私密直播全婐app免费大渔直播,国产av成人无码免费视频,男女同房做爰全过程高潮,国产精品自产拍在线观看

當(dāng)前位置:群英聚首 > 論文著作 > 正文
Acceleration or Retardation to Crystallization if Liquid-Liquid Phase Separation Occurs: Studies on a Polyolefin Blend by SAXS/WAXD, DSC and TEM.
來源:許東華副研究員個(gè)人網(wǎng)站 發(fā)布日期:2020-04-05
作者:Yanhua Niu, Zhigang Wang*, Carlos Avila Orta, Donghua Xu, Howard Wang, Katsumi Shimizu, Benjamin
關(guān)鍵字:Crystallization, Liquideliquid phase separation, Polyolefin blend
論文來源:期刊
具體來源:Polymer 2007, 48, 6668-6680.
發(fā)表時(shí)間:2007年

Blends of statistical copolymers containing ethylene/hexene (PEH) and ethylene/butene (PEB) exhibited the behavior of upper critical solution temperature (UCST). The interplay between the early and intermediate stage liquideliquid phase separation (LLPS) and crystallization of the PEH/PEB 50/50 blend was studied by time-resolved simultaneous small-angle X-ray scattering (SAXS) and wide-angle X-ray diffraction (WAXD) techniques. Samples were treated by two different quench procedures: in single quench, the sample was directly quenched from 160 C to isothermal crystallization temperature of 114 C; while in double quench, the sample was firstly quenched to 130 C for 20 min annealing, where LLPS occurred, and then to 114 C. It was found that in the early stage of crystallization, the integrated values of Iq2 and crystallinity, Xc, in the double quench procedure were consistently higher than those in the single quench procedure, which could be attributed to accelerated nucleation induced by enhanced concentration fluctuations and interfacial tension. In the late stage of crystallization, some morphological parameters were found to crossover and then reverse, which could be explained by retardation of lamellar growth due to phase separation formed during the double quench procedure. This phenomenon was also confirmed by DSC measurements in blends of different compositions at varying isothermal crystallization temperatures. The crystal lamellar thickness determined by SAXS showed a good agreement with TEM observation. Results indicated that the early stage LLPS in the PEH/PEB blend prior to crystallization indeed dictated the resulting lamellar structures, including the average size of lamellar stack and the stack distribution. There seemed to be little variation of lamellar thickness and long period between the two quenching procedures (i.e., single quench versus double quench).


Copyright © 2005 Polymer.cn All rights reserved
中國聚合物網(wǎng) 版權(quán)所有
經(jīng)營性網(wǎng)站備案信息

京公網(wǎng)安備11010502032929號

工商備案公示信息

京ICP證050801號

京ICP備12003651號

主站蜘蛛池模板: 普宁市| 房产| 乐陵市| 仙游县| 阿巴嘎旗| 麻城市| 武强县| 渝北区| 浠水县| 聂荣县| 历史| 探索| 吐鲁番市| 内乡县| 聂拉木县| 九龙城区| 包头市| 宝清县| 霍邱县| 尉氏县| 岳阳县| 秦皇岛市| 高雄市| 温宿县| 溆浦县| 湘阴县| 大安市| 通化县| 拉萨市| 三亚市| 东安县| 灵石县| 托克逊县| 河南省| 江都市| 门头沟区| 林周县| 咸丰县| 温州市| 家居| 博兴县|