CN113956486B - Long-chain branch polylactic acid-based copolymer and preparation method thereof - Google Patents
Long-chain branch polylactic acid-based copolymer and preparation method thereof Download PDFInfo
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- C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
- C08G81/00—Macromolecular compounds obtained by interreacting polymers in the absence of monomers, e.g. block polymers
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- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
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- C08G63/00—Macromolecular compounds obtained by reactions forming a carboxylic ester link in the main chain of the macromolecule
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- C08G63/912—Polymers modified by chemical after-treatment derived from hydroxycarboxylic acids
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- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
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- Y02W—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT
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Abstract
The invention provides a preparation method of a long-chain branched polylactic acid-based copolymer, which comprises the following steps: reacting monohydroxy polylactic acid with phthalic acid dianhydride to obtain dicarboxy polylactic acid; then reacting the hydroxyl polylactic acid with a monoepoxy compound to obtain dihydroxy polylactic acid; and finally, carrying out chain extension on the polylactic acid copolymer and polyester under the action of a chain extender to obtain the long-chain branched polylactic acid based copolymer with the main chain being a flexible chain segment and the side chain being polylactic acid. In the polylactic acid-based copolymer prepared by the method, the copolymer has good flexibility and high mechanical property; the polymer has long-chain branches, so that the melt strength of the copolymer can be effectively adjusted; the copolymer has high molecular weight and can directly replace various current plastic product raw materials; low preparation cost and good biodegradability. The invention also provides a long-chain branched polylactic acid-based copolymer.
Description
Technical Field
The invention belongs to the field of high polymer materials, and particularly relates to a long-chain branched polylactic acid-based copolymer and a preparation method thereof.
Background
The plastic packaging is simple and convenient, but the plastic packaging materials used in large quantity at present are all non-degradable plastics, which causes serious problems of resource shortage, environmental pollution and the like. The biodegradable plastics industry is the most effective way to solve this problem. The polylactic acid has excellent biodegradability, and can be completely degraded by microorganisms in soil to generate CO in one year after being discarded2And water, and no pollution is caused to the environment. However, polylactic acid contains a large amount of ester bonds, has poor hydrophilicity, reduces the compatibility of the polylactic acid with other substances, and has high brittleness, poor impact resistance and low melt strength, thereby limiting the wide application of the polylactic acid.
In view of the above-mentioned disadvantages of polylactic acid, many researchers have conducted extensive studies on modification of polylactic acid in recent years. The chain extension method has the advantages of simple process, short reaction time and the like, and has great advantage in reducing the production cost. However, the copolymer obtained by the chain extension reaction in the prior art is of a linear structure, the melt strength of the product cannot be effectively improved, and the application in the fields of films and the like is difficult. In addition, the prior art has difficulty in obtaining a polylactic acid copolymer with high molecular weight, thereby limiting the application thereof.
Therefore, how to prepare the polylactic acid-based copolymer by a simple, effective and low-cost method, and simultaneously, the preparation method can meet the requirements of high melt strength and high molecular weight and can meet the application requirements in the fields of film blowing, injection molding processing and the like, and has very important social and economic values.
Disclosure of Invention
In view of the above, the present invention aims to provide a long-chain branched polylactic acid-based copolymer having a main chain as a flexible segment and a side chain as polylactic acid, and the long-chain branched polylactic acid-based copolymer provided by the present invention has the advantages of good flexibility, high molecular weight, low toxicity, simplicity, effectiveness and contribution to industrial production.
The invention provides a long-chain branched polylactic acid-based copolymer, which comprises the following components in part by weight: formula I and/or formula II:
in the formula I, R is CH3-(CH2)q-，q＝0～21；
n＝150～600；
V is- (CH)2)i-，i＝2～10；
T is- (CH)2)t-，t＝1～8；
S is the residual group of diisocyanate after removing isocyanate group;
m＝5～20；
in the formula II, R is CH3-(CH2)q-，q＝0～21，
n＝150～600；
V is- (CH)2)i-，i＝2～10；
T is- (CH)2)t-，t＝1～8；
S is the residual group of diisocyanate after removing isocyanate group;
m＝5～20。
the invention provides a preparation method of a long-chain branched polylactic acid-based copolymer, which comprises the following steps:
carrying out a first reaction on monohydroxy polylactic acid and phthalic tetracarboxylic dianhydride to obtain dicarboxyl polylactic acid;
carrying out a second reaction on the mono-epoxy polymer and the bi-carboxyl polylactic acid to obtain bi-hydroxyl polylactic acid;
and carrying out chain extension reaction on the polyester and the dihydroxy polylactic acid under the action of a chain extender to obtain the long-chain branched polylactic acid based copolymer with the main chain being the polyester and the side chain being the polylactic acid.
Preferably, the temperature of the first reaction is 150-220 ℃;
the time of the first reaction is 20 min-10 h.
Preferably, the temperature of the second reaction is 150-200 ℃;
the time of the second reaction is 20 min-5 h.
Preferably, the temperature of the chain extension reaction is 160-220 ℃;
the time of the chain extension reaction is 8-60 min.
Preferably, the mass ratio of the monohydroxypolylactic acid to the pyromellitic dianhydride is (2-4): 1;
the mass ratio of the monoepoxy polymer to the dicarboxy polylactic acid is (2-4): 1;
the mass ratio of the polyester to the dihydroxy polylactic acid is (1-9): (9-1);
the mass of the chain extender is 1-10% of the total mass of the polyester and the dihydroxy polylactic acid.
Preferably, the monohydroxy polylactic acid is selected from one or more of levorotatory polylactic acid and dextrorotatory polylactic acid.
Preferably, the monoepoxy compound is selected from one or more of propylene oxide, styrene oxide, allyl glycidyl ether, phenyl glycidyl ether, methyl propylene oxide, cis-2, 3-butylene oxide, 2-toluene glycidyl ether, (2-methoxyphenoxy) methyl ethylene oxide, n-butyl glycidyl ether, 1, 2-epoxydodecane, 1, 2-epoxyoctadecane, 4-methoxyphenylethylene oxide, epoxypropyl methyl ether and glycidyl methacrylate.
Preferably, the chain extender is one or more selected from acid anhydride substances, heterocyclic substances, isocyanate substances, binary acid chloride substances, trimethyl trimellitate and triphenyl phosphite.
Preferably, the number average molecular weight of the polylactic acid is 1 to 5 ten thousand; the melting point is 150-180 ℃.
The invention tests the mechanical property of the prepared long-chain branched polylactic acid-based copolymer, and the specific process is as follows: the polylactic acid based copolymer with a long chain branch of 70mm × 4mm × 1mm was placed on a tensile tester to perform tensile property test at a tensile rate of 20mm/min and a test temperature of 23 ℃, and the elongation at break of the polylactic acid resin was recorded. The test result shows that: the breaking elongation of the long-chain branched polylactic acid-based copolymer provided by the invention is up to 650%.
The invention tests the melt strength of the prepared long-chain branched polylactic acid-based copolymer, and the specific process is as follows: a sample of a long chain branched polylactic acid based copolymer having a thickness of 1mm and a diameter of 25mm was placed in a rotational rheometer to be subjected to a melt strength test, a dynamic frequency strain was 5%, an angular frequency was swept from 0.1rad/s to 100rad/s, and a change in complex viscosity (. Eta.) with frequency was recorded. The test result shows that: the complex viscosity of the long-chain branched polylactic acid-based copolymer provided by the invention is higher than that of polylactic acid/PBAT blended resin in the whole shear frequency range.
Compared with the existing polylactic acid-polyester copolymer, in the polylactic acid-based copolymer prepared by the method provided by the invention, polylactic acid is introduced into the copolymer in a side chain manner, and the main chain is a flexible polyester chain segment copolymer, so that the flexibility is good, and the mechanical property is high; the polylactic acid-based copolymer prepared by the method has controllable branched chain length and controllable number, can effectively adjust the melt strength of the copolymer, and solves the problems that the existing polylactic acid-based copolymer has low melt strength and is difficult to accurately adjust; the polylactic acid-based copolymer provided by the invention breaks through the traditional preparation method of the polylactic acid copolymer, the melt index of the prepared polylactic acid-based copolymer exceeds that of polylactic acid and polyester, and the polylactic acid-based copolymer can directly replace various current plastic product raw materials. The components adopted in the process of preparing the polylactic acid-based copolymer are degradable substances, so that the preparation cost is low and the polylactic acid-based copolymer has good biodegradability. The long-chain branched polylactic acid-based copolymer prepared by the invention has the advantages of good flexibility, high molecular weight, small toxicity, simplicity, effectiveness and contribution to industrial production. In addition, the invention can adopt a one-pot method for synthesis, the process is more simplified, and the cost is greatly reduced.
Drawings
FIG. 1 is a stress-strain curve of a polylactic acid-based copolymer prepared according to example 1 of the present invention;
fig. 2 is a rheological curve of the polylactic acid-based copolymer prepared in example 1 of the present invention.
Detailed Description
The technical solutions in the embodiments of the present invention will be described clearly and completely below, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other examples, which may be modified or appreciated by those of ordinary skill in the art based on the examples given herein, are intended to be within the scope of the present invention. It should be understood that the embodiments of the present invention are only for illustrating the technical effects of the present invention, and are not intended to limit the scope of the present invention. In the examples, the methods used were all conventional methods unless otherwise specified.
The invention provides a long-chain branched polylactic acid-based copolymer, which comprises the following components in part by weight: formula I and/or formula II:
in the formula I, R is CH3-(CH2)q-，q＝0～21；
n＝150～600；
V is- (CH)2)i-，i＝2～10；
T is- (CH)2)t-，t＝1～8；
S is the residual group of diisocyanate after removing isocyanate group;
m＝5～20；
in the formula II, R is CH3-(CH2)q-，q＝0～21，
n＝150～600；
V is- (CH)2)i-，i＝2～10；
T is- (CH)2)t-，t＝1～8；
S is the residual group of diisocyanate after removing isocyanate group;
m＝5～20。
in the present invention, in the formula I, q is preferably 5 to 15, more preferably 8 to 12, and most preferably 10; n is preferably from 200 to 500, more preferably from 300 to 400, most preferably 350; i is preferably from 3 to 8, more preferably from 4 to 6, most preferably 5; t is preferably 2 to 6, more preferably 3 to 5, most preferably 4; m is preferably 10 to 15, more preferably 12 to 13.
In the present invention, in the formula II, q is preferably 5 to 15, more preferably 8 to 12, and most preferably 10; n is preferably from 200 to 500, more preferably from 300 to 400, most preferably 350; i is preferably from 3 to 8, more preferably from 4 to 6, most preferably 5; t is preferably 2 to 6, more preferably 3 to 5, most preferably 4; m is preferably 10 to 15, more preferably 12 to 13.
The invention provides a preparation method of a long-chain branched polylactic acid-based copolymer, which comprises the following steps:
carrying out a first reaction on monohydroxy polylactic acid and phthalic tetracarboxylic dianhydride to obtain dicarboxyl polylactic acid;
carrying out a second reaction on the mono-epoxy polymer and the bi-carboxyl polylactic acid to obtain bi-hydroxyl polylactic acid;
and carrying out chain extension reaction on the polyester and the dihydroxy polylactic acid under the action of a chain extender to obtain the long-chain branched polylactic acid based copolymer with the main chain being the polyester and the side chain being the polylactic acid.
In the invention, the monohydroxy polylactic acid is preferably one or more of levorotatory polylactic acid and dextrorotatory polylactic acid.
In the present invention, the number average molecular weight of the monohydroxypolylactic acid is preferably 1 to 5 ten thousand, more preferably 2 to 4 ten thousand, and most preferably 3 ten thousand; the melting point is preferably 150 to 180 ℃, more preferably 160 to 170 ℃, most preferably 165 ℃.
The monohydroxy polylactic acid used in the present invention is not particularly limited, and a monohydroxy polylactic acid known to those skilled in the art may be used, and the monohydroxy polylactic acid may be a commercially available product or may be prepared by a method known to those skilled in the art for producing polylactic acid.
In the present invention, the ratio of the amounts of the monohydroxypolylactic acid to phthalic dianhydride is preferably (2 to 4): 1, more preferably (2.5 to 3.5): 1, most preferably 3:1.
in the present invention, the temperature of the first reaction is preferably 150 to 220 ℃, more preferably 160 to 210 ℃, more preferably 170 to 200 ℃, and most preferably 180 to 190 ℃; the time for the first reaction is preferably 0.5 to 10 hours, more preferably 1 to 8 hours, more preferably 2 to 6 hours, and most preferably 3 to 5 hours.
In the present invention, the monoepoxy compound is preferably selected from one or more of propylene oxide, styrene oxide, allyl glycidyl ether, phenyl glycidyl ether, methyl propylene oxide, cis-2, 3-butylene oxide, 2-toluene glycidyl ether, (2-methoxyphenoxy) methyl ethylene oxide, n-butyl glycidyl ether, 1, 2-epoxydodecane, 1, 2-epoxyoctadecane, 4-methoxyphenylethylene oxide, epoxypropyl methyl ether and glycidyl methacrylate.
In the present invention, the ratio of the amounts of the substance of the monoepoxy polymer and the biscarboxy polylactic acid is preferably (2 to 4): 1, more preferably (2.5 to 3.5): 1, most preferably 3:1.
in the present invention, the temperature of the second reaction is preferably 150 to 200 ℃, more preferably 160 to 190 ℃, and most preferably 170 to 180 ℃; the time for the second reaction is preferably 0.5 to 5 hours, more preferably 1 to 4 hours, and most preferably 2 to 3 hours.
In the present invention, the polyester is preferably one or more of aliphatic polyester and aliphatic-aromatic polyester, and more preferably one or more selected from polybutylene succinate, polyethylene succinate, polyhexamethylene succinate, polyethylene adipate, polybutylene adipate, polyhexamethylene adipate, polyethylene sebacate, polybutylene sebacate, polyhexamethylene sebacate, poly (ethylene succinate-co-ethylene terephthalate), poly (butylene succinate-co-butylene terephthalate), poly (ethylene succinate-co-ethylene terephthalate), poly (ethylene adipate-co-ethylene terephthalate), poly (butylene adipate-co-ethylene terephthalate), poly (ethylene sebacate-co-ethylene terephthalate), poly (sebacate-co-butylene terephthalate), and poly (adipate-co-ethylene terephthalate).
In the present invention, the number average molecular weight of the polyester is preferably 1 to 5 ten thousand, more preferably 2 to 4 ten thousand, and most preferably 3 ten thousand; the melting point is preferably from 100 to 150 deg.C, more preferably from 110 to 140 deg.C, most preferably from 120 to 130 deg.C.
The preparation method of the polyester is not particularly limited in the invention, and the polyester can be prepared by adopting the preparation method of the polyester well known to the technical personnel in the field.
In the invention, the chain extender is preferably one or more selected from acid anhydride substances, heterocyclic substances, isocyanate substances, binary acyl chloride substances, trimethyl trimellitate and triphenyl phosphite.
In the present invention, the isocyanate-based substance is preferably a diisocyanate-based substance; <xnotran> , ,4,4' - ( ), -2,4- , , , ,4,4- , ,1,3- -2- ,1,3- ,1,8- -4- ( ) ,1,3- ,2,4- -1- - ,2,6- , -1,4- , -2,4- , -1,2- ,1,4- ,4,4- -3,3- , -1,4- ,1,12- , -1,6- , ,1,6- ,1,5- -2- ,3,3- 4,4- . </xnotran>
In the present invention, the mass ratio of the polyester to the bishydroxy polylactic acid is preferably (1 to 9): (9-1), more preferably (2-6): (6-2), most preferably (3-5): (5-3).
In the present invention, the mass of the chain extender is preferably 1 to 10%, more preferably 2 to 8%, more preferably 3 to 6%, and most preferably 4 to 5% of the total mass of the polyester and the bishydroxypolylactic acid.
In the invention, the temperature of the chain extension reaction is preferably 160-220 ℃, more preferably 170-210 ℃, more preferably 180-200 ℃, and most preferably 190 ℃; the time of the chain extension reaction is preferably 8min to 2 hours, more preferably 15min to 1.5 hours, more preferably 0.5 hours to 1 hour, and most preferably 0.6 to 0.8 hour.
In the present invention, the first reaction, the second reaction, and the chain extension reaction are preferably performed in a reaction kettle, an internal mixer, or an extruder.
In the present invention, after the chain extension reaction is completed, the method preferably further comprises:
and carrying out hot-press molding on the obtained reaction product.
The present invention is not particularly limited to the specific method of hot press molding, and a hot press method known to those skilled in the art may be used.
In the invention, the hot-press molding temperature is preferably 170-230 ℃, more preferably 180-220 ℃, more preferably 190-210 ℃, and most preferably 200 ℃; the pressure for the hot press molding is preferably 8 to 20MPa, more preferably 10 to 15MPa, and most preferably 12 to 13MPa.
Compared with the prior art for preparing the polylactic acid-polyester copolymer, in the polylactic acid-based copolymer prepared by the method provided by the invention, the polylactic acid is introduced into the copolymer in a side chain mode, and the main chain is a flexible polyester chain segment, so that the copolymer has good flexibility and high mechanical property; the polylactic acid-based copolymer prepared by the invention has controllable branched chain length and controllable number, can effectively adjust the melt strength of the copolymer, and solves the problems that the melt strength of the existing polylactic acid copolymer is low and is difficult to accurately adjust; the method for preparing the polylactic acid-based copolymer breaks through the traditional preparation method of the polylactic acid-based copolymer, the melt index of the prepared polylactic acid-based copolymer exceeds the melt index of polylactic acid and polyester, and the polylactic acid-based copolymer can directly replace various current plastic product raw materials; the components used in the invention are all degradable substances, the preparation cost is low, and the biological degradability is good. The long-chain branched polylactic acid-based copolymer prepared by the invention has the advantages of good flexibility, high molecular weight, small toxicity, simplicity, effectiveness and contribution to industrial production. In addition, the invention can adopt a one-pot method for synthesis, so that the process is simplified, and the cost is greatly reduced.
Example 1
1.1 after 1140g of terephthalic acid, 1340g of adipic acid, 3000g of butanediol and 5g of tetrabutyl titanate are sequentially added into a flask, the temperature is quickly raised to 190 ℃ until no liquid is distilled off in the reaction, the temperature is raised to 240 ℃, and the polycondensation reaction is carried out by vacuumizing for 6 hours under the pressure of 500Pa to obtain the poly (butylene adipate-co-butylene terephthalate) copolymer with the number-average molecular weight of 1.5 ten thousand.
1.2 repeatedly vacuumizing and filling nitrogen to cool a 3L round-bottom flask with a branch pipe, filling nitrogen, adding 6g of isopropanol, 1440g of levorotatory lactide and 2g of stannous octoate, reacting at 130 ℃, after 15 hours of reaction, heating to 180 ℃, vacuumizing to remove unreacted monomers, wherein the pressure is 100Pa, and obtaining the monohydroxy polylactic acid with the number average molecular weight of 1.6 ten thousand.
1.3 reacting 160g of the 1.2 monohydroxy polylactic acid with 1.09g of pyromellitic dianhydride at 180 ℃, stirring the reactants, adding 1.2g of styrene oxide after reacting for 1 hour, and continuously stirring for 1 hour to obtain dihydroxy polylactic acid; then 150g of the poly (butylene adipate-co-butylene terephthalate) copolymer in 1.1 and 6g of hexamethylene diisocyanate are added and stirred for 20min to obtain a long-chain branched polylactic acid-based copolymer, and the measured melt index of the copolymer is 3g/10min; hot pressing the mixture on a flat vulcanizing machine to obtain a sheet, wherein the hot pressing temperature is 200 ℃, and the pressure is 12MPa, so that a sheet with the thickness of 1.0mm is obtained.
1.4 mixing 1kg of PBAT (Jinfa technology, melt index: 4.2g/10 min) and 1kg of polylactic acid (Haizheng biomaterial, melt index: 4g/10 min) in a twin-screw extruder; the mixing temperature is 210 ℃, the mixing time is 10min, and the polylactic acid/PBAT blend resin is obtained.
Mechanical property tests are performed on the product prepared in 1.3 and the product prepared in 1.4 according to the above method, and the test results show that the breaking elongation of the long-chain branched polylactic acid-based copolymer prepared in example 1 of the present invention is shown in fig. 1, and fig. 1 shows the stress-strain curves of the polylactic acid/PBAT blend resin and the long-chain branched polylactic acid-based copolymer prepared in example 1 of the present invention, wherein a is the stress-strain curve of the polylactic acid/PBAT blend resin, and b is the stress-strain curve of the long-chain branched polylactic acid-based copolymer obtained in example 1 of the present invention; as can be seen from fig. 1, the elongation at break of the long-chain branched polylactic acid-based copolymer obtained in example 1 of the present invention was 640%.
According to the method, the long-chain branched polylactic acid-based copolymer prepared in the embodiment 1 of the invention is subjected to rheological test analysis, and a complex viscosity curve of the long-chain branched polylactic acid-based copolymer along with frequency change is obtained, as shown in fig. 2, wherein a curve a is a rheological curve of polylactic acid/PBAT blend resin, and a curve b is a rheological curve of the long-chain branched polylactic acid-based copolymer prepared in the embodiment 1 of the invention; in comparison with curve a, the complex viscosity of curve b is much greater than that of curve a throughout the entire shear frequency range, indicating that the polylactic acid-based copolymer prepared in example 1 of the present invention has a structure of long chain branches.
The structural formula of the product prepared in example 1 of the invention is as follows:
example 2
2.1 adding 1140g terephthalic acid, 1340g adipic acid, 2000g ethylene glycol and 5g tetrabutyl titanate into a flask in sequence, then rapidly heating to 180 ℃ until no liquid is distilled out, heating to 240 ℃, vacuumizing to perform polycondensation reaction, wherein the pressure is 500Pa,7h, and then obtaining the poly (ethylene adipate-co-ethylene terephthalate) copolymer with the number average molecular weight of 1.7 ten thousand.
2.2 reacting 200g of the monohydroxypolylactic acid prepared in 1.2 of example 1 with 1.09g of pyromellitic dianhydride at 170 ℃ with stirring, adding 1.3g of allyl glycidyl ether after 2 hours of reaction, and continuing stirring to obtain dihydroxy polylactic acid after 2 hours; then 150g of poly (ethylene adipate-co-ethylene terephthalate) in 2.1 and 6g of hexamethylene diisocyanate are added and stirred for 15min to obtain a long-chain branched polylactic acid-based copolymer, and the measured melt index of the copolymer is 3.5g/10min; hot pressing the sheet material on a flat vulcanizing machine at 200 ℃ and 10MPa to obtain a sheet material with the thickness of 1.0 mm.
The product prepared in example 2 of the present invention was tested according to the above method, and as a result, the elongation at break of the long chain branched polylactic acid based copolymer prepared in example 2 of the present invention was 520%.
Rheological test analysis is carried out on the long-chain branched polylactic acid-based copolymer prepared in the embodiment 2 of the invention, and the result shows that: at an angular frequency of 0.1rad/s, the complex viscosity is 8.8 x 104Pa.S; the complex viscosity of the polylactic acid-based copolymer was 2700pa.s at an angular frequency of 100rad/s, and was higher than that of the polylactic acid/PBAT blend resin in example 1 throughout the entire shear frequency range, indicating that the polylactic acid-based copolymer prepared in example 2 of the present invention has a structure of long chain branches.
Example 3
3.1 adding 1140g terephthalic acid, 1340g adipic acid, 4000g hexanediol and 7g tetrabutyl titanate into a flask in sequence, rapidly heating to 190 ℃ until no liquid is distilled out, heating to 240 ℃, vacuumizing to perform polycondensation reaction under 500Pa and 7h to obtain poly (adipic acid hexanediol-co-terephthalic acid hexanediol) copolymer with the number average molecular weight of 1.8 ten thousand.
3.2 160g of the monohydroxy polylactic acid prepared in 1.2 of the example 1 and 1.09g of pyromellitic dianhydride are reacted at 180 ℃, the reactants are stirred, after 2 hours of reaction, 1.8g of phenyl glycidyl ether is added, stirring is continued, and after 1 hour, the dihydroxy polylactic acid is obtained; then 200g of poly (hexanediol adipate-co-hexanediol terephthalate) in 3.1 and 8g of p-phenylene diisocyanate are added and stirred for 30min to obtain a long-chain branched polylactic acid-based copolymer, and the measured melt index of the copolymer is 2g/10min; hot pressing the sheet material on a flat vulcanizing machine at 190 ℃ and 12MPa to obtain a sheet material with the thickness of 1.0 mm.
According to the method of the above technical scheme, the product prepared in the embodiment 3 of the present invention is tested, and the test result shows that the elongation at break of the long chain branched polylactic acid based copolymer prepared in the embodiment 3 of the present invention is 650%.
Rheological test analysis is carried out on the long-chain branched polylactic acid-based copolymer prepared in the embodiment 3 of the invention, and the result shows that: the complex viscosity is 1.5 x 10 at an angular frequency of 0.1rad/s5Pa.S; the complex viscosity of the polylactic acid-based copolymer was 3200pa.s at an angular frequency of 100rad/s, and was higher than that of the rheological curve of the polylactic acid/PBAT blend resin in example 1 throughout the entire shear frequency range, indicating that the polylactic acid-based copolymer prepared in example 3 of the present invention has a structure of a long chain branch.
Example 4
4.1 after 1140g of terephthalic acid, 1000g of succinic acid, 3000g of butanediol and 5g of tetrabutyl titanate are sequentially added into a flask, the temperature is rapidly raised to 190 ℃ until no liquid is distilled off in the reaction, the temperature is raised to 240 ℃, and the polycondensation reaction is carried out by vacuumizing under the pressure of 500Pa for 8h, thus obtaining the poly (butylene succinate-co-butylene terephthalate) copolymer with the number average molecular weight of 1.7 ten thousand.
4.2 repeatedly vacuumizing and filling nitrogen to cool a 3L round-bottom flask with a branch pipe, filling nitrogen, adding 5g of isopropanol, 1440g of levorotatory lactide and 3g of stannous octoate, reacting at 130 ℃, heating to 180 ℃ after 20 hours of reaction, vacuumizing to remove unreacted monomers, and obtaining the monohydroxy polylactic acid with the number average molecular weight of 1.8 ten thousand, wherein the pressure is 100Pa.
4.3 reacting 200g of monohydroxy polylactic acid in 4.2 with 1.09g of pyromellitic dianhydride at the temperature of 170 ℃, stirring the reactants, adding 1.8g of 2-toluene glycidyl ether after reacting for 3h, and continuing stirring to obtain dihydroxy polylactic acid after 2 h; then adding 100g of poly (butylene succinate-co-butylene terephthalate) in 4.1 and 6g of p-phenylene diisocyanate, and stirring for 30min to obtain a long-chain branched polylactic acid-based copolymer, wherein the measured melt index of the copolymer is 2.2g/10min; hot pressing the sheet material on a flat vulcanizing machine at 190 ℃ and 10MPa to obtain a sheet material with the thickness of 1.0 mm.
According to the method of the technical scheme, the product prepared in the invention in the embodiment 4 is tested, and the test result shows that the breaking elongation of the long-chain branched polylactic acid-based copolymer prepared in the invention in the embodiment 4 is 505%.
Rheological test analysis is carried out on the long-chain branched polylactic acid-based copolymer prepared in the embodiment 4 of the invention, and the result shows that: complex viscosity of 7.5 x 10 at an angular frequency of 0.1rad/s4Pa.S; the complex viscosity of the polylactic acid-based copolymer was higher than that of the polylactic acid/PBAT blend resin in example 1 throughout the shear frequency range at an angular frequency of 100rad/s of 2600pa.s, indicating that the polylactic acid-based copolymer prepared in example 4 of the present invention has a structure of long chain branches.
Example 5
5.1 adding 1320g dimethyl terephthalate, 1000g succinic acid, 2200g ethylene glycol and 10g tetrabutyl titanate into a flask in sequence, then rapidly heating to 180 ℃ until no liquid is distilled off in the reaction, heating to 240 ℃, vacuumizing for polycondensation reaction, wherein the pressure is 500Pa, and the number average molecular weight is 1.5 ten thousand, thus obtaining the poly (ethylene succinate-co-ethylene terephthalate) copolymer.
5.2 reacting 200g of monohydroxypolylactic acid prepared in 4.2 of example 4 with 1.09g of pyromellitic dianhydride at 180 ℃, stirring the reaction product, adding 1.6g of 4-methoxyphenyl ethylene oxide after reacting for 30min, and continuing stirring for 40min to obtain dihydroxypolylactic acid; then 150g of 5.1 poly (ethylene succinate-co-ethylene terephthalate) and 10g of toluene-2, 4-diisocyanate were added and stirred for 25min to obtain a long-chain branched polylactic acid based copolymer, and the melt index of the copolymer was measured to be 2.3g/10min; hot pressing the mixture on a flat vulcanizing machine to obtain a sheet, wherein the hot pressing temperature is 190 ℃, and the pressure is 10MPa, so that a sheet with the thickness of 1.0mm is obtained.
According to the method of the technical scheme, the product prepared in the invention in the embodiment 5 is detected, and the detection result shows that the breaking elongation of the long chain branched polylactic acid-based copolymer prepared in the embodiment 5 is 560%.
Rheological test analysis is carried out on the long-chain branched polylactic acid-based copolymer prepared in the embodiment 5 of the invention, and the result shows that: the complex viscosity at an angular frequency of 0.1rad/s is 2.8 x 105Pa.S; the complex viscosity of the polylactic acid-based copolymer was 3400pa.s at an angular frequency of 100rad/s, and was higher than that of the polylactic acid/PBAT blend resin in example 1 over the entire shear frequency range, indicating that the polylactic acid-based copolymer prepared in example 5 of the present invention has a structure of long chain branches.
Example 6
6.1 after 1320g dimethyl terephthalate, 1000g succinic acid, 4000g hexanediol and 8g tetrabutyl titanate are added into a flask in sequence, the temperature is rapidly raised to 180 ℃ until no liquid is distilled off in the reaction, the temperature is raised to 240 ℃, and the polycondensation reaction is carried out by vacuumizing, wherein the pressure is 500Pa, and the number average molecular weight is 1.8 ten thousand, so that the poly (hexanediol succinate-co-hexanediol terephthalate) copolymer is obtained.
6.2 reacting 220g of monohydroxy polylactic acid prepared by 4.2 in the example 4 with 1.09g of pyromellitic dianhydride at 200 ℃, stirring the reactants, adding 1.5g of glycidyl methacrylate after reacting for 30min, continuing stirring, and obtaining dihydroxy polylactic acid after 30 min; then 150g of poly (hexamethylene succinate-co-hexamethylene terephthalate) in 6.1 and 6g of toluene-2, 4-diisocyanate are added and stirred for 10min to obtain a long-chain branched polylactic acid-based copolymer, and the measured melt index of the copolymer is 2g/10min; hot pressing the sheet material on a flat vulcanizing machine at 200 ℃ and 10MPa to obtain a sheet material with the thickness of 1.0 mm.
When the product prepared in example 6 of the present invention is detected according to the method of the above technical scheme, the detection result indicates that the elongation at break of the long-chain branched polylactic acid-based copolymer obtained in example 6 of the present invention is 650%.
For the long-chain branched polylactic acid-based copolymer prepared in example 6 of the present inventionThe polymer was analyzed by rheological test and the results showed that: the complex viscosity is 1.5 x 10 at an angular frequency of 0.1rad/s5Pa.S; the complex viscosity of the polylactic acid-based copolymer was higher than that of the polylactic acid/PBAT blend resin in example 1 throughout the shear frequency range at an angular frequency of 100rad/s of 3000pa.s, indicating that the polylactic acid-based copolymer prepared in example 6 of the present invention has a structure of long chain branches.
Example 7
7.1 after 1320g dimethyl terephthalate, 2000g sebacic acid, 3200g butanediol and 10g tetrabutyl titanate are added into a flask in sequence, the temperature is rapidly raised to 180 ℃ until no liquid is distilled off in the reaction, the temperature is raised to 240 ℃, and the polycondensation reaction is carried out by vacuumizing, wherein the pressure is 500Pa, and the number average molecular weight is 1.6 ten thousand, so as to obtain the poly (butylene sebacate-co-butylene terephthalate) copolymer.
7.2 repeatedly vacuumizing and filling nitrogen to cool a 3L round-bottom flask with a branch pipe, filling nitrogen, adding 9g of benzyl alcohol, 1440g of levorotatory lactide and 4g of stannous octoate, reacting at 130 ℃, heating to 180 ℃ after 20 hours of reaction, vacuumizing to remove unreacted monomers, and obtaining the monohydroxy polylactic acid with the number average molecular weight of 1.5 ten thousand, wherein the pressure is 100Pa.
Reacting 200g of monohydroxy polylactic acid in 7.2 with 1.09g of pyromellitic dianhydride at 180 ℃, stirring the reactants, adding 1.8g of styrene oxide after reacting for 1 hour, and continuously stirring for 1 hour to obtain dihydroxy polylactic acid; then 200g of poly (butylene sebacate-co-butylene terephthalate) in 7.1 and 15g of 4, 4-diisocyanato-3, 3-dimethylbiphenyl methane are added and stirred for 30min to obtain a long-chain branched polylactic acid-based copolymer, and the measured melt index of the copolymer is 1.6g/10min; hot pressing the sheet material on a flat vulcanizing machine at 200 ℃ and 10MPa to obtain a sheet material with the thickness of 1.0 mm.
According to the method of the technical scheme, the product prepared in the embodiment 7 of the invention is subjected to performance detection, and the detection result shows that the elongation at break of the long-chain branched polylactic acid-based copolymer obtained in the embodiment 7 of the invention is 510%.
Preparation of example 7 of the inventionThe prepared long-chain branched polylactic acid-based copolymer is subjected to rheological test analysis, and the result shows that: complex viscosity of 9.8 x 10 at an angular frequency of 0.1rad/s4Pa.S; the complex viscosity of the polylactic acid-based copolymer was higher than that of the polylactic acid/PBAT blend resin in example 1 throughout the shear frequency range at an angular frequency of 100rad/s of 2900pa.s, indicating that the polylactic acid-based copolymer prepared in example 7 of the present invention has a structure of long chain branches.
Example 8
8.1 adding 1180g succinic acid, 1100g butanediol and 5g tetrabutyl titanate into a flask in sequence, rapidly heating to 170 ℃ until no liquid is distilled off, heating to 230 ℃, vacuumizing, and carrying out polycondensation reaction under the pressure of 500Pa and 4 hours to obtain the poly (butylene succinate) with the number average molecular weight of 1.3 ten thousand.
8.2 reacting 150g of monohydroxy polylactic acid prepared in 7.2 of example 7 with 1.09g of pyromellitic dianhydride at 160 ℃, stirring the reaction product, adding 2.1g of allyl glycidyl ether after the reaction for 3h, and continuing stirring for 2h to obtain dihydroxy polylactic acid; then, 300g of 8.1 parts of polybutylene succinate and 10g of 4, 4-diisocyanato-3, 3-dimethylbiphenylmethane ester are added and stirred for 2 hours to obtain a long-chain branched polylactic acid-based copolymer, and the measured melt index of the copolymer is 2g/10min; hot pressing the sheet material on a flat vulcanizing machine at 190 ℃ and 10MPa to obtain a sheet material with the thickness of 1.0 mm.
The product prepared in the embodiment 8 of the present invention is subjected to performance detection according to the method described in the above technical scheme, and the detection result shows that the elongation at break of the long-chain branched polylactic acid-based copolymer obtained in the embodiment 8 of the present invention is 610%.
Rheological test analysis is carried out on the long-chain branched polylactic acid-based copolymer prepared in the embodiment 8 of the invention, and the result shows that: the complex viscosity at an angular frequency of 0.1rad/s is 8.5 x 104Pa.S; the complex viscosity of the polylactic acid-based copolymer was 2700Pa.S at an angular frequency of 100rad/s, which was higher than that of the polylactic acid/PBAT blend resin of example 1 throughout the entire shear frequency range, indicating that the polylactic acid-based copolymer prepared in example 8 of the present invention hasA structure having long chain branches.
Example 9
9.1 adding 1460g of adipic acid, 1100g of butanediol and 5g of tetrabutyl titanate into a flask in sequence, then rapidly heating to 170 ℃ until no liquid is distilled off, heating to 230 ℃, vacuumizing for polycondensation reaction, wherein the pressure is 500Pa, and after 5h, obtaining the polybutylene adipate with the number average molecular weight of 1.5 ten thousand.
9.2 reacting 150g of the monohydroxypolylactic acid prepared in 7.2 of example 7 with 1.09g of pyromellitic dianhydride at 170 ℃, stirring the reaction product for 1h, adding 2.4g of phenyl glycidyl ether, and continuing stirring for 1h to obtain dihydroxy polylactic acid; then 250g of 9.1 polybutylene adipate and 10g of isophorone diisocyanate are added and stirred for 1 hour to obtain a long-chain branched polylactic acid-based copolymer, and the measured melt index of the copolymer is 1.8g/10min; hot pressing the sheet material on a flat vulcanizing machine at 180 ℃ and 10MPa to obtain a sheet material with the thickness of 1.0 mm.
According to the method of the technical scheme, the product prepared in the invention in the embodiment 9 is detected, and the detection result shows that the elongation at break of the long-chain branched polylactic acid-based copolymer obtained in the embodiment 9 is 560%.
Rheological test analysis is carried out on the long-chain branched polylactic acid-based copolymer prepared in the embodiment 9 of the invention, and the result shows that: the complex viscosity at an angular frequency of 0.1rad/s is 3.5 x 105Pa.S; the complex viscosity of the polylactic acid-based copolymer was higher than that of the polylactic acid/PBAT blend resin in example 1 throughout the shear frequency range at an angular frequency of 100rad/s of 3600pa.s, indicating that the polylactic acid-based copolymer prepared in example 9 of the present invention has a structure of a long chain branch.
Example 10
10.1 Add 1460g adipic acid, 1400g hexanediol and 5g tetrabutyl titanate into the flask in turn, then raise the temperature to 170 ℃ rapidly until no liquid is distilled off, raise the temperature to 230 ℃ and vacuumize to carry out polycondensation reaction, after the pressure is 500Pa,4h, get poly adipic acid hexanediol ester, the number average molecular weight is 1.2 ten thousand.
10.2 repeated vacuum pumping and nitrogen filling are carried out to cool a 3L round-bottom flask with a branch pipe, nitrogen filling is carried out, 14g of benzyl alcohol, 1440g of levorotatory lactide and 6g of stannous octoate are added to carry out reaction at 130 ℃, after the reaction is carried out for 20h, the temperature is increased to 180 ℃, vacuum pumping is carried out to remove unreacted monomers, the pressure is 100Pa, and the monohydroxy polylactic acid with the number average molecular weight of 1.1 ten thousand is obtained.
10.3 reacting 150g of the monohydroxy polylactic acid in 10.2 with 1.09g of pyromellitic dianhydride at 170 ℃, stirring the reactants, adding 2.3g of 2-toluene glycidyl ether after reacting for 2 hours, and continuously stirring for 2 hours to obtain dihydroxy polylactic acid; then 200g of 10.1 polyhexamethylene glycol adipate and 12g of 4,4' -methylene bis (phenyl isocyanate) are added and stirred for 30min to obtain a long-chain branched polylactic acid-based copolymer, and the melt index of the copolymer is measured to be 3.5g/10min; hot pressing the mixture on a flat vulcanizing machine to obtain a sheet, wherein the hot pressing temperature is 190 ℃, and the pressure is 12MPa, so that a sheet with the thickness of 1.0mm is obtained.
According to the method of the technical scheme, the product prepared in the embodiment 10 of the present invention is detected, and the detection result shows that the breaking elongation of the long chain branched polylactic acid based copolymer prepared in the embodiment 10 of the present invention is 520%.
Rheological test analysis is carried out on the long-chain branched polylactic acid-based copolymer prepared in the embodiment 10 of the invention, and the result shows that: the complex viscosity at an angular frequency of 0.1rad/s is 1.7 x 105Pa.S; the complex viscosity of the polylactic acid-based copolymer was 2800pa.s at an angular frequency of 100rad/s, which was higher than that of the polylactic acid/PBAT blend resin in example 1 throughout the entire shear frequency range, indicating that the polylactic acid-based copolymer prepared in example 10 of the present invention had a structure of long chain branches.
Example 11
11.1 adding 1180g succinic acid, 1400g hexanediol and 5g tetrabutyl titanate into a flask in sequence, rapidly heating to 170 ℃ until no liquid is distilled off, heating to 230 ℃, vacuumizing, and carrying out polycondensation reaction under the pressure of 500Pa and 4h to obtain the poly (hexylene succinate) with the number average molecular weight of 1.1 ten thousand.
11.2 reacting 150g of the monohydroxypolylactic acid prepared in 10.2 of example 10 with 1.09g of pyromellitic dianhydride at 160 ℃, stirring the reactants, adding 2.4g of 4-methoxyphenyl ethylene oxide after 5 hours of reaction, and continuing stirring for 3 hours to obtain the dihydroxypolylactic acid; then 250g of 11.1 g of hexanediol polysuccinate and 15g of trimethyl-1, 6-diisocyanatohexane are added and stirred for 1 hour to obtain a long-chain branched polylactic acid-based copolymer, and the measured melt index of the copolymer is 3g/10min; hot pressing the sheet material on a flat vulcanizing machine at 180 ℃ and 10MPa to obtain a sheet material with the thickness of 1.0 mm.
When the product prepared in the embodiment 11 of the present invention is detected according to the method described in the above technical solution, the detection result indicates that the elongation at break of the long chain branched polylactic acid based copolymer prepared in the embodiment 11 of the present invention is 580%.
Rheological test analysis is carried out on the long-chain branched polylactic acid-based copolymer prepared in the embodiment 11 of the invention, and the result shows that: complex viscosity of 2.2 x 10 at an angular frequency of 0.1rad/s5Pa.S; the complex viscosity of the polylactic acid-based copolymer was higher than that of the polylactic acid/PBAT blend resin in example 1 throughout the shear frequency range at an angular frequency of 100rad/s of 3100pa.s, indicating that the polylactic acid-based copolymer prepared in example 11 of the present invention had a structure of long chain branches.
Example 12
12.1 after 2160g of sebacic acid, 800g of glycol and 6g of tetrabutyl titanate are sequentially added into a flask, the temperature is quickly raised to 160 ℃ until no liquid is distilled off, the temperature is raised to 230 ℃, and the polycondensation reaction is carried out by vacuumizing at the pressure of 500Pa for 5 hours, thus obtaining the polyethylene glycol sebacate with the number average molecular weight of 1.0 ten thousand.
12.2 reacting 120g of the monohydroxypolylactic acid prepared in 10.2 of example 10 with 1.09g of pyromellitic dianhydride at 180 ℃, stirring the reaction product for 1h, adding 2.5g of glycidyl methacrylate, and continuing stirring for 1h to obtain the dihydroxypolylactic acid; then 150g of polyethylene glycol sebacate in 12.1 and 15g of 4,4' -diisocyanate dicyclohexylmethane are added and stirred for 30min to obtain a long-chain branched polylactic acid-based copolymer, and the melt index of the copolymer is 3.7g/10min; hot pressing the mixture on a flat vulcanizing machine to obtain a sheet, wherein the hot pressing temperature is 200 ℃, and the pressure is 10MPa, so that a sheet with the thickness of 1.0mm is obtained.
According to the method of the above technical scheme, when the product prepared in the embodiment 12 of the present invention is detected, the detection result shows that the elongation at break of the long-chain branched polylactic acid-based copolymer prepared in the embodiment 12 of the present invention is 530%.
Rheological test analysis is carried out on the long-chain branched polylactic acid-based copolymer prepared in the embodiment 12 of the invention, and the result shows that: the complex viscosity at an angular frequency of 0.1rad/s is 1.6 x 105Pa.S; the complex viscosity of the polylactic acid-based copolymer was higher than that of the polylactic acid/PBAT blend resin in example 1 throughout the shear frequency range at an angular frequency of 100rad/s of 2900pa.s, indicating that the polylactic acid-based copolymer prepared in example 12 of the present invention has a structure of long chain branches.
From the above embodiments, the present invention provides a method for preparing a long-branched-chain polylactic acid-based copolymer, including reacting polylactic acid with pyromellitic dianhydride to obtain polylactic acid with both ends of pyromellitic dianhydride connected, then reacting the polylactic acid with a monoepoxy compound to obtain polylactic acid with two hydroxyl groups, and then chain extending the polylactic acid with polyester under the action of a chain extender to obtain a long-branched-chain polylactic acid-based copolymer with a main chain being a flexible chain segment and a side chain being polylactic acid. Compared with the existing polylactic acid-polyester copolymer, in the polylactic acid-based copolymer prepared by the method provided by the invention, polylactic acid is introduced into the copolymer in a side chain mode, and the polyester chain segment copolymer with a flexible main chain has good flexibility and high mechanical property; the polylactic acid-based copolymer prepared by the invention has controllable branched chain length and controllable number, and can effectively adjust the melt strength of the copolymer; the preparation method of the polylactic acid-based copolymer breaks through the traditional preparation method of the polylactic acid-based copolymer, the melt index of the prepared polylactic acid-based copolymer exceeds that of polylactic acid and polyester, and the polylactic acid-based copolymer can directly replace various current plastic products; the modified components used in the invention are all degradable substances, the preparation cost is low, and the biodegradability is good. The experimental results show that: the breaking elongation of the polylactic acid-based copolymer provided by the invention is up to 650 percent; the results of the rheological tests show that the complex viscosity of the polylactic acid-based copolymer is higher than that of the polylactic acid/PBAT blend resin in the whole shear frequency range.
While only the preferred embodiments of the present invention have been described, it should be understood that various modifications and adaptations thereof may occur to one skilled in the art without departing from the spirit of the present invention and should be considered as within the scope of the present invention.
Claims (9)
1. A long chain branched polylactic acid based copolymer comprising: formula I and/or formula II:
in the formula I, R is CH3-(CH2)q-，q＝0～21；
n＝150～600；
V is- (CH)2)i-，i＝2～10；
T is- (CH)2)t-，t＝1～8；
T' is a group remained after epoxy groups of the monoepoxy compound are removed;
s is the residual group of diisocyanate after removing isocyanate group;
m＝5～20；
X＝30～395；
in the formula II, R is CH3-(CH2)q-，q＝0～21，
n＝150～600；
V is- (CH)2)i-，i＝2～10；
T is- (CH)2)t-，t＝1-8；
T' is a group remained after epoxy groups of the monoepoxy compound are removed;
s is the residual group of diisocyanate after removing isocyanate group;
m＝5～20；
Z＝0～176；
X＝8～395。
2. a method for preparing a long chain branched polylactic acid based copolymer, comprising:
carrying out a first reaction on monohydroxy polylactic acid and pyromellitic dianhydride to obtain dicarboxyl polylactic acid;
carrying out a second reaction on the mono-epoxy compound and the bi-carboxyl polylactic acid to obtain bi-hydroxyl polylactic acid;
carrying out chain extension reaction on polyester and the dihydroxy polylactic acid under the action of a chain extender to obtain a long-chain branched polylactic acid-based copolymer;
the number average molecular weight of the monohydroxy polylactic acid is 1-5 ten thousand, and the melting point is 150-180 ℃.
3. The method of claim 2, wherein the temperature of the first reaction is from 150 ℃ to 220 ℃;
the time of the first reaction is 20 min-10 h.
4. The method of claim 2, wherein the temperature of the second reaction is 150 ℃ to 200 ℃;
the time of the second reaction is 20 min-5 h.
5. The method according to claim 2, characterized in that the temperature of the chain extension reaction is 160 ℃ to 220 ℃;
the time of the chain extension reaction is 8-60 min.
6. The method according to claim 2, wherein the mass ratio of the monohydroxypolylactic acid to pyromellitic dianhydride is (2 to 4): 1;
the mass ratio of the monoepoxy compound to the dicarboxy polylactic acid is (2-4): 1;
the mass ratio of the polyester to the dihydroxy polylactic acid is (1-9): (9-1);
the mass of the chain extender is 1-10% of the total mass of the polyester and the dihydroxy polylactic acid.
7. The method of claim 2, wherein the monohydroxy polylactic acid is selected from one or more of levorotatory polylactic acid and dextrorotatory polylactic acid.
8. The method of claim 2, wherein the monoepoxy compound is selected from one or more of propylene oxide, styrene oxide, allyl glycidyl ether, phenyl glycidyl ether, methyl propylene oxide, cis-2, 3-butylene oxide, 2-toluene glycidyl ether, (2-methoxyphenoxy) methyl ethylene oxide, n-butyl glycidyl ether, 1, 2-epoxydodecane, 1, 2-epoxyoctadecane, 4-methoxyphenylethylene oxide, epoxypropyl methyl ether, and glycidyl methacrylate.
9. The method according to claim 2, wherein the chain extender is selected from one or more of anhydride substances, heterocyclic substances, isocyanate substances, diacid chloride substances, trimethyl trimellitate and triphenyl phosphite.
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