Ethylene-vinyl acetate–glycidyl methacrylate random terpolymer (EVM–GMA, VA = 60 wt%, GMA = 2.9%) was used as a polymeric plasticizer replacing the traditional dioctyl phthalate (DOP) to prepare a polyvinyl chloride (PVC) masterbatch. Polylactic acid (PLA) was applied to blend with the PVC masterbatch in melt to examine the epoxy ring-opening reactions between epoxy groups in EVM–GMA and end carboxyl groups in PLA in order to construct a special phase structure in PVC/PLA improving the mechanical properties and 3D printing performance. The formation and evolution of phase structures were revealed by aids of the unique rheological responses of multi-component composite system. The results showed that with the increase in EVM–GMA content, the phase morphology of PVC/PLA was refined from co-continuous phase structure to denser one and then evolved to sea-island structure. It was also found that the addition of EVM–GMA inhibited the crystallization of PLA and the cold crystallization as well. When PVC/EVM–GMA/PLA was incorporated in weight ratio of 45/5/50, the denser co-continuous phase structure with smaller domain imparted the composite a highest zero shear viscosity and viscous flow activation energy. This unique structure existed stably when the shear rate was less than 230 s−1 or below 180 °C. Consequently, it endowed composite the highest impact strengths and smoothest appearance of 3D printed specimens. Therefore, moderate EVM–GMA is not only a reliable alternative plasticizer for PVC, but also an ideal modifier for the compatibility of PVC/PLA blends which presented an excellent performance in 3D printing.

中文翻译：

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用于 3D 打印的多相复合材料的结构和演变

乙烯-乙酸乙烯酯-甲基丙烯酸缩水甘油酯无规三元共聚物（EVM-GMA，VA = 60 wt%，GMA = 2.9%）用作聚合物增塑剂，取代传统的邻苯二甲酸二辛酯（DOP）制备聚氯乙烯（PVC）母料。将聚乳酸 (PLA) 与熔融的 PVC 母料共混，以检查 EVM-GMA 中的环氧基与 PLA 中的末端羧基之间的环氧开环反应，以在 PVC/PLA 中构建特殊的相结构，从而改善力学性能和 3D 打印性能。借助多组分复合体系独特的流变响应，揭示了相结构的形成和演变。结果表明，随着 EVM-GMA 含量的增加，PVC/PLA 的相形态从共连续相结构细化为致密相结构，然后演变为海岛结构。还发现 EVM-GMA 的加入抑制了 PLA 的结晶和冷结晶。当 PVC/EVM-GMA/PLA 以 45/5/50 的重量比掺入时，更致密的共连续相结构和较小的域赋予复合材料最高的零剪切粘度和粘性流动活化能。当剪切速率小于 230 s-1 或低于 180 °C 时，这种独特的结构稳定存在。因此，它赋予复合材料最高的冲击强度和最光滑的 3D 打印样品外观。因此，适度的 EVM-GMA 不仅是 PVC 的可靠替代增塑剂，