聚l-乳酸的固相反应与乳酸—亮氨酸二聚体的制备.docx

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玩 a v ari ety o f n atural P o lym er an d oyn thotic 尹01卿 e瓦P olylactie aeid (P L A ) 15
th e m o st w id e ly stu d ie d s” th e tie d e 脚 d ab le p o lym er. N o t o n ly b e eau se 」o f the
d e g r a d a tio n P ro d u c ts o f P L A a re 也 e n o n 一to x ie W a te r a n d e a tb o n d io x id e P ro d u c ts , b u t P olylactie aeid h av e b etter P er肠二 an oe an d p ro cessin g P roP ecau se o f its SP e c ia l P ro P ertie s,th ere are a lo t o f u sin g 或n 橄 e m e d ical an d p a ck a g in g in d u stri e s n ow .A lthou gh the P L A are m ore w id ely u sed。伍e P LA itself h as m an y Shorteom in gs.
F or ex am p le P L A h as a h igh d eg ee o f cry stallin ity,50 伍e b rit妞en ess 15 to o larg e;th e
h igh m olecu lar w eigh t P olylaetic aeid are so exP en siv e; lac?k s o f b iologieal activ ity g r o u P s ,t hu s re d u c in g b io lo g ie a l c o m P a t汤 ility a n d 50 o n . In o r d e r to f u r th e r e x P a n d th e u sin g seoP e o f P olylaetie aeid an d to imP rov e P erform an ce o f P o ly lactic a e id ,m o d if ic a tio n o f th e P L A 15 a h o t re se a rc h in s c ,ie n tists in re c e n t y e a rs . T h is issu e
first u se m eth od of m elt P ol娜 erization to o b tain e p ol贝actie acid .A n d w e u se solid
P h a se P o ly ln e ri z a tio n a n d 丫一ra d ia tio n c r o sslin k in g m e th o d s to im P ro v e t h e m o le c u la r
w eigh t o f P olylaetie acid at sam e tim e redu ce the ,Cry stallin ity o f P o lylaetie aeid .W 亡 u se a m in o a c id s th a t c o n ta in e b io lo g ic a lly a e tiv e g r o u P s w it h la 以ic a e id to eoP ol卿 erize in order to m odify P L A .
① U sing stannou s octoate,stann ou s o cto ate and p 一tolu en e su lph on ie acid as
eataly st to m ak e th e P o ly lactie aeid ,resP ectiv ely. U sin g P olari zed ligh t m icro seoP y
f o u n d t ha t th e m o re o b v io u s b a ll e r y sta l .T h e re su lts o f D S C ,T G th e r m a l a n a ly sis
sh ow that