TITLE:
Effect of Changing Environments on Microstructure of HDPE Polymer
AUTHORS:
S. Bal, D. Mahesh, T.K. Sen, B.C. Ray
KEYWORDS:
HDPE, Thermal cycling, Humidity cycling, Tensile, Impact, Cross-linking, Degradation.
JOURNAL NAME:
Journal of Minerals and Materials Characterization and Engineering,
Vol.6 No.1,
June
12,
2007
ABSTRACT: The analysis of environmental effects on microstructure of HDPE polymers were
done according to their mechanical behavior obtained from tensile, impact and
microhardness testing and thermograms obtained from DSC. The samples were
conditioned under three different kinds of humidity and temperature environment. With
increase in conditioning time, the variations of tensile strength, impact, microhardness
were observed to be nonlinear in nature. The high values are possibly due to
polymerization such as cross-linking. The low values may be attributed by
depolymerization mechanism such as chain scission and bond breakage. The variation of
data is due to more physical damage of the polymer because of unequal expansion of the
surface. The refrigeration also affects the crystalline regions by changing free volume.
Again rearrangement of end groups in the lamella through partial melting and
recrystallization are observed due to thermal conditioning and thermal shock.