臺灣博碩士論文加值系統

以左旋乳酸(L-lactic acid)與琥珀酸酐(succinic anh- ydride)合成一
diacid中間體，此diacid分別與EG鏈長200 的 PEG單體,聚縮合成橡膠態
共聚酯與醚基.酯基均勻分散在分子鏈中的聚酯醚,反應產物以GPC,IR,
H-NMR,DSC,接觸角儀等,分析其結構、熱性質以及潤溼性,並以一級動力學
模式求得水解速率常數,實驗結果顯示, 在較低的反應壓力下可得較高分
子量的共聚酯與聚醚酯，而SnOc 與Ti(OBu) 二種觸媒對聚合反應分子量
的影響不明顯,而聚酯醚其柔軟性及親水性較共聚酯高,使得其水解速率常
數較聚酯大.再將文獻所提PLLA,PEG/ PLLA三團聯共聚物一併考量,得到聚
乳酸系水解速率常數與分子鏈上酯基密度的相關。

Two new types of boidegradable polymer materials, copoly(L-
lactic acid/succinic anhydride/ethylene gl- ycol) and copoly(L-
lactic acid/succinic anhydride/po- lyethylene glycol),was
synthesized by means of direct copolycondensation of EG or PEG(
molar mass=200) with diacid, synthesized from L-lactic acid
and succinic anhydride,in the presence of a Ti(OBu) or SnOc
cata- lyst. The copolymers were characterized by GPC , IR , H-
NMR and contact angle.The first-order kinetics is used to
caculate the rate constants of hydrolysis reaction.The results
indicate that the lower reaction pressure,the higher molecular
weight of copolymers.T- here is no discernible difference
between the Ti(OBu) and SnOc catalysts in polymerization,as
far as mole- cular weight of products and yield of reaction
is concerned. The rate constant for more hydrophilic copoly(
LA/SA/PEG) is higher than copoly(LA/SA/EG).Ta- king into
account the rate constants of PLLA,PEG/PLLA triblock copolymers
in the previous study and copoly- mers in this study that the
rate constants of hydrol- ysis for lactic acid biodegradble
polymers is correl- ated with the ratio of no. of ester to no.
of carbon on main chain.