文献类型：期刊文献

英文题名：The melt grafting preparation and rheological characterization of long chain branching polypropylene

作者：Li, Shuzhao[1];Xiao, Miaomiao[3];Wei, Dafu[2];Xiao, Huining[3];Hu, Fuzeng[1];Zheng, Anna[1]

机构：[1]E China Univ Sci & Technol, Sch Mat Sci & Engn, Shanghai 200237, Peoples R China;[2]E China Univ Sci & Technol, Key Lab Ultrafine Mat, Minist Educ, Shanghai 200237, Peoples R China;[3]Univ New Brunswick, Dept Chem Engn, Fredericton, NB E3B 6C1, Canada

年份：2009

卷号：50

期号：25

起止页码：6121

外文期刊名：POLYMER

收录：;EI(收录号：20094712485087);WOS:【SCI-EXPANDED(收录号:WOS:000272284100031)】；

语种：英文

外文关键词：Polypropylene (PP); Rheology; Melt grafting

摘要：To study the theological properties of long chain branching (LCB) polypropylene (PP), long chain branches (LCB) were grafted onto the linear PP by melt grafting reaction in the presence of a novel chain extender, poly(hexamethylendiamine-guanidine hydrochloride) (PHGH). The branching reactions between the functionalized PP and PHGH were confirmed by transient torque curves and FTIR. By differential scanning calorimetry (DSC) and polarized microscope measurements, the presence of long chain branching structures was further confirmed. Also, the viscoelastic properties of the LCB PP and linear PP under shear flow were investigated for distinguishing LCB PP from linear PP. It was found that the elastic response of LCB PP at low frequencies was significantly enhanced in comparison with that of the linear PP, implying a presence of a long relaxation time mode that was not revealed in linear PP. Moreover, the branching levels of LCB PP were quantified using a detailed method, which was in correspondence with the molar amount of PHGH grafted on PP. (C) 2009 Elsevier Ltd. All rights reserved.