Premium
Morphology and Stress Whitening of Heterophasic Poly(propylene) Copolymer/High Density Polyethylene Blends
Author(s) -
Jang Hee Jung,
Kim SoonDeok,
Choi Wonsook,
Chun Yong Sung
Publication year - 2012
Publication title -
macromolecular symposia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.257
H-Index - 76
eISSN - 1521-3900
pISSN - 1022-1360
DOI - 10.1002/masy.201100021
Subject(s) - high density polyethylene , materials science , polyethylene , composite material , scanning electron microscope , copolymer , morphology (biology) , polymer , biology , genetics
Abstract Summary: Effect of high density polyethylene (HDPE) addition on the morphology of heterophasic poly(propylene) copolymer (HPC) was investigated by transmission electron microscopy (TEM) and scanning electron microscopy (SEM). Stress whitening developed upon dart impact was evaluated using Gardner‐type impact tester. In the TEM study of HPC/HDPE blends, a core‐shell morphology was observed of HDPE encapsulated by ethylene‐propylene rubber (EPR). At low HDPE weight fractions (95/5 and 90/10 HPC/HDPE), the size of dispersed phase increased compared to pure HPC. However, further increase in HDPE leads to a decrease in domain size. The impact strength reached a maximum at 90/10 HPC/HDPE blend, and then decreased with further increase in HDPE content. The stress whitening of HPC was decreased with addition of HDPE. This decrease is attributed to the difference in the shrinkage between HPC and HPC/HDPE blends. The pressure‐volume‐temperature relationship supports that an additional volume contraction of HDPE can reduce the stress whitening of HPC.