Department of Materials Science and Engineering, Seoul National University, Seoul 08826, Republic of Korea.
Department of Organic Materials and Fiber Engineering, Soongsil University, 369 Sangdo-ro, Dongjak-gu, Seoul 06978, Republic of Korea.
Int J Biol Macromol. 2021 Dec 15;193(Pt B):1103-1113. doi: 10.1016/j.ijbiomac.2021.09.205. Epub 2021 Oct 26.
Increasing the toughness of poly(lactic acid) (PLA), i.e., simultaneously increasing both the tensile strength and ductility, remains a major challenge. In this study, fully bio-based PLA blends with polydecalactone (PDL)-grafted cellulose copolymer (CgPD) were prepared and comprehensively analyzed to enhance the toughness of the PLA matrix. The blends were found by FT-IR and solid-state H NMR to be physically intact and miscible at the sub-twenty-nanometer scale. The WXRD and DSC analyses indicated that the addition of the alkyl-branched CgPD imparts a more structurally disordered PLA mesophase state to the prepared PLA_CgPD bio-blends. UTM analysis was used to characterize the macroscopic mechanical properties of the PLA_CgPD bio-blends. Both the tensile strength and elongation properties were simultaneously improved with the addition of 1 wt% CgPD loading amount to PLA (PLA_CgPD1). This study experimentally demonstrates that the enhanced mechanical properties of PLA_CgPD1 are closely related to the existence of more ordered PLA mesophases induced by the introduction of an optimal amount of CgPD into the PLA matrix.
提高聚乳酸（PLA）的韧性，即同时提高拉伸强度和延展性，仍然是一个主要挑战。在这项研究中，制备了完全基于生物的 PLA 共混物，其中接枝了聚己内酯（PDL）的纤维素共聚物（CgPD），以提高 PLA 基体的韧性。通过傅里叶变换红外光谱（FT-IR）和固态 H 核磁共振（NMR）发现，这些共混物在亚二十纳米的尺度上是物理上完整的，且可混溶的。广角 X 射线衍射（WXRD）和差示扫描量热法（DSC）分析表明，添加支化烷基的 CgPD 会赋予制备的 PLA_CgPD 生物共混物更无序的 PLA 介晶态结构。使用 UTM 分析来表征 PLA_CgPD 生物共混物的宏观机械性能。随着 1wt% CgPD 加入到 PLA（PLA_CgPD1）中，拉伸强度和伸长性能都得到了同时提高。本研究从实验上证明了 PLA_CgPD1 的增强力学性能与引入 PLA 基体中适量 CgPD 诱导的更有序 PLA 介晶相的存在密切相关。
