Department of Chemical Engineering, Kongju National University
*Division of Advanced Materials Engineering, Kongju National University, 1223-24 Cheoandaero, Cheonan, Chungnam 31080, Korea
공주대학교 공과대학 화학공학부, *공주대학교 공과대학 신소재공학부
In this study, Ti(acac)2(O-i-Pr)2 was synthesized by coordinating acetylacetone with Ti metal and L-lactide polymerization was carried out with it to investigate polymerization behaviors. L-lactide polymerization was investigated by comparing Ti(acac)2(O-i-Pr)2 with Ti(acac)3. L-lactide/catalyst molar ratio and polymerization time were changed in the absence of initiator. Ti(acac)2(O-i-Pr)2 showed a high activity from the beginning and exhibited a high conversion, and was more active than the Ti catalysts disclosed in the literature. The molecular weight of poly(lactide) (PLA) produced using Ti(acac)2(O-i-Pr)2 was smaller than that of Ti(acac)3. The reason for the high conversion of Ti(acac)2(O-i-Pr)2 is considered to be that the polymerization reaction proceeds more rapidly than Ti(acac)3 due to the presence of an alkoxy group in the catalyst. Benzyl alcohol as an initiator resulted in an increase in the conversion of Ti(acac)3, but a decrease in the conversion of Ti(acac)2(O-i-Pr)2.
본 연구에서는 아세틸아세톤(acetylacetone)을 Ti 금속에 배위시켜 Ti(acac)2(O-i-Pr)2을 합성하였고 이 촉매의 L-락티드 중합특성을 확인하였다. 이 때 Ti(acac)2(O-i-Pr)2의 중합특성을 Ti(acac)3와 비교하였다. 개시제 없이 L-락티드/촉매 몰비와 중합시간을 변화시켜 진행하였다. Ti(acac)2(O-i-Pr)2가 반응시작부터 큰 활성을 보이며 높은 전환율을 보였고, 기존 문헌에서 발표한 Ti계 촉매보다 활성이 컸다. 분자량은 Ti(acac)2(O-i-Pr)2를 이용하여 생성된 폴리락티드(PLA)의 분자량이 Ti(acac)3보다 작았다. Ti(acac)2(O-i-Pr)2의 전환율이 높은 이유는 촉매 내 알콕시기가 존재하여 Ti(acac)3보다 중합 반응이 더 빠르게 진행되는 것으로 판단된다. 개시제인 벤질 알콜은 Ti(acac)3의 전환율을 증가시키지만, Ti (acac)2(O-i-Pr)2의 전환율은 감소시켰다.
Keywords: L-lactide, poly(lactide), polymerization, Ti(acac)2(O-i-Pr)2
2018; 42(2): 242-248
Published online Mar 25, 2018
Department of Chemical Engineering, Kongju National University, 1223-24 Cheoandaero, Cheonan, Chungnam 31080, Korea