摘要
聚乳酸(PLA)是一种可再生、可生物降解材料,废弃后能完全生物降解,具有环境友好、拉伸强度高、加工性能优良等特点。然而,PLA的熔体强度低,产品脆性高,在加工时通常需要对PLA进行改性处理。扩链改性是一种有效的方法,可以显著改善PLA的熔体强度,扩大其应用范围。本文中采用甲基丙烯酸缩水甘油酯(GMA)、苯乙烯(St)、甲基丙烯酸甲酯(MMA)和丙烯酸丁酯(BA)为共聚单体,通过悬浮聚合制备了一种多元共聚环氧型扩链剂(R),即GMA-St-MMA-BA共聚物,详细研究了扩链剂R对PLA熔融指数、热稳定性、结晶动力学等性能的影响。结果表明,扩链剂R的引入使PLA结晶温度降低,熔融温度提高,当扩链剂R质量分数为1.5%时,PLA的熔融指数下降了78%。同时,随着R添加量的提高,PLA的断裂行为逐渐由脆性断裂向韧性断裂转变。研究工作为PLA扩链改性提供了一种新思路。
Polylactic acid(PLA)is a renewable and biodegradable material that can be completely biodegraded after disposal.It is environmentally friendly,has high tensile strength,and excellent processing performance.However,PLA has low melt strength and high product brittleness,which often necessitates modification during processing.Chain extension modification is an effective method to significantly improve the melt strength of PLA and expand its application range.In this study,a multicomponent copolymer epoxy-type chain extender(R),namely GMA-St-MMA-BA copolymer,was prepared through suspension polymerization using glycidyl methacrylate(GMA),styrene(St),methyl methacrylate(MMA),and butyl acrylate(BA)as comonomers.The effects of the prepared chain extender R on melt index,thermal stability,crystallization kinetics,and other properties of PLA were investigated in detail.The results show that the introduction of chain extender R lowers the crystallization temperature and increases the melting temperature of PLA.When the mass fraction of chain extender R added is 1.5%,the melt index of PLA is decreased by 78%.Additionally,as the amount of R increases,the fracture behavior of PLA gradually transitions from brittle fracture to ductile fracture.This work provides a new approach for the chain extension modification of PLA.
作者
赵炳安
胡靖涛
李文东
李化毅
刘晓青
孟祥福
Bingan Zhao;Jingtao Hu;Wendong Li;Huayi Li;Xiaoqing Liu;Xiangfu Meng(Department of Chemistry,Capital Normal University,Beijing 100048,China;China Science Advanced Engineering Plastics National Engineering Research Center Co.,Ltd.,Beijing 102206,China;Institute of Chemistry,Chinese Academy of Sciences,Beijing 100190,China)
出处
《高分子材料科学与工程》
北大核心
2025年第11期1-10,共10页
Polymer Materials Science & Engineering
关键词
聚乳酸
扩链剂
环氧基团
悬浮聚合
熔体强度
结晶
polylactic acid
chain extender
epoxy group
suspension polymerization
melt strength
crystallization
