Toward ultra-tough and heat-resistant biodegradable polylactide/core-shell rubber blends by regulating the distribution of rubber particles with stereocomplex crystallites
Toward ultra-tough and heat-resistant biodegradable polylactide/core-shell rubber blends by regulating the distribution of rubber particles with stereocomplex crystallites
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通过立体复合微晶调节橡胶颗粒的分布，开发超坚韧、耐热、可生物降解的聚丙交酯/核壳橡胶共混物
DOI：
10.1016/j.ijbiomac.2023.123422
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发表时间：
2023
影响因子：
8.2
通讯作者：
Dongyu Bai
中科院分区：
文献类型：
--
作者：
Huili Liu;Yaling Zhao;Yushan Zheng;Jianyang Chen;Jianchuan Wang;Guangyong Gao;Dongyu Bai
利用立构复合物（SC）微晶有效调控核壳橡胶（CSR）在聚乳酸（PLLA）基体中的分布，制备了超韧耐热的PLLA/CSR共混物。合成了线型和3-11臂聚乳酸（PDLA），并与PLLA/CSR共混物熔融共混。在PLLA/PDLA/CSR共混体系中，引入的PDLA链可以与PLLA链协同作用形成致密的SC微晶网络，从而诱导CSR粒子由均匀分布结构向网络状结构转变。随着PDLA臂数的增加，类网络结构中CSR团簇的尺寸先增大后减小，类网络结构的连续性先保持在较高水平后明显降低。与PLLA/CSR共混物相比，CSR网络状结构的形成在不降低PLLA/PDLA/CSR共混物强度和模量的前提下，显著提高了PLLA/PDLA/CSR共混物的冲击强度，且CSR网络状结构中CSR团簇尺寸较大、连续性较好，有助于获得较高的冲击强度（78.3 kJ/m2）。此外，SC微晶网络和CSR网络状结构也能显著提高PLLA/PDLA/CSR共混物的耐热性（最高维卡软化温度为131 °C）。本工作为控制橡胶网络状形貌从而制备高性能PLLA材料提供了一种有效的策略。
Ultra-tough and heat-resistant poly(l-lactide)/core-shell rubber (PLLA/CSR) blends were fabricated by utilizing stereocomplex (SC) crystallites to effectively regulate the CSR distribution in PLLA matrix. Linear and 3–11 armed poly(d-lactide)s (PDLAs) were synthesized and then melt-mixed with PLLA/CSR blend. Interestingly, the incorporated PDLA chains could collaborate with PLLA chains to form dense SC crystallites network in PLLA/PDLA/CSR blends, thus inducing the CSR particles to transform from uniform distribution structure to network-like structure. With increasing the PDLA arm numbers, the size of CSR clusters in the network-like structure first increased and then decreased, and the continuity of the network-like structure first remained at a high level and then decreased obviously. The formation of CSR network-like structure could remarkably improve the impact strength of PLLA/PDLA/CSR blends without deteriorating their strength and modulus (compared with PLLA/CSR blend), and the CSR network-like structure with larger-sized CSR clusters and higher continuity could help obtain higher impact strength (78.3 kJ/m2). Moreover, the heat resistance of PLLA/PDLA/CSR blends could also be significantly improved (the highest Vicat softening temperature was 131 °C) by the SC crystallites network and CSR network-like structure. This work provides an effective strategy for controlling the rubber network-like morphology and thereby preparing high-performance PLLA materials.