Full-Text Search:
Home|Journal Papers|About CNKI|User Service|FAQ|Contact Us|中文
《高分子科学(英文版)》 2016-09
Add to Favorite Get Latest Update

Crosslinking Kinetics of Polyethylene with Small Amount of Peroxide and Its Influence on the Subsequent Crystallization Behaviors

Yan-hua Niu;Wen-bin Liang;Yin-ling Zhang;Xue-lian Chen;Shih-yaw Lai;Guang-xian Li;Du-jin Wang;College of Polymer Science and Engineering, State Key Laboratory of Polymer Materials Engineering of China,Sichuan University;Performance Material Center, National Institute of Clean-and-low-carbon Energy (NICE);CAS Key Laboratory of Engineering Plastics, Beijing National Laboratory for Molecular Sciences, Institute of Chemistry,Chinese Academy of Sciences;  
Crosslinking reactions of high density polyethylene with low peroxide concentrations ranging from 0.1 wt% to 1.0 wt% at temperatures of 170, 180 and 190 ° C were monitored by rheological measurements. A critical gel forms at the peroxide concentration of 0.2 wt%, where the transition from long chain branching generation to crosslinking network formation could occur. Rheokinetics of crosslinking can be fitted well by Ding-Leonov's model. The curing rate k_2 at the earlier stage exhibits about 3 times acceleration per 10 °C with increasing temperature, while the equilibrium modulus G′ at the fully cured stage is almost independent of temperature. Influences of crosslinking on the subsequent crystallization behaviors were detected by DSC measurements. Above the critical gel concentration, crystallization is largely retarded as evidenced by the lower crystallization temperature Tc and crystallinity X_c due to the network formation. The secondary crystallization valley located at the temperature near 80 °C can be observed above the critical concentration, which becomes more evident with the increasing peroxide concentration and curing temperature. This phenomenon provides another evidence of crystallization retardation by the crosslinking network.
【Fund】: financially supported by the Technical Innovation Project of National Institute of Clean and Low-Carbon Energy(No.15H0543);; the Open Project of State Key Laboratory of Polymer Materials Engineering of China(Sichuan University)(No.sklpme2015-4-11)
【CateGory Index】: TQ325.12
Download(CAJ format) Download(PDF format)
CAJViewer7.0 supports all the CNKI file formats; AdobeReader only supports the PDF format.
©2006 Tsinghua Tongfang Knowledge Network Technology Co., Ltd.(Beijing)(TTKN) All rights reserved