【摘要】 为降低二醋酸纤维素(CDA)的玻璃化转变温度并提高其塑化能力,通过开环共聚方法,以L-丙交酯为接枝单体,以CDA为骨架,在辛酸亚锡的催化下制备二醋酸纤维素接枝聚乳酸(CDA-g-PLA)共聚物,并考察L-丙交酯与CDA投料比(x)对CDA-g-PLA的化学结构、玻璃化转变温度(Tg)和热稳定性的影响。结果表明:聚乳酸链段被成功接枝到二醋酸纤维素骨架上;CDA-g-PLA的T_g和热稳定性随着x的增加而降低;综合考虑CDA-g-PLA的热性能,最终确定L-丙交酯与CDA的最优投料比为4∶1,此时,聚乳酸的接枝率为42%,与CDA相比,CDA-g-PLA的T_g由195℃降到86℃,初始分解温度由345℃降低到250℃,热稳定性良好。更多还原

【Abstract】 In order to reduce the glass transition temperature of cellulose diacetate(CDA) and improve the plasticizing capacity of CDA, the copolymer of cellulose diacetate graft polylactic acid(CDA-g-PLA) was synthesized by ringopening copolymerization with L-lactide as graft monomer and CDA as skeleton under the catalysis of stannous octanoate. The effects of the feeding ratio(x) of L-lactide to CDA on the structure, glass transition temperature(Tg) and thermal stability of CDA-g-PLA were studied. The results showed that the PLA chain segment was successfully grafted to CDA skeleton. The Tgof CDA-g-PLA decreased with the increase of x. Considering the thermal properties of CDA-g-PLA, the optimal feed ratio of L-lactide to CDA was finally determined to be 4 ∶ 1, and the grafting degree of PAL was 42%, compared with CDA, the Tgof CDA-g-PLA was dropped from 195 ℃ to 86 ℃,the initial decomposition temperature was reduced from 345 ℃ to 250 ℃, and the thermal stability was better.更多还原