尼龙及增容剂对聚氯乙烯木塑复合材料性能的影响

PVC木塑复合材料中添加低熔点尼龙,并引入3种增容剂:马来酸酐接枝EVA(EVA-g-MAH)、马来酸酐接枝聚丙烯(PP-g-MAH)和马来酸酐接枝POE(POE-g-MAH),以提高材料的性能。力学性能测试显示:尼龙及增容剂的添加提高了PVC木塑复合材料的力学性能。其中,EVA-g-MAH的使用效果最为明显,复合材料的冲击强度提高了39.02%,弯曲强度提高了16.37%。动态力学性能测试表明:添加低熔点尼龙及增容剂,不同程度地降低了复合材料的储能模量。转矩流变性能测试表明:低熔点尼龙降低了复合材料的平衡转矩。而EVA-gMAH及POE-g-MAH提高了尼龙-PVC复合材料的平衡转矩,对材料的加工性有不利的影响。扫描电镜分析表明:加入增容剂后,复合材料界面不同程度发生钝化,复合材料相容性提高。吸水率测试结果表明:低熔点尼龙的加入提高了PVC复合材料的吸水率,而增容剂对降低材料吸水率有明显作用。

Effect of Low Melting Point Nylon and Compatibilizer on the Properties of PVC Plastic Composites

In order to improve the toughness of wood flour-polyvinyl chloride composites (WF-PVC), low melting point of nylon and three kinds of compatibilizers, maleic anhydride grafted EVA (EVA-g-MAH), maleic anhydride grafted polypropylene (PP-g-MAH) and maleic anhydride grafted POE (POE-g-MAH) were introduced to the preparation process of the composites.The addition of low melting point nylon and compatibilizer increased mechanical properties of WF-PVC composites, the impact strength of WF-PVC composite increased by 18.76% for the incorporation of low melting point nylon, the flexural strength was increased by 13.65%.Nylon-WF-PVC composites with EVA-g-MAH compatibilizer present much higher mechanical characteristic, the impact strength of the composite was increased by 39.02% and the flexural strength was increased by 16.37%.The dynamic mechanical analysis test showed that the addition of low melting point nylon and compatibilizer reduced the storage modulus of the composites, especially in 30℃-90℃.The torque rheometer test results showed that the balance torque of WF-PVC composites was decreased due to the addition of low melting nylon.In contrast, the incorporation of EVA-g-MAH and POE-g-MAH increased the balance torque.The torque rheometer results indicated compatibilizers had some negative effects on the processing properties of WF-PVC composites.SEM images showed EVA-g-MAH and POE-g-MAH were effective compatibilizers to nylon and WF-PVC blends and could decrease the particle size of nylon on continuous phase of WF-PVC, and thus enhance the mechanical properties of WF-PVC composites obviously.Water absorption test results showed that the water absorption of WF-PVC increased with the addition of low melting nylon.The water absorption of the Nylon-WF-PVC was increased by compatibilizer.