铝酸酯偶联剂改性纳米云母粉对PLA/PBAT体系的影响

Effect of Aluminate Coupling Agent Modified Nano-MICA Powder on PLA/PBAT System

文章采用聚乳酸(PLA)、聚己二酸丁二醇酯-共对苯二甲酸酯(PBAT)和铝酸酯偶联剂改性的纳米云母粉,通过熔融共混制备了纳米复合薄膜。通过傅里叶变换红外光谱仪(FTIR)、水蒸气透过率测试仪、氧气透过率测试仪、TG-DSC联用同步热分析仪表征纳米复合薄膜的性能。通过总迁移实验和气相色谱-质谱(GC-MS)测定纳米复合材料的特定迁移,评估了纳米复合材料的安全性。结果表明:铝酸酯偶联剂成功活化了纳米云母粉。改性纳米云母粉可以提高PLA的玻璃化转变温度,而PLA的结晶度先升高后降低,添加0.2%改性纳米云母粉效果最佳。PLA/PBAT体系的热稳定性随着改性纳米云母粉添加量的增加而略有下降。加入0.2%改性纳米云母粉使薄膜的水蒸气透过系数降低了28%。纳米云母粉的加入增强了薄膜的界面粗糙度,加入改性纳米云母粉后仍能满足作为食品接触材料的安全要求。

Nanocomposite films were prepared by melting and blending nano-MICA powder modified with polylactic acid(PLA),polybutylene adipate-co-terephthalate(PBAT)and aluminate coupling agent.The properties of nanocomposite films were characterized by a Fourier transform infrared spectroscopy(FTIR),a water vapor transmittance tester,an oxygen transmittance tester,and TG-DSC synchronous thermal analysis instrument.The safety of nanocomposites was evaluated by total migration experiments and gas chromatography-mass spectrometry(GC-MS)to determine the specific migration of nanocomposites.The results show that the aluminate coupling agent successfully activates the nano-MICA powder.The glass transition temperature of PLA can be increased by modified nano-MICA powder,while the crystallinity of PLA first increases and then decreases,and the addition of 0.2%modified nano-MICA powder has the best effect.The thermal stability of the PLA/PBAT system decreases slightly with the increase of the amount of modified nano-MICA powder.The addition of 0.2%modified nano-MICA powder reduced the water vapor transmission coefficient of the film by 28%.The addition of nano-MICA powder enhances the interface roughness of the film,and the addition of modified nano-MICA powder can still meet the safety requirements as a food contact material.