A novel aryl hydrazide nucleator to effectively promote stereocomplex crystallization in high-molecular-weight poly(L-lactide)/poly (D-lactide) blends
A novel aryl hydrazide nucleator to effectively promote stereocomplex crystallization in high-molecular-weight poly(L-lactide)/poly (D-lactide) blends
复制标题
一种新型芳基酰肼成核剂，可有效促进高分子量聚（L-丙交酯）/聚（D-丙交酯）共混物中的立体络合物结晶
DOI：
10.1016/j.polymer.2020.122873
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发表时间：
2020-12-01
期刊：
影响因子：
4.6
通讯作者：
Chen, Jianyang
中科院分区：
文献类型：
--
作者：
Liu, Huili;Zhou, Wei;Chen, Jianyang
增强了聚L-丙交酯(PLLA)和聚D-丙交酯(PDLA)之间的CH3中心点O=C相互作用，有效地促进了高相对分子质量PLLA/PDLA共混物的立体配合物(SC)结晶，从而使SC型聚乳酸(PLA)具有优异的物理化学性能。本工作设计了一种新型芳基肼类成核剂N，N‘-水杨酸四(1，2，4，5-苯四甲酸)肼(BAS)，并将其应用于HMW-PLLA/PDLA共混物中，通过与聚乳酸形成大量氢键来增强共混物的链间相互作用。结果表明，BAS能同时提高外消旋共混物的结晶速度和SC结晶能力。无论是非等温晶化还是等温晶化，随着BAS含量的增加，Sc微晶的含量都有显著提高。更重要的是，在160℃等温结晶的三元共混物获得了具有相当高结晶度(X-c，X-Sc=53.0%)的完全Sc结晶，同时伴随着极快的结晶速度和高的成核密度。根据FTIR分析，BAS促进SC结晶的机理是由于BAS与聚乳酸之间存在丰富的氢键，从而大大增强了对映体的链间引力。我们相信，这项工作对开发新型高效的SC型成核剂和制备高性能的SC型聚乳酸材料具有重要的指导意义。
Enhancing the interchain CH3 center dot center dot center dot O=C interactions between poly (L-lactide) (PLLA) and poly (D-lactide) (PDLA) proves effective in promoting stereocomplex (SC) crystallization of high-molecular-weight (HMW) PLLA/PDLA blends and thus endowing SC-type polylactide (PLA) with super physicochemical properties. In this work, a novel aryl hydrazide-type nucleator N,N,N,N'-salicylic tetra(1,2,4,5-benzenetetracarboxylic acid) hydrazide (BAS) with plentiful hydrazide and hydroxyl groups was designed and applied into HMW PLLA/PDLA blends, aiming to enhance the interchain interactions by forming numerous hydrogen bonds with PLA chains. The results indicate that BAS can simultaneously improve the crystallization rate and SC crystallizaion ability of racemic blend. No matter in nonisothermal or isothermal crystallization, the fraction of SC crystallites all exhibits a substantial enhancement as the BAS content increases. More importantly, exclusive SC crystallization with a quite high crystallinity (X-c,X-SC = 53.0%) is achieved for the ternary blends isothermally crystallized at 160 degrees C, which is simultaneously accompanied by a extremely fast crystallization rate and high nucleation density. Based on FTIR analysis, the mechanism of BAS facilitated SC crystallization is interpreted to be the largely enhanced enantiomeric interchain attractions derived from the abundant hydrogen bonds between BAS and PLA. We believe this work could provide significant guidance to develop novel efficient SC-type nucleators and fabricate highperformance SC-type PLA materials.