Liu Zhe, Qiu Ying, Wang Xiaoguang, Bai Xiaohan, Song Yu, Yang Bing, Yu Lingxiao, Huang Jiangting, Leng Siying, Gao Jialu, Gao Guangxu, Zhao Ziyi, Li Yongchao, Hao Yongsheng, Wang Yuanxia, Song Lixin
Liaoning Provincial Key Laboratory for Synthesis and Preparation of Special Functional Materials, Shenyang University of Chemical Technology, Shenyang 110142, Liaoning, China; College of Materials Science and Engineering, Shenyang University of Chemical Technology, Shenyang 110142, China.
College of Chemistry, Jilin University, Changchun 130012, China.
Int J Biol Macromol. 2025 May;310(Pt 3):143400. doi: 10.1016/j.ijbiomac.2025.143400. Epub 2025 Apr 21.
With the increasing severity of the "white pollution" problem caused by the excessive use of plastic products, the application of biodegradable materials and the recycling of plastic waste can help alleviate environmental burdens. In this study, a series of polylactic acid/functionalized recycled polyolefin blends (PLA/(R-LLDPE/POE)-g-(GMA-co-St), abbreviated as PLA/RPGS) were prepared via free-radical melt grafting. The effects of RPGS content on the crystallinity, rheological behavior, optical properties, thermal and mechanical properties, as well as the microstructure of the PLA/RPGS blends were systematically investigated. The results indicate that the prepared RPGS exhibits excellent toughening effects on PLA resin. The introduction of glycidyl methacrylate (GMA) and styrene (St) significantly enhances the compatibility between PLA and recycled LLDPE/POE (hereinafter referred to as RP), thereby markedly improving the thermal performance and flexibility of the PLA/RPGS blends while maintaining excellent optical properties. With increasing RPGS content, the entanglement within the blend system becomes more compact, resulting in gradual increases in G', G", and η, while the thermal stability first improves and then tends to stabilize. A more complex three-dimensional network crosslinked structure is formed within the blend system, which restricts the mobility of PLA chains, leading to a gradual decrease in the degree of crystallinity (X) of the blends. The notched impact strength and elongation at break of the blends progressively increase, with more pronounced ductile fracture features observed on the impact fracture surfaces, indicating a transition from brittle to ductile fracture behavior. When the RPGS content reaches 20 wt%, the haze of the blend decreases to 28.3 %, while the transmittance, T, T, and Vicat softening temperature increase to 92.2 %, 339.97 °C, 368.12 °C, and 78.2 °C, respectively. At this composition, the notched impact strength and elongation at break reach 10,182.4 J/m and 231.75 %, respectively, representing the optimal overall performance of the blends.
随着塑料制品过度使用所导致的“白色污染”问题日益严重，可生物降解材料的应用以及塑料废弃物的回收利用有助于减轻环境负担。在本研究中，通过自由基熔融接枝制备了一系列聚乳酸/功能化回收聚烯烃共混物（聚乳酸/（线性低密度聚乙烯/聚烯烃弹性体）-g-（甲基丙烯酸缩水甘油酯-共-苯乙烯），简称为聚乳酸/RPGS）。系统研究了RPGS含量对聚乳酸/RPGS共混物的结晶度、流变行为、光学性能、热性能和力学性能以及微观结构的影响。结果表明，所制备的RPGS对聚乳酸树脂具有优异的增韧效果。甲基丙烯酸缩水甘油酯（GMA）和苯乙烯（St）的引入显著增强了聚乳酸与回收线性低密度聚乙烯/聚烯烃弹性体（以下简称RP）之间的相容性，从而在保持优异光学性能的同时，显著提高了聚乳酸/RPGS共混物的热性能和柔韧性。随着RPGS含量的增加，共混体系内的缠结变得更加紧密，导致G'、G''和η逐渐增加，而热稳定性先提高后趋于稳定。共混体系内形成了更复杂的三维网络交联结构，这限制了聚乳酸链的流动性，导致共混物的结晶度（X）逐渐降低。共混物的缺口冲击强度和断裂伸长率逐渐增加，在冲击断面上观察到更明显的韧性断裂特征，表明其断裂行为从脆性转变为韧性。当RPGS含量达到20 wt%时，共混物的雾度降至28.3%，而透光率、T、T和维卡软化温度分别提高到92.2%、339.97℃、368.12℃和78.2℃。在此组成下，缺口冲击强度和断裂伸长率分别达到10182.4 J/m和231.75%，代表了共混物的最佳综合性能。
