School of Materials Science and Engineering, Changchun University of Technology, Changchun 130012, China; Key Laboratory of Polymer Ecomaterials, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, China.
Sinopec-SK (Wuhan) Petrochemical Company Limited, Wuhan 430000, China.
Int J Biol Macromol. 2021 Jul 31;183:1871-1880. doi: 10.1016/j.ijbiomac.2021.05.177. Epub 2021 Jun 1.
Poly(L-lactic acid) (PLLA) blends with excellent low-temperature toughness and strength were prepared by melt compounding with acrylic ester based impact resistance agent (AEIR). The morphology, thermal properties, mechanical properties and biodegradability of the blends were investigated. Morphology observations revealed the blend was immiscible but had good compatibility with the dispersed phase size of about 200-300 nm. With the addition of AEIR, dramatic improvement in toughness of PLLA was achieved in a wide temperature range, especially at low temperatures the tensile strength was effectively remained. For the blend with 20 wt% AEIR, the tensile strength, elongation at break and impact strength were 51.6 MPa, 72% and 77.1 KJ/m at -20 °C, respectively, much greater than that reported. The calculated T of AEIR was lower than the test temperatures, and the brittle-tough transition occurred. The PLLA matrix demonstrated obvious shear yielding which induced energy dissipation and therefore lead to excellent toughness of the blends. Moreover, the biodegradation of PLLA was enhanced after blends preparation.
采用丙烯酸酯类抗冲改性剂（AEIR）熔融共混制备了具有优异低温韧性和强度的聚 L-乳酸（PLLA）共混物。研究了共混物的形态、热性能、力学性能和生物降解性。形貌观察表明，共混物为不混溶体系，但具有良好的分散相尺寸相容性，约为 200-300nm。随着 AEIR 的加入，PLLA 的韧性在很宽的温度范围内得到了显著提高，特别是在低温下，拉伸强度得到了有效保持。对于添加 20wt%AEIR 的共混物，在-20°C 时，拉伸强度、断裂伸长率和冲击强度分别为 51.6MPa、72%和 77.1KJ/m，远远大于报道值。AEIR 的计算 T 低于测试温度，发生脆韧转变。PLLA 基体表现出明显的剪切屈服，导致能量耗散，从而使共混物具有优异的韧性。此外，共混物制备后，PLLA 的生物降解性得到增强。
