CAJ | 학술논문

在微波辅助下,以辛酸亚锡为催化剂、壳聚糖(CS)为大分子引发剂引发消旋丙交酯(D,L-LA)本体开环聚合制备了壳聚糖接枝聚乳酸共聚物. 通过正交试验确定了最佳合成条件:微波功率10 W,反应温度120 ℃,反应时间15 min,催化剂用量:n(丙交酯):n(辛酸亚锡)=1 000:1. 通过红外光谱、元素分析、核磁共振氢谱、X射线衍射和热分析测试技术对接枝共聚物的结构与性能进行了表征和测试. 结果表明,在微波条件下,能快速、有效地合成壳聚糖接枝聚乳酸共聚物,单位糖环上聚乳酸支链的平均乳酰单元数大于17.46;聚乳酸支链的引入有效削弱了壳聚糖分子间和分子内较强的氢键作用,与壳聚糖相比较,共聚物的结晶性能下降,热分解发生在246 ℃,低于壳聚糖的253 ℃;随n(D,L-LA)/n(CS糖环数)值增大,共聚物中平均乳酰单元数逐渐增大,共聚物的结晶性能、起始分解温度逐渐下降.
재미파보조하,이신산아석위최화제、각취당(CS)위대분자인발제인발소선병교지(D,L-LA)본체개배취합제비료각취당접지취유산공취물. 통과정교시험학정료최가합성조건:미파공솔10 W,반응온도120 ℃,반응시간15 min,최화제용량:n(병교지):n(신산아석)=1 000:1. 통과홍외광보、원소분석、핵자공진경보、X사선연사화열분석측시기술대접지공취물적결구여성능진행료표정화측시. 결과표명,재미파조건하,능쾌속、유효지합성각취당접지취유산공취물,단위당배상취유산지련적평균유선단원수대우17.46;취유산지련적인입유효삭약료각취당분자간화분자내교강적경건작용,여각취당상비교,공취물적결정성능하강,열분해발생재246 ℃,저우각취당적253 ℃;수n(D,L-LA)/n(CS당배수)치증대,공취물중평균유선단원수축점증대,공취물적결정성능、기시분해온도축점하강.
Chitosan-graft-poly(D,L-lactide)(CS-g-PLA) copolymers were obtained by means of microwave-irradiation and graft copolymerization via ring opening polymerization using stannous octoat(Sn(oct)_2) as catalyst without any organic solvent. Through orthogonality experiment the best synthesis conditions were optimized as follows:reaction power 10 W, reaction temperature 120 ℃, reaction time 15 min, the amount of catalyst n(lactide)∶ n(Sn(oct)_2)=1 000∶ 1. The products were characterized by FTIR, ~1H NMR, XRD and DTG. These results show that microwave-assisted ring-opening polymerization can produce a CS-g-PLA copolymer successfully and rapidly. The average degree of polymerization of polylactide branch chains in the graft copolymer was 17.46. Compared with CS, the grafting destroyed the original crystallinity of chitosan, and the onset temperature of degradation and thermal stability of the products descended. The feed ratio n(D,L-LA)/n(aminoglucoside) had a strong influence on the structure and properties of the CS-g-PLA copolymer, and higher feed ratio led to the copolymer with a higher average degree of polymerization of polylactide branch chains, and a lower crystallinity and an onset temperature(246 ℃) of degradation, lower than that of CS of 253 ℃.