4:
The preparation of star polylactic acid is with embodiment 1, and difference is to add 1.36 grams of tetramethylolmethanes, the number-average molecular weight 15700 of the star polylactic acid obtained, molecular weight distribution 1.3.
The above-mentioned star polylactic acid prepared is prepared mixture by following steps.The preparation process of mixture is with embodiment 1.Sample is carried out mechanical stretching test, and elongation at break is respectively 12.7% and 31.2%.
Data are in table 1.
Comparative example 1
The preparation of star polylactic acid is with embodiment 1, and difference is 1.84 grams of glycerol.Through the number-average molecular weight 9700 of the star polylactic acid that gpc measurement obtains, molecular weight distribution 1.2.
The star polylactic acid of the linear polylactic acid of weight-average molecular weight 140,000 with above-mentioned preparation is mixed, controls the adding proportion (mass ratio) 10% of star polylactic acid.By said mixture melt blending in screw rod Banbury mixer, melt blending temperature is 185oC, and the screw speed of Banbury mixer is 100rpm, and the melt blending time is 5 minutes.Sample is carried out mechanical stretching test, and elongation at break is 5.9%.
Data are in table 1.
Comparative example 2
By the melting in screw rod Banbury mixer of the linear polylactic acid of weight-average molecular weight 140,000, melt temperature is 185oC, and the screw speed of Banbury mixer is 100rpm, and the fusion time is 5 minutes.Sample is carried out mechanical stretching test, and elongation at break is 5.6%.
Data are in table 1.
Table 1 measuring mechanical property result
As can be seen from Table 1, according to the polylactic acid composition that the present invention obtains, there is higher mechanical property, while ensureing that composite materials has higher tensile strength, greatly can improve the toughness of material, as elongation at break, overcome the deficiency of conventional plasticising, flexibilizer additive polydactyl acid over-all properties.In addition, by regulating the branching arm number of star polylactic acid, the add-on of star polylactic acid and the ratio of star polylactic acid and maleic anhydride, the toughness of described composite materials can effectively be regulated.
It should be noted that above-described embodiment only for explaining the present invention, not forming any limitation of the invention.By referring to exemplary embodiments, invention has been described, but to should be understood to word wherein used be descriptive and explanatory vocabulary, instead of limited vocabulary.Can modify the present invention by the scope being defined in the claims in the present invention, and the present invention be revised not deviating from scope and spirit of the present invention.Although the present invention wherein described relates to specific method, material and embodiment, and do not mean that the present invention is limited to particular case disclosed in it, on the contrary, easily extensible of the present invention is to other all methods and applications with identical function.
Claims (15)
1. a polylactic acid composition, it is the melt blended material of following component:
Component a. star polylactic acid, its weight-average molecular weight 500 ~ 20000;
Components b. linear poly(lactic acid), its weight-average molecular weight 100,000 ~ 400,000; With
The multipolymer of amount of component b .1-octadecylene and maleic anhydride, the structural formula I of described multipolymer is
In formula, m is 16,1≤n≤100.
2. polylactic acid composition according to claim 1, is characterized in that, the amount of described component a star polylactic acid accounts for 2 ~ 20wt% of mixture total amount.
3. polylactic acid composition according to claim 2, is characterized in that, the amount of described component a star polylactic acid accounts for 2 ~ 10wt% of mixture total amount.
4. according to the polylactic acid composition in claims 1 to 3 described in any one, it is characterized in that, the mol ratio of the hydroxyl in described component a and the acid anhydrides in amount of component b is 1:(1 ~ 8).
5. prepare a method for polylactic acid composition described in any one in Claims 1 to 4, comprise the following steps:
I under an inert atmosphere, lactide monomer catalyzer and containing at least two hydroxyls initiator effect under ring-opening polymerization obtain described star polylactic acid, described initiator is selected from least one in ethylene glycol, glycerol, erythritol, Xylitol, sorbic alcohol, tetramethylolmethane and dipentaerythritol;
1-octadecylene and maleic anhydride carry out being polymerized the multipolymer shown in the formula of obtaining I by II, and in formula I, m is 16,1≤n≤100;
The described multipolymer that the star polylactic acid obtained in step I, step II obtain by III and linear poly(lactic acid) carry out melt blending.
6. method according to claim 5, is characterized in that, the mol ratio of described initiator and rac-Lactide is 1:(7.5 ~ 100).
7. method according to claim 5, is characterized in that, described catalyzer is selected from least one in the compound of glass putty, tin protochloride, stannous octoate, benzoic acid stannous, antimonous oxide, organic acid rare earth compound and iron; The molar fraction that the add-on of described catalyzer accounts for rac-Lactide is 0.004 ~ 0.02%.
8. method according to claim 5, is characterized in that, described catalyzer is selected from stannous octoate and triisopropyl oxygen aluminium; The molar fraction that the add-on of described catalyzer accounts for rac-Lactide is 0.004 ~ 0.02%.
9. method according to claim 5, is characterized in that, in described step III, the add-on of described star polylactic acid accounts for 2 ~ 20wt% of blend total mass.
10. method according to claim 9, is characterized in that, in described step III, the add-on of described star polylactic acid accounts for 2 ~ 10wt% of blend total mass.
11. methods according to claim 5, is characterized in that, the mol ratio of the acid anhydrides of the multipolymer in the hydroxyl in the star polylactic acid in step I and step II is 1:(1 ~ 8).
12., according to the method in claim 5 ~ 11 described in any one, is characterized in that, the temperature of described melt blending is 150 ~ 200 DEG C; The time of described melt blending is 3 ~ 10min.
13. methods according to claim 12, is characterized in that, the temperature of described melt blending is 180 ~ 190 DEG C; The time of described melt blending is 5 ~ 8min.
14., according to the method in claim 5 ~ 11 described in any one, is characterized in that, described melt blending carries out in screw rod Banbury mixer, and the screw speed of described screw rod Banbury mixer is 50 ~ 120 revs/min.
15. methods according to claim 14, is characterized in that, the screw speed of described screw rod Banbury mixer is 90 ~ 100 revs/min.
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| CN105086392B (en) * | 2014-05-08 | 2017-05-31 | 中国石油化工股份有限公司 | A kind of polydactyl acid and preparation method thereof |
| CN106280326B (en) * | 2015-06-03 | 2018-09-21 | 中国石油化工股份有限公司 | A kind of lactic acid composite material and preparation method and application |
| CN109206865B (en) * | 2017-07-03 | 2023-01-03 | 中国石油化工股份有限公司 | Phosphorus-containing copolymerized flame-retardant polylactic acid and preparation method thereof |
| CN114773581A (en) * | 2022-04-25 | 2022-07-22 | 万华化学集团股份有限公司 | Polylactic acid composition and preparation method thereof |
| CN114940745A (en) * | 2022-06-09 | 2022-08-26 | 万华化学集团股份有限公司 | Preparation method of polylactic acid with controllable molecular weight |
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