Premium
Crystallinity and mechanical properties of PP‐homopolymers as influenced by molecular structure and nucleation
Author(s) -
Gahleitner Markus,
Wolfschwenger Johannes,
Bachner Claudia,
Bernreitner Klaus,
Neißl Wolfgang
Publication year - 1996
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/(sici)1097-4628(19960725)61:4<649::aid-app8>3.0.co;2-l
Subject(s) - nucleation , tacticity , crystallinity , molar mass , materials science , polymerization , polymer chemistry , polymer science , chemical engineering , composite material , polymer , chemical physics , thermodynamics , chemistry , physics , engineering
The evolution of crystallinity and mechanical properties of two different series of PP‐homopolymers (RE grades coming directly from the polymerization reactor and CR grades priorly subjected to a defined degradation process) as influenced by the molar mass and heterogeneous nucleation was investigated, including one highly isotactic material to check the tacticity influence. In principle, the effects seem explainable by differences in the number of nuclei and the spherulithic growth speed, which were determined separately. The nucleation effects are similar for all materials, but strongly dependent of the molar mass of the materials. Apart from the bulk material properties, also the development of shearinduced structures is strongly influenced by molar mass and nucleation, contributing additionally to mechanics. © 1996 John Wiley & Sons, Inc.