Method for preparing high molecular weight biodegradable polyester by combined chain extension

A biodegradable, high-molecular-weight technology, applied in the field of preparation of aliphatic polyesters, can solve the problems of time-consuming, complicated operation, high degree of reaction, etc., and achieve the effects of high molecular weight, simple preparation method, and reduced consumption

Inactive Publication Date: 2009-05-20
BEIJING UNIV OF CHEM TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

In the patent 200710064535.5 we have applied for, binary oxazoline is also used to extend the chain to prepare high molecular weight aliphatic polyester, but the prepolymers used in these two methods often need carboxyl groups at both ends to achieve Ideal chain extension effect, so the preparation process of the prepolymer requires a strict ratio of raw materials, a high degree of reaction, complicated operation, and time-consuming

Method used

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  • Method for preparing high molecular weight biodegradable polyester by combined chain extension
  • Method for preparing high molecular weight biodegradable polyester by combined chain extension
  • Method for preparing high molecular weight biodegradable polyester by combined chain extension

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0042] Embodiment 1: the preparation of polybutylene adipate (PBA) prepolymer: with 50 parts of adipic acid, 31 parts of butanediol in parts by weight, 0.24 part of dibutyl tin oxide, 0.08 part of phosphorous acid, Under the protection of nitrogen, gradually increase the temperature from 160°C to 200°C for polycondensation reaction. After collecting 70-80% of the generated water, use a decompression device. First, use a water pump to gradually depressurize the reaction for 3-4 hours, and then use an oil pump to depressurize. Reduce the pressure to 1 mmHg, and continue to react for 3 to 4 hours at a temperature range of 190 to 210 °C until the acid value remains basically unchanged. The number average molecular weight is 4300, the intrinsic viscosity is 0.35 dL / g, and the acid value is 36.2 mgKOH / g. A PBA prepolymer with a hydroxyl value of 8.4 mgKOH / g.

Embodiment 2

[0043] Embodiment 2: 100 parts by weight of PBA oligomers prepared in Example 1 (the number average molecular weight is 4300), 2.6 parts of N, N'-adipyl biscaprolactam, 6.9 parts of 1,4-phenyl-biscaprolactam (2-oxazoline), react under reduced pressure at 180° C. for 3 hours under the protection of nitrogen, and the number average molecular weight of the obtained polymer is 11860.

Embodiment 3

[0044] Example 3: Referring to Example 2, the chain extension temperature was changed to 200°C, and the other conditions were exactly the same. The number average molecular weight of the obtained polymer was 25740, the Mw was 159398, and the intrinsic viscosity was 0.87dL / g.

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Abstract

The invention relates to a method for preparing biodegradable polyester. Firstly, melt polycondensation is conducted through diol and dicarboxylic acid and a low molecular weight polyester prepolymer with number average molecular weight between 2, 000 and 20, 000 or intrinsic viscosity below 0.64dL/g is prepared; binary oxadiazoline and diacyl bis-caprolactamate are combined to extend chain, and chain extension is carried out at a certain temperature; and the biodegradable polyester is obtained. The number average molecular weight of polybutylene adipate (PBA) can reach up to 39, 000 and the intrinsic viscosity to 1.13dL/g. For poly (butylene succinate) (PBS) with relatively high melting point, the intrinsic viscosity after chain extension is up to 0.99dL/g.

Description

technical field [0001] The invention relates to a preparation method of aliphatic polyester, in particular to a high molecular weight biodegradable polyester with a number average molecular weight of 20,000 to 39,000 and an intrinsic viscosity of 0.69 to 1.13 dL / g by a two-step method of polycondensation and chain extension. ester method. Background technique [0002] The good degradation performance of biodegradable polyester makes it the focus of people's attention. At the same time, it also has good mechanical properties and can be widely used in many fields such as agriculture, fishery, medical treatment, and packaging. [0003] In recent years, various methods have been used to obtain high molecular weight aliphatic polyesters. Aliphatic polyester is prepared by the usual polycondensation method. Due to the high polymerization temperature and side reactions such as thermal decomposition and thermal oxidation, it is difficult to obtain high molecular weight aliphatic po...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C08G63/16C08G63/78C08G63/85C08K5/353
Inventor 赵京波史艳红杨万泰
Owner BEIJING UNIV OF CHEM TECH
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