采用羧基封端乳酸预聚物与聚乙二醇熔融缩聚合成了聚乳酸-聚乙二醇共聚物,并用GPC、FTIR、1H-NMR等方法表征了预聚物与共聚物,结果表明,预聚物的羧基封端率高于95%,预聚物的相对分子质量可由投料比(物质的量比)控制.热分析结果表明,共聚物中聚乳酸链段呈无规分布,而聚乙二醇链段能够形成结晶微区.力学性能测试结果表明,共聚物的断裂伸长率达371%,有望在聚乳酸韧性改性方面得到应用.
Poly(L-lactic acid)-poly(ethylene glycol)(PLA-PEG)copolymers are synthesized by the melt copolycondensation of poly(ethylene glycol)(PEG) and carboxyl terminated lactic acid prepolymer. The chemical compositions of the prepolymers and copolymers are characterized by 1 H-NMR and FT-IR, the molecular weight and distribution are measured by GPC. The results show that the yield of termination of prepolymers is above 950%, and the molecular weight of prepolymers can be controlled by the feed ratio of L-lactic acid to succinic acid. DSC thermogram demonstrates that PLLA segments in copolymers distributes randomly, while PEG segments can form crystalline micro-domains. According to the tensile test,the breaking elongation rate of copolymer reaches 371% ,which indicates that the copolymer can be used to improve the impact strength of PLA.
参考文献
| [1] | Schreck KM;Hillmyer MA .Block copolymers and melt blends of polylactide with Nodax microbial polyesters: preparation and mechanical properties[J].Journal of Biotechnology,2007(3):287-295. |
| [2] | Vidovic E;Klee D;Hocker H .Synthesis and characterization of poly(vinyl alcohol)-graft-[poly(D,L-lactide)/poly(D,L-lactide-co-glycolide)] hydrogels[J].Journal of Polymer Science, Part A. Polymer Chemistry,2007(19):4536-4544. |
| [3] | 赵耀明,周玲,汪朝阳.聚（己内酯-乳酸）的直接熔融法合成及表征[J].华南理工大学学报（自然科学版）,2006(07):7-11. |
| [4] | 王方,汪朝阳,赵耀明.聚乙二醇改性聚乳酸类材料研究进展[J].材料导报,2004(02):62-64. |
| [5] | 樊国栋,杨海燕.聚乙二醇对聚乳酸的共聚改性研究[J].塑料,2009(01):51-53. |
| [6] | Espantero J L;Rashkov I;Li S M et al.NMR analysis of low molecular weight poly (lactic dacid) s[J].Macromolecules,1996,29:3535. |
| [7] | 戈进杰.生物降解高分子材料及其应用[M].北京:化学工业出版社,2002:285. |
- 下载量()
- 访问量()
- 您的评分：
-
10%
-
20%
-
30%
-
40%
-
50%