Department of Materials Science and Engineering, National University of Singapore, 9 Engineering Drive 1, Singapore, 117576, Singapore.
Institute of Materials Research and Engineering, Agency for Science, Technology and Research (A*STAR), 3 Research Link, Singapore, 117602, Singapore.
Macromol Rapid Commun. 2019 Mar;40(5):e1800047. doi: 10.1002/marc.201800047. Epub 2018 May 17.
Strength and toughness are the two most important prerequisites for structural applications. Unfortunately, these two properties are often in conflict in materials. Here, an effective and yet practical strategy is proposed to simultaneously strengthen and toughen poly(l-lactide) (PLLA) using a simple rigid-rubber "reinforcing element." This element consists of a rigid graphene oxide (GO) sheet covalently coupled with poly(caprolactone-co-lactide) (PCLLA) rubbery layers, which can be easily synthesized and incorporated into PLLA matrix to develop composites with well-tailored GO/PLLA interfaces. It is demonstrated that by adding the "reinforcing element," i.e., GO-graft-rubber-graft-polyd-lactide), PLLA exhibits higher strength and higher toughness, which could be attributed to the synergy of rigid GO and rubbery PCLLA working in tandem during deformation. It is further demonstrated that this strategy can also be applied to other filler systems, such as clay and particulate polyhedral oligomeric silsesquioxane, and other polymer systems, such as poly(methyl methacrylate). The strategy could be considered as a general design principle for reinforcing materials where both strength and toughness are the key concerns.
强度和韧性是结构应用最重要的两个前提条件。不幸的是，这两种性能在材料中往往相互矛盾。在这里，提出了一种有效且实用的策略，通过使用简单的刚性橡胶“增强元件”同时增强和增韧聚（L-丙交酯）（PLLA）。该元件由共价偶联聚（己内酯-丙交酯）（PCLLA）橡胶层的刚性氧化石墨烯（GO）片组成，可轻松合成并掺入 PLLA 基质中，以开发具有良好 GO/PLLA 界面的复合材料。结果表明，通过添加“增强元件”，即 GO-接枝-橡胶-接枝-聚丙交酯，PLLA 表现出更高的强度和更高的韧性，这可以归因于刚性 GO 和橡胶 PCLLA 在变形过程中的协同作用。进一步证明，该策略也可应用于其他填充体系，如粘土和多面体低聚倍半硅氧烷颗粒，以及其他聚合物体系，如聚甲基丙烯酸甲酯。该策略可被视为增强材料的通用设计原则，其中强度和韧性是关键关注点。
