反应挤出法制备聚乙丙交酯及其热性能  

Preparation of poly(glycolide-co-L-lactide)continuously by reactive extrusion and its thermal properties

作　　者：王睿[1] 周芬[1] 周文乐[1] Wang Rui;Zhou Fen;Zhou Wenle(Sinopec Shanghai Research Institute of Petrochemical Technology,Shanghai 201208,China)

机构地区：[1]中国石化上海石油化工研究院,上海201208

出　　处：《石油化工》2020年第9期869-875,共7页Petrochemical Technology

基　　金：中国石油化工股份有限公司资助项目(213027)。

摘　　要：以双螺杆挤出机为反应器通过乙交酯和L-丙交酯的开环共聚制备了聚乙丙交酯(PGLA),探讨了催化剂用量、聚合温度及螺杆转速等因素对聚合的影响,并采用调制式差示扫描量热分析(MDSC)法详细研究了PGLA在相变过程中的热性能。实验结果表明,在催化剂用量为300×10^-6(w)、聚合温度为200℃、螺杆转速为10 r/min的适宜工艺条件下可获得重均相对分子质量大于1.0×10^5的PGLA,在140℃下真空加热8 h可将残留单体含量降至2%(w)以下,并保持较高的相对分子质量。通过MDSC的不可逆曲线可有效分辨PGLA在熔融过程中发生的微量聚乳酸均聚物的重结晶和PGLA晶体完善等相变;随着升温速率的提高和调制周期的延长,熔融峰分割在可逆曲线上的比例呈逐渐增加的趋势,不可逆曲线上重结晶放热峰的积分面积也逐渐增大。Direct preparation of poly(glycolide-co-L-lactide)(PGLA)by ring-opening polymerization of glycolide and L-lactide using twin-screw extruder was carried out.The impact of the catalyst content,the polymerization temperature and the screw speed on polymer properties was studied.Modulated differential scanning calorimetry(MDSC)was also used to study the thermal performance of PGLA in the phase transition process in detail.The result shows that PGLA with a weight average molecular weight greater than 1.0×10^5 can be obtained under suitable conditions with a catalyst dosage of 300×10^-6(w),a polymerization temperature of 200℃,and a screw speed of 10 r/min.Further adopting a process of vacuum heating at 140℃for 8 h can reduce the monomer residue of PGLA to less than 2%(w)and maintain a high molecular weight.By means of the irreversible curve of MDSC,the recrystallization of trace polylactic acid homopolymer and crystal perfection of PGLA can be effectively distinguished,which both occur during the melting process of PGLA.With the increase of heating rate and modulation period,the proportion of melting peak division on the reversing curve gradually increases,and the integral area of the recrystallization exothermic peak on the nonreversing curve also increases.

关 键 词：聚乙丙交酯 反应挤出 开环聚合 调制式差示扫描量热分析法 

分 类 号：TQ325.1[化学工程—合成树脂塑料工业]