PLLA-PEG-PLLA三嵌段共聚物的合成及性能

Synthesis and Properties of PLLA-PEG-PLLA Triblock Copolymers

以萘钾和聚乙二醇形成大分子引发剂,在超声波震荡下引发L-丙交酯开环共聚,合成出不同EO/LA物质的量比的PLLA-PEG-PLLA三嵌段共聚物。利用FT-IR和1HNMR表征了三嵌段共聚物的结构。通过接触角和吸水率测试表明共聚物的亲水性是随着EO含量的增大而增强。采用DSC和POM研究共聚物的热性能和结晶形貌表明,共聚物各段熔点比各自均聚物低且有一个Tg,由于共聚物中EO/LA物质的量比的不同,表现出某段的单独结晶或两段都不结晶。因此,可通过改变嵌段含量,制备不同性能的材料,扩大聚乳酸的应用范围。

The ring-opening polymerization of L-lactide was initiated by macromolecular initiator which was made from potassium/naphthalene and poly（ethylene glycol） at the concussion of ultrasonic wave.PLLA-PEG-PLLA triblock copolymers with different EO/LA molar ratios were synthesized.The structures of these copolymers were characterized by FT-IR and 1H NMR.Contact angle and water absorption behaviors were tested.It is found that the hydrophilic property is enhanced with increasing the content of EO.Thermal properties and morphology development of triblock copolymers were studied by means of DSC and POM,the results show that melting peak of each block was lower than its homopolymer and only one Tg in the copolymer.Depending on the composition,only one block crystallized or two blocks didn＇t crystallize.Therefore,a series of copolymers with different properties could be synthesized by changing the content of the segment and they could be used in various applications.