Pressure induced crystallization and in situ simultaneous SAXS/WAXS investigations on structure transitions,CrystEngComm

当前位置： X-MOL 学术 › CrystEngComm › 论文详情

Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)

Pressure induced crystallization and in situ simultaneous SAXS/WAXS investigations on structure transitions
CrystEngComm ( IF 2.6 ) Pub Date : 2020-06-10 , DOI: 10.1039/d0ce00548g
Shaoyong Huang _{1,

2,

3,

4,

5} , Hongfei Li _{1,

2,

3,

4,

5} , Shichun Jiang _{5,

6,

7,

8}

Affiliation

Pressure effect is of great importance in injection and compression of poly(L-lactide) (PLLA). However, pressure induced crystallization (PIC) and structural change of PLLA have not been thoroughly studied. In this study, we investigated PIC and structure transitions of PLLA using in situ WAXS and SAXS. A mixture of α′ and α crystals were observed at temperatures above 170 °C at high pressures. A frustrated structure was induced at P_c ≥ 100 MPa owing to sliding of chains and crystal blocks upon volume shrinkage. A mesomorphic phase was observed at P_c ≥ 100 MPa or at 190 °C ≥ T_c ≥ 165 °C by SAXS and WAXS. Upon heating the samples prepared at high P_c, doubling lamellar thickening occurred via mutual chain rearrangement between the adjacent lamellae. Based on the results, a phase diagram was revealed for the crystal structures formed and under different crystallization conditions.

中文翻译：

压力诱导结晶和原位同时SAXS / WAXS研究结构转变

压力效应在聚（L-丙交酯）（PLLA）的注射和压缩中非常重要。但是，压力诱导结晶（PIC）和PLLA的结构变化尚未得到彻底研究。在这项研究中，我们使用原位WAXS和SAXS研究了PLLA的PIC和结构转变。在高于170°C的高温高压下观察到α'和α晶体的混合物。沮丧的结构在被诱导P _Ç ≥100MPa的由于在体积收缩链和晶体块的滑动。在观察到介晶相，P _{c ^} ≥100MPa以上，在190℃≥ Ť _Ç ≥165℃通过SAXS和WAXS。加热后以高P制备的样品_c，通过相邻薄片之间的相互链重排，使薄片的厚度增加了一倍。根据结果，揭示了在不同结晶条件下形成的晶体结构的相图。

更新日期：2020-07-20

点击分享查看原文

点击收藏

阅读更多本刊最新论文本刊介绍/投稿指南11