Effect of Changing Environments on Microstructure of HDPE Polymer

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