左旋聚乳酸/右旋聚乳酸立构复合晶体形状记忆聚合物的制备与性能  

Preparation and Properties of Poly-L-Lactide/Poly-D-Lactide Stereocomplex Shape Memory Polymers

作　　者：刘天宇 高琪琪 Tianyu Liu;Qiqi Gao(College of Chemistry and Materials Science,Jinan University,Guangzhou 510632,China)

机构地区：[1]暨南大学化学与材料学院,广东广州510632

出　　处：《高分子材料科学与工程》2021年第3期176-183,共8页Polymer Materials Science & Engineering

基　　金：广东省基础与应用基础研究基金项目(2020A1515011005);广东省国际科学研究合作项目(2021A0505030037)

摘　　要：通过环保高效的熔融共混在左旋聚乳酸(PLLA)中引入少量的右旋聚乳酸(PDLA),使得聚乳酸立构复合晶体(sc-PLA)在PLLA基体中原位形成并均匀分散,制备得到全生物可降解的聚乳酸形状记忆聚合物(SMPs)功能材料。当仅向PLLA基体中加入1%PDLA时,就可使得sc-PLA晶体在PLLA中原位形成,且随着PDLA含量的不断增加,sc-PLA晶体的含量也不断增加。动态力学测试结果表明,sc-PLA晶体几乎不影响PLLA/PDLA共混材料的玻璃化转变温度,却可提高PLLA的高温段模量。形状记忆性能测试表明,PLLA和PLLA/PDLA共混材料均具有极佳的形状固定率(Rf≈100%),而PLLA/PDLA共混材料形状回复率Rr随着PDLA含量的增加呈现先增加后下降的趋势。当PDLA质量分数为3%时,PLLA/PDLA共混材料的形状记忆回复率(Rr)达到最佳(Rr≈85.31%),且进一步的测试表明PLLA/3PDLA共混材料的形状记忆性能在多次同等条件重复测试后仍能持续保持。With the increasing scarcity of petroleum resources and the continuous deterioration of global environment due to the extensive application of petroleum-based polymers,the development of shape memory polymer functional materials based on green and sustainable biopolymers have attracted increasing attention.In this study,via facile and environmental melt blending,the incorporation of PDLA into PLLA matrix gives rise to the in-situ formation of polylactide stereocomplex(sc-PLA),and the homogeneous dispersion of sc-PLA enhances the shape memory performance of PLLA,consequently obtaining the totally biodegradable PLA-based shape memory functional materials.With the incorporation of only 1%PDLA into PLLA matrix,the in-situ formation of sc-PLA is achieved and the sc-PLA content increases with the increasing PDLA content.The thermal-mechanical results indicate that the formation of sc-PLA has few influence on glass transition temperature of PLLA/PDLA blends and can enhance the strorage modulus at the high temperature effectively.And the shape memory results manifest that both pure PLLA and PLLA/PDLA blends with various composition ratios represent excellent shape fixing performance(Rf≈100%),but the value of the shape recovery ratio of PLLA/PDLA blends is increased firstly and then decreased with the increasing PDLA content.When the PDLA mass fraction reaches to 3%,the PLLA/PDLA blend obtain the optimal shape memory performance(Rr≈85.31%),and the shape memory performance of PLLA/3PDLA blends can keep constantly even after repeated shape memory tests under the invariable test condition.In conclusion,the biodegradable PLA-based shape memory functional materials have been successfully achieved via simple and facile melting blend,and the application of sc-PLA as physical network point in shape memory functional materials can be broaden,consequently offering a new strategy to the structure design of PLA-based shape memory functional materials.

关 键 词：聚乳酸立构复合晶体 左旋聚乳酸 右旋聚乳酸 形状记忆性能 生物可降解 

分 类 号：TQ323.3[化学工程—合成树脂塑料工业]