WO2011060650A1

WO2011060650A1 - Biodegradable aromatic-aliphatic copolyester and preparation method thereof

Info

Publication number: WO2011060650A1
Application number: PCT/CN2010/075536
Authority: WO
Inventors: 顾群; 黎俊
Original assignee: 中国科学院宁波材料技术与工程研究所
Priority date: 2009-11-23
Filing date: 2010-07-29
Publication date: 2011-05-26
Also published as: CN101717494A; CN101717494B

Abstract

A biodegradable aromatic-aliphatic copolyester, which consists of aromatic polyester structural unit, polydiol structural unit and polyhydroxyacid polyester structural unit, is disclosed, and it is obtained by the melt polycondensation-solid phase polycondensation of low melting point aromatic polyester, polydiol and polylactic acid.

Description

Biodegradable aromatic-aliphatic copolyester and preparation method thereof

The present invention relates to a copolyester of biodegradable polylactic acid or polyglycolic acid, polyglycol and aromatic polyester, and to a process for preparing the copolyester. Background technique

Aromatic polyesters such as polyethylene terephthalate (PET), polytrimethylene terephthalate (PTT), polybutylene terephthalate (ΡΒΤ), due to its excellent mechanical properties, It is widely used in heat resistance and chemical resistance, and is currently used mainly in the fields of fibers, packaging and coatings. However, aromatic polyesters have a long degradation cycle, and their extensive use has caused great environmental pollution, making an unfriendly environment unfriendly material.

In order to improve the degradability of aromatic polyesters, researchers at home and abroad have carried out a lot of work, mainly focusing on two aspects of blending and copolymerization modification. In terms of blending, PET is mainly blended with natural polymers or synthetic polymer materials such as starch, PLA, PEG and PCL. The results of blending show that the degradation of easily degradable components can induce partial biodegradation of non-degradable materials. C* Bastoli has mentioned in Chinese patent application CN148961 that blending an aromatic-aliphatic polyester, an aliphatic polyester and a polylactic acid polymer can obtain a blend material having good biodegradability.

In terms of copolymerization modification, the degradation properties of the aromatic polyester are improved mainly by introducing structural units or segments of the aliphatic polyester onto the main chain of the aromatic polyester. Significant results have been achieved in this area, such as the PBAT copolyesters produced by BASF and Dupont under the trade names Ecoflex and Biomax, which are made from butanediol, adipic acid and terephthalic acid. The polycondensation reaction is synthesized and is a typical fully biodegradable aromatic-aliphatic copolyester material. In theoretical research, a wide range of copolymers have been prepared by transesterification, such as PET-PBS (Polym. Degrad. Stabi l. 2005; 88: 294-99), PET -PHB (Imu et al., Japanese Patent, 08 217 865 A2), PET-PCL (Tokiwa et al. Polymer degradation stability (Polym. Degrad. Stabi l.), 1994; 45: 205), PET-PEA (He idary Environmental Polymer Degradation (J. Environ. Polym. Degrad.), 1994; 2: 19), PET-PGA (Niekraszewicz and other Polish patents Pol i sh patent, 171 062 Bl; Polymer Preparation (Polym. Prepr.) , 1989; 30: 197). However, the reaction temperature of this series of reactions is high, the degradation of aliphatic polyester is severe, and the transesterification efficiency is low. Kuo et al. (JP2001 187819) reported a polytrimethylene terephthalate and polyparaphenylene Copolyester of ethylene glycol dicarboxylate with bishydroxyethyl terephthalate (BHET) and terephthalic acid (PTA) and 1,3-propanediol (?00) in the presence of tetraethyl titanate The esterification is carried out, and polymerization is carried out in the presence of cerium acetate and cobalt acetate to obtain a copolyester having a certain viscosity. This copolyester is suitable for the production of fibers, but the biodegradability is extremely slow.

Among them, polyalcoholic acid (PLA), polyglycolic acid (PGA) and other hydroxyalkyd polymers are a very promising biodegradable material. They not only have good biodegradability, but also have biomass properties. Environmentally friendly materials. The main chain of these substances consists of ester bonds, which are easily degraded into oligomers or monomers by a large number of microorganisms or enzymes in animals and plants in nature, and then converted into carbon dioxide and water by microorganisms. It is a completely natural circulation type. Biodegradable materials, therefore, copolymerization of such polymers with aromatic polyesters can develop a biodegradable copolyester material.

Acar et al. (Polym-Plast Tech Eng 2006; 45: 351-59) reported the use of polylactic acid and recycled PET polyester as raw materials, dibutyltin oxide as catalyst in o-nitrophenol solution. The copolymerization was carried out to obtain a multi-block copolyester of polyethylene terephthalate-poly-L-lactic acid, but they were not reported on material-related properties and structures.

Olewnik et al. (European Polymer Journal 2007; 43: 1009-19) reported a multi-block copolyester of polyethylene terephthalate-poly L-lactic acid. However, the transesterification catalyst used in the system, stannous chloride and p-toluenesulfonic acid, easily catalyze the formation of by-product lactide at the higher temperature by the lactic acid multimer, and consume a large amount of polylactic acid; The alcohol ester multimer has a high melting point (210~225 °C), high transesterification temperature, and polylactic acid is easily degraded at a high transesterification temperature, so that the polycondensation reaction of the system cannot be completely carried out, so the obtained product The molecular weight is only a few thousand and cannot be used as a material.

In summary, it is necessary to develop a degradable copolyester and a suitable preparation process. Summary of the invention

The first technical problem to be solved by the present invention is to provide an aromatic-aliphatic copolyester having a high molecular weight, easy synthesis, and biodegradability in view of the above state of the art.

A second technical problem solved by the present invention is to provide a process for preparing an aromatic-aliphatic copolyester which is simple and inexpensive.

The technical idea adopted by the present invention to solve the above first technical problem is as follows: A biodegradable copolyester consisting of one or more aromatic polyester structural units, a polyglycol structural unit and polylactic acid, It is composed of one or more structural units in a polyhydroxy acid polyester such as polyglycolic acid. The technical solution adopted by the present invention to solve the above second technical problem is: first melt polycondensation, followed by solid phase polycondensation. details as follows:

The transesterification product of the aromatic polyester and the polyglycol and the hydroxy acid polyester prepolymer are subjected to melt polycondensation under the action of a catalyst under the action of a catalyst of 160 to 300 Torr under reduced pressure, and the reaction is carried out. 5-8h to obtain a certain molecular weight of the copolymer; then add a certain amount of catalyst, melt and mix evenly and then extrude granulation to obtain the initial section; finally sliced in 140~17 (TC, high vacuum conditions (0. 03KPa) Solid phase polycondensation is carried out, and a high molecular weight copolyester is obtained after 6 to 32 hours of reaction.

Compared with the prior art, the invention has the advantages that: the copolyester of the invention is easy to synthesize, has high molecular weight, can be a biodegradable material, and combines the heat resistance of the aromatic polyester with the aliphatic polyester. The biodegradability, the copolymer can be widely applied to fiber materials and plastic products, and the preparation method is simple in process and low in cost. BEST MODE FOR CARRYING OUT THE INVENTION

The invention is further described in detail below with reference to the embodiments.

Example 1. Preparation of polyethylene terephthalate-polyethylene glycol-polylactic acid copolyester

1) Preparation of polyethylene terephthalate prepolymer

5〜0. 0. 3~0. The mixture of the mixture is added in a one-liter reaction vessel at 230~250 ° C, 0. 3~0. The prepolymer of the intrinsic viscosity is 0.32. The polycondensation reaction is carried out at a temperature of 270 to 280 ° C, 0. 07 KPa, and a prepolymer having an intrinsic viscosity of 0.32 is finally obtained.

2) Preparation of polyethylene terephthalate-polyethylene glycol copolymer

300 g of polyethylene terephthalate prepolymer, 100 g of polyethylene glycol (^SOOOg/mol

0. 5 bismuth trioxide and 0. 05g of triphenyl phosphate were blended at 250 ° C under high vacuum ( < 0. 07KPa) for 30 minutes, and then rapidly heated to about 275 进行 for transesterification and polycondensation reaction. 3. After 5 h, a polyethylene terephthalate-polyethylene glycol copolymer having an intrinsic viscosity of 0.54 was obtained.

3) Preparation of polylactic acid prepolymer

The lyophilized solution of the aqueous solution of L-lactic acid (88%) (200%) and the mixture of 3 g of butane diol was subjected to atmospheric distillation in a liter polymerization vessel. After dehydration was more than 90%, 0.02 g of stannous octoate catalyst was added, and the mixture was stirred and heated to 180 ° C. The pressure was gradually reduced to 70 Pa, and preliminary polycondensation was carried out for 2 hours to obtain a white powdery terminal hydroxylactic acid prepolymer. The prepolymer had a weight average molecular weight of 5 kg/mol as determined by gel permeation chromatography (GPC), and a melting point of 126 ° C as measured by differential scanning calorimetry (DSC). 4) Preparation of polyethylene terephthalate-polyethylene glycol-polylactic acid

300克稳定稳定三三。 300 g polyethylene terephthalate-polyethylene glycol copolymer, 45 g polylactic acid prepolymer, 0. lg tetrabutyl titanate catalyst, 0. 3g titanium dioxide, 0. 05g stabilizer phosphoric acid three The phenyl ester was added to a 1 L polymerization vessel, and the polycondensation reaction was carried out under reduced pressure at 225-235 Torr, and the reaction was carried out under high vacuum (<0.07 KPa) for 5. 2 h to obtain polyethylene terephthalate-polyethylene. The alcohol-polylactic acid copolymer had a weight average molecular weight of 71 kg/mol and a melting point of 193 °C by GPC. To the melt was added 0.33 g of catalyst stannous chloride, and the mixture was uniformly mixed and extruded into pellets.

5) Solid phase polycondensation

50 g of the above slice was subjected to solid phase polycondensation at 170 ° C under high vacuum (< 0.03 KPa), and polycondensation was carried out for 30 hours to obtain a high molecular weight polyethylene terephthalate-polyethylene glycol-polylactic acid copolymer. The weight average molecular weight of GPC was 88 Kg/mol. Example 2. Preparation of polyethylene terephthalate-polyethylene glycol-polylactic acid copolyester

1) Preparation of polyethylene terephthalate prepolymer

2) Preparation of polyethylene terephthalate-polyethylene glycol copolymer

300 g of polyethylene terephthalate prepolymer, 100 g of polyethylene glycol (4000 g/mol),

0. 5 bismuth trioxide and 0. 05g of triphenyl phosphate at 250 ° C, under high vacuum (< 0. 07KPa) for 30 minutes, and then rapidly heated to 275 °C for transesterification and polycondensation reaction, After the reaction for 2.5 h, a polyethylene terephthalate-polyethylene glycol copolymer having an intrinsic viscosity of 0.48 was obtained.

3) Preparation of polylactic acid prepolymer

The lyophilized solution of the aqueous solution of L-lactic acid (88%) (200%) and the mixture of 3 g of butane diol was subjected to atmospheric distillation in a liter polymerization vessel. After dehydration was more than 90%, 0.02 g of stannous octoate catalyst was added, and the mixture was stirred and heated to 180 ° C. The pressure was gradually reduced to 70 Pa, and the initial polycondensation was carried out for 2 hours to obtain a white powdery terminal hydroxylactic acid prepolymer. The prepolymer had a weight average molecular weight of 5 kg/mol as determined by gel permeation chromatography (GPC) and a melting point of 126 ° C by differential scanning calorimetry (DSC).

4) Preparation of polyethylene terephthalate - polyethylene glycol - polylactic acid

300 g of polyethylene terephthalate-polyethylene glycol copolymer, 100 g of polylactic acid prepolymer, 0. 07克帕的反应。 The lg tetrabutyl titanate catalyst, 0. 4g titanium dioxide, 0. 07g stabilizer triphenyl phosphate was added to a 1L polymerizer, gradually reduced pressure at 225-235 to carry out polycondensation, vacuuming to < 0. 07KPa, reaction 5h, a polyethylene terephthalate-polyethylene glycol-polylactic acid copolymer was obtained, and the weight average molecular weight was 55 Kg/mol and the melting point was 182 °C by GPC. To the melt was added 0.131 g of stannous chloride chloride, and the mixture was uniformly mixed and then extruded into pellets.

5) Solid phase polycondensation

50 g of the above slice was subjected to solid phase polycondensation at 155 ° C under high vacuum (< 0. 03 KPa), and polycondensation was carried out for 30 h to obtain a high molecular weight polyethylene terephthalate-polyethylene glycol-polylactic acid copolymer. The weight average molecular weight of GPC was determined to be 85 kg/mol. Example 3. Preparation of polyethylene terephthalate-polyethylene glycol-polylactic acid copolyester

1) Preparation of polyethylene terephthalate prepolymer

2) Preparation of polyethylene terephthalate-polyethylene glycol copolymer

300g polyethylene terephthalate prepolymer, 60g polyethylene glycol (= 4000g / mol), 0. 5g antimony trioxide and 0. 05g triphenyl phosphate at 250 ° C, high vacuum After the next ( < 0. 07KPa) blending for 30 minutes, and then rapidly heating to 275 进行 for transesterification and polycondensation reaction, after 4 h of reaction, obtaining polyethylene terephthalate-polyethylene having an intrinsic viscosity of 0.57. Glycol copolymer.

3) Preparation of polylactic acid prepolymer

The lyophilized solution of the aqueous solution of L-lactic acid (88%) (200%) and the mixture of 3 g of butane diol was subjected to atmospheric distillation in a liter polymerization vessel. After dehydration was more than 90%, 0.02 g of stannous octoate catalyst was added, and the mixture was stirred and heated to 180 ° C. The pressure was gradually reduced to 70 Pa, and preliminary polycondensation was carried out for 2 hours to obtain a white powdery terminal hydroxylactic acid prepolymer. The prepolymer had a weight average molecular weight of 5 kg/mol as determined by gel permeation chromatography (GPC) and a melting point of 126 ° C by differential scanning calorimetry (DSC).

300克稳定稳定三三。 300 g polyethylene terephthalate-polyethylene glycol copolymer, 100 g polylactic acid prepolymer, 0. lg tetrabutyl titanate catalyst, 0.4 g titanium dioxide, 0. 07g stabilizer phosphoric acid three 5小时,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,, A polyethylene terephthalate-polyethylene glycol-polylactic acid copolymer was obtained, and the weight average molecular weight was 58 Kg/mol and the melting point was 182 °C by GPC. To the melt was added 0.131 g of stannous chloride chloride, and the mixture was uniformly mixed and then extruded into pellets.

5) Solid phase polycondensation

50 g of the above slice was subjected to solid phase polycondensation at 155 ° C under high vacuum (< 0. 03 KPa), and a high molecular weight polyethylene terephthalate-polyethylene glycol-polylactic acid copolymer was obtained after polycondensation for 36 hours. The weight average molecular weight of GPC was 92 Kg/mol. Example 4. Preparation of polyethylene terephthalate-polyethylene glycol-polylactic acid random copolyester 1) Preparation of polyethylene terephthalate prepolymer

5〜0. 0. 3~0. The mixture of the mixture is added in a one-liter reaction vessel at 230~250 ° C, 0. 3~0. The prepolymer BHET having an intrinsic viscosity of 0.32 is obtained. The polycondensation reaction is carried out at a temperature of 270 to 280 ° C.

2) Preparation of polyethylene terephthalate-polyethylene glycol copolymer

300g polyethylene terephthalate prepolymer, 120g polyethylene glycol (M _w = 6 000g / mol), 0. 5g of antimony trioxide and 0. 05g of triphenyl phosphate at 25CTC, high聚聚乙乙乙二二。 After the vacuum (< 0. 07 Pa) was blended for 30 minutes, and then rapidly heated to 275 °C for transesterification and polycondensation reaction, after the reaction for 4.5 h to obtain an intrinsic viscosity of 0.52 polyethylene terephthalate Alcohol ester-polyethylene glycol copolymer.

3) Preparation of polylactic acid prepolymer

300克稳定稳定三三。 300 g polyethylene terephthalate-polyethylene glycol copolymer, 120 g polylactic acid prepolymer, 0. 2g tetrabutyl titanate catalyst, 0.4 g titanium dioxide, 0. 07g stabilizer phosphoric acid three The phenyl ester was added to a 1 L polymerization vessel, and the polycondensation reaction was carried out under reduced pressure at 225-235. The vacuum was reduced to <0.07 PaPa, and the reaction was carried out for 5. 5 hours to obtain polyethylene terephthalate-polyethylene glycol-polylactic acid. The copolymer had a weight average molecular weight of 68 kg/mol and a melting point of 182 ° C by GPC. To the melt was added 0.42 g of catalyst stannous chloride, and the mixture was uniformly extruded. Granulation sections.

5) Solid phase polycondensation

50 g of the above slice was subjected to solid phase polycondensation at 155 ° C under high vacuum (< 0. 03 KPa), and polycondensate was obtained for 32 hours to obtain a high molecular weight polyethylene terephthalate-polyethylene glycol-polylactic acid copolymer. The weight average molecular weight of GPC was determined to be 89 kg/mol. Example 5. Preparation of polytrimethylene terephthalate-polyethylene glycol-polylactic acid random copolyester

1) Preparation of polytrimethylene terephthalate prepolymer

4MPa下下下下下下下下下下下下下下下下下下下下下下下下下下下下下下下下下下下下下下下下下下下下下下下下下下下下下下下下下下下下下下下下下下下下下下下下下下下下下下下下下下下下下下下下下下下下下下下下下下下下下下下下下下The prepolymer BHTT having an intrinsic viscosity of 0.45 is obtained by the polycondensation reaction at a temperature of 250 to 260 ° C, 0. 07 KPa. .

2) Preparation of polytrimethylene terephthalate-polyethylene glycol copolymer

300g polytrimethylene terephthalate prepolymer, 120g polyethylene glycol (M _w = 6 000g / mol), 0. 5g of antimony trioxide and 0. 05g of triphenyl phosphate at 230 ° C, high The poly(trimethylene terephthalate-polyethylene glycol) having an intrinsic viscosity of 0.53 was obtained after blending for 30 minutes under vacuum (<0.07 KPa), and then rapidly heating to about 255 for transesterification and polycondensation. Block copolymer.

3) Preparation of polylactic acid prepolymer

4) Preparation of polytrimethylene terephthalate - polyethylene glycol - polylactic acid

300 g of polytrimethylene terephthalate-polyethylene glycol copolymer, 120 g of polylactic acid prepolymer,

0. 2g tetrabutyl titanate catalyst, 0.4g titanium dioxide, 0. 07g stabilizer triphenyl phosphate was added to a 1L polymerizer, and gradually reduced pressure at 225-235 to carry out polycondensation reaction under high vacuum (< 0. 07KPa The reaction was carried out for 5 hours to obtain a polytrimethylene terephthalate-polyethylene glycol-polylactic acid copolymer having a weight average molecular weight of 68 kg/mol and a melting point of 176 ° C as determined by GPC. To the melt, 0.42 g of stannous chloride chloride was added, and after mixing, the granulated sections were extruded.

5) Solid phase polycondensation 50g of the above slice was subjected to solid phase polycondensation at 150 ° C under high vacuum (< 0. 03 KPa), and polycondensation was carried out for 33 h to obtain a high molecular weight polytrimethylene terephthalate-polyethylene glycol-polylactic acid copolymer, as determined by GPC. The weight average molecular weight was 92 kg/mol.

Claims

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A biodegradable aromatic-aliphatic copolyester characterized in that the copolyester is composed of an aromatic polyester structural unit, a polyglycol structural unit and a polyhydroxy acid polyester structural unit, and is composed of a low melting point. Aromatic polyester, polyglycol and polylactic acid are melted polycondensation-solid phase, and the structural formula is as follows:

The biodegradable copolyester according to claim 1, wherein the low-melting aromatic polyester is obtained by copolymerizing a dibasic acid with a glycol.

The copolyester according to claim 2, wherein the dibasic acid is terephthalic acid, isophthalic acid, 1,4-naphthalene dicarboxylic acid, 2,6-naphthalene dicarboxylic acid, and the structural formula is One or more of the compounds of H00C(CH ₂ )nC00H(23⁄4Sn3⁄4S6).

The copolyester according to claim 2, wherein the diol is one or more of compounds of the formula H0(CH ₂ ) „0H(2 n 6).

The biodegradable copolyester according to claim 1, wherein the polyglycol is a copolymer of a diol having a structural formula of H0(R0) _n H and a molecular weight of 1000 to 6000 g/mol. .

The biodegradable copolyester according to claim 5, wherein the diol is one or more of compounds of H0(CH ₂ ) „0H(2 n 6).

The biodegradable copolyester according to claim 1, wherein the hydroxy acid is a compound containing a hydroxyl group and a carboxyl group, such as L-lactic acid, D-lactic acid, D, L-lactic acid or glycolic acid. One or several.

8. A method for preparing a biodegradable copolyester, characterized in that an esterification product of an aromatic polyester and a polyglycol are subjected to transesterification to obtain a low melting point copolyester; Polyester and polyhydroxy acid prepolymer are melt-polycondensed under a reduced ratio (< 0.07 KPa) at a certain ratio, and the temperature is controlled at 160-300 ° C, and the reaction is 0.5-8 h to obtain a copolymer of a certain molecular weight; Add a certain amount The catalyst is melted and mixed uniformly and then extruded and granulated to obtain an initial section; finally, the section is subjected to solid phase polycondensation under conditions of 140 to 170 ° C under high vacuum (< 0.03 KPa), and a high molecular weight is obtained after 6 to 32 hours of reaction. Copolyester.

The preparation method according to claim 8, wherein the catalyst is a catalyst which is one or more compounds containing a metal element of zinc, lanthanum, manganese, cobalt or tin.

10. The preparation method according to claim 9, wherein the catalyst is tetrabutyl titanate, tetraisobutyl titanate, titanium dioxide, zinc acetate, zinc oxide, barium acetate, barium trioxide, acetic acid. One or more of cobalt, stannous chloride and stannous octoate.