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为提高聚乳酸(PLA)/淀粉共混物界面作用和降低成本,引入甲基丙烯酸缩水甘油酯(GMA)接枝聚乳酸和塑化淀粉(TPS),通过挤出和注射成型制备接枝聚乳酸/塑化淀粉共混物(PLA-g-GMA/TPS)。红外光谱分析证实,GMA成功接枝到PLA分子链上。对共混物的力学性能、热机械性能、微观形貌、热性能及亲水性等进行了系统研究,结果表明,选择GMA用量为6%(接枝率为1.51%)和TPS用量为10%时的拉伸强度、断裂伸长率及弹性模量最佳,分别为42.6MPa、8.9%及260MPa。FE-SEM观察结果表明,低含量TPS中颗粒被基体包覆或嵌入,界面平整,界面结合力强。DMA和DSC结果显示,不同质量配比的PLA-g-6%GMA/TPS共混物的Tg、储存模量、结晶度、结晶温度及熔融温度仅在小范围内发生变化。吸水率和接触角结果表明,低含量TPS的共混物吸水率和接触角变化幅度均小于高含量TPS体系。
In order to improve the interfacial interaction and reduce the cost of polylactic acid (PLA) / starch blends, glycidyl methacrylate (GMA) was introduced into polylactic acid and plasticized starch (TPS) to prepare graft poly Lactic acid / plasticized starch blend (PLA-g-GMA / TPS). Infrared spectroscopy confirmed that GMA successfully grafted to the PLA molecular chain. The mechanical properties, thermomechanical properties, microstructure, thermal properties and hydrophilicity of the blends were systematically studied. The results showed that the dosage of GMA was 6% (the grafting rate was 1.51%) and the amount of TPS was 10 % Of the tensile strength, elongation at break and the best elastic modulus, respectively 42.6MPa, 8.9% and 260MPa. The results of FE-SEM observation showed that particles with low content of TPS were coated or embedded in the substrate, the interface was smooth and the interface was strong. The results of DMA and DSC show that the Tg, storage modulus, crystallinity, crystallization temperature and melting temperature of PLA-g-6% GMA / TPS blends with different mass ratios vary only in a small range. The results of water absorption and contact angle showed that the change of water absorption and contact angle of blends with low content of TPS were both less than those with high content of TPS.