Effects of low-dose electron beam irradiation on linear low density polyethylene/ternary copolymer polypropylene polyolefin structure and properties

Abstract

This study investigated the impact of low-dose electron beam irradiation on the structure-property correlation of linear low-density polyethylene (LLDPE), ternary copolymer polypropylene (co-PP), and their blends. Effects of the absorbed dose on the rheological properties, strength, crystallization behavior, crystal structure, and mechanical properties of LLDPE/co-PP blended polyolefins with various blending ratios were examined. The melt index test results indicate that, for LLDPE: co-PP ratios of 3∶1 and 1∶1, the melt index of each prepared polyolefin decreases and its crosslinking degree increases as the absorbed dose increases. However, for a LLDPE: co-PP ratio of 1∶3, the crosslinking degree of the polyolefin decreased with increasing absorbed dose. The crystal structure and crystallization behavior of the polyolefins were minimally affected by their absorbed doses, however, varying the ratios of blended LLDPE and co-PP affected the crystallization of both LLDPE and co-PP. For a blend with 1: 1 ratio, an absorbed dose greater than 2 kGy resulted in a sample elongation at break exceeding 890% and a fracture strength of 25.4 MPa those of both LLDPE and co-PP. Additionally, the stress-strain curves of the prepared polyolefins indicated that the absorbed dose enhanced the compatibility between LLDPE and co-PP. Thus, low-dose irradiation of LLDPE/co-PP polyolefins would offer a new avenue of research on polyolefin product development.

Keywords

• copolymer polypropylene
• linear low density polyethylene
• radiation modification
• low absorbed dose