School of Materials Science and Engineering, Jilin Jianzhu University, Changchun 130118, China; Key Laboratory of Polymer Ecomaterials, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, China.
School of Materials Science and Engineering, Jilin Jianzhu University, Changchun 130118, China.
Int J Biol Macromol. 2021 Jun 30;181:60-71. doi: 10.1016/j.ijbiomac.2021.03.127. Epub 2021 Mar 23.
Herein, poly(3-hydroxybutyrate-co-4-hydroxyvalerate) (P34HB), poly (L-lactic acid) (PLA), and poly(vinyl acetate) (PVAc) were initially melt compounded to prepare a ternary blend with balanced properties. Further, the miscibility, phase morphology, thermal and crystallization behaviors, and rheological and mechanical properties of the blends were studied. The dynamic mechanical analysis (DMA) results indicated that P34HB and PLA were partially miscible; however, PVAc showed full miscibility with PLA and P34HB. PVAc would selectively disperse in the PLA phase when considering low content, whereas it would gradually diffuse into the P34HB phase with the increasing PVAc concentration. A phase-separated morphology was observed for all the blends using scanning electron microscopy (SEM), and the diameters of the dispersed phases increased with the increasing PVAc concentration. The crystallization of P34HB was enhanced by the presence of PLA alone and was restrained by the simultaneous incorporation of PVAc and PLA. The rheological properties of P34HB were significantly improved because of the PVAc phase. Unexpectedly, the toughness and stiffness of the P34HB in ternary blends clearly improved because of the incorporation of PLA and PVAc.
本文首先将聚（3-羟基丁酸-co-4-羟基丁酸酯）（P34HB）、聚（L-乳酸）（PLA）和聚醋酸乙烯酯（PVAc）熔融共混，制备性能平衡的三元共混物。进一步研究了共混物的相容性、相形态、热和结晶行为以及流变和力学性能。动态力学分析（DMA）结果表明，P34HB 和 PLA 部分相容；然而，PVAc 与 PLA 和 P34HB 完全相容。考虑到低含量时，PVAc 会选择性地分散在 PLA 相中，而随着 PVAc 浓度的增加，它会逐渐扩散到 P34HB 相中。扫描电子显微镜（SEM）观察到所有共混物均呈现相分离形态，分散相的直径随 PVAc 浓度的增加而增大。单独添加 PLA 可增强 P34HB 的结晶，同时添加 PVAc 和 PLA 会限制其结晶。由于存在 PVAc 相，P34HB 的流变性能得到显著改善。出乎意料的是，由于 PLA 和 PVAc 的加入，三元共混物中 P34HB 的韧性和刚性明显提高。
