核-壳结构粒子MBS增韧聚乳酸的性能研究

Study on Properties of Core-shell Structure MBS Particles Toughened Polylactide

采用乳液聚合法合成核-壳结构粒子甲基丙烯酸甲酯-丁二烯-苯乙烯共聚物(MBS),进一步对聚乳酸(PLA)进行增韧改性,并以甲基丙烯酸甲酯-甲基丙烯酸缩水甘油酯共聚物P(MMA-co-GMA)作为共混体系的相容剂。通过力学性能测试、动态热机械分析仪、透射电子显微镜、扫描电子显微镜等手段研究了该共混体系的力学性能和微观形态。结果表明,随着MBS含量的增加,共混物的冲击强度显著提高,屈服应力逐渐降低;相容剂P(MMAco-GMA)的引入没有提高共混物的冲击性能,但是显著提高了拉伸强度。DMA结果表明,随着P(MMA-co-GMA)中GMA含量的增加,PLA的玻璃化转变温度逐渐上升,MBS壳层的玻璃化转变温度逐渐降低;TEM测试发现P(MMAco-GMA)加入后,核壳粒子在PLA中分散得更加均匀。对形变区的SEM观察发现MBS橡胶粒子发生空洞化,基体发生剪切屈服。

The core-shell structure particles of methyl methacrylate-butadiene-styrene copolymer （MBS） were prepared via an emulsion polymerization process and was used to toughen polylactide （PLA）.Poly （methyl methacrylate-co-glycidyl methacrylate） [P（MMA-co-GMA）] was used as a compatibilizer.Mechanical properties and morphologies of the blends were studied by mechanical performance test,dynamic mechanical thermal analyzer （DMA）,transmission electron microscope （TEM） and scanning electron microscope （SEM）.The research found that the impact strength of the blends increased significantly and the yielding stress of the blends decreased with the increase of MBS content.The introduction of P（MMA-co-GMA） did not improve the impact property but improved the tensile stress of the PLA blends.DMA results showed,with the increase of GMA content in P（MMA-co-GMA）,the glass transition temperature （Tg） of PLA improved and the Tg of the MBS shell phase decreased.TEM observation indicated that the core-shell particles dispersed in the PLA matrix more uniformly with the addition of P（MMA-co-GMA）.Deformation zone SEM result showed that cavitations of MBS particles and shear yielding of the matrix occurred.