3 D打印用聚氯乙烯多相复合体系的开发

采用高分子类增塑剂乙烯-乙酸乙烯酯共聚物（EVM）替代聚氯乙烯（PVC）传统增塑剂，制备出具有双连续相结构的PVC/EVM/聚乳酸（PLA）共混物。通过热分析、流变学测试及微观形貌观察等研究了共混物结构与性能间的关系。结果表明，随着填料蒙脱土（OMMT）或碳纳米管的加入，PVC/EVM/PLA共混物的热分解温度和体系燃烧后的剩余物均逐渐增加，黏度略微增大且入口压力降有所减小，对玻璃化转变温度影响不大，但使得最大冷结晶温度有所升高，并且有效改善了PVC与EVM和PVC与PLA界面间的结合强度，提高了共混物的冲击强度，尺寸稳定性亦有所改善。结合打印制品外观和尺寸稳定性两方面考虑，最佳的3 D打印材料配方体系宜为PVC/EVM/PLA/OMMT-2。

Development of polyvinyl chloride multiphase composite for 3D printing

Polyvinyl chloride(PVC)/ethylene vinyl acetate copolymer(EVM)/polylactic acid(PLA)blends with bi-continuous structure were prepared by using EVM instead of traditional plasticizer of PVC.The relationship between structure and properties of the blends was studied by thermal analysis,rheological test and micro morphology observation.The results showed that with the addition of montmorillonite(OMMT)or carbon nanotubes,the thermal decomposition temperature of PVC/EVM/PLA blends and residue after combustion increased gradually,the viscosity increased slightly and inlet pressure drop decreased.The glass transition temperature was not significantly affected,but the maximum cold crystallization temperature increased,and the bonding strength between PVC and EVM and between PVC and PLA were effectively improved,the impact strength and dimensional stability of the blends were also improved.Considering the appearance and dimensional stability of printed products,the best formulation system of 3 D printing materials was PVC/EVM/PLA/OMMT-2.