Abstract:

The modification of polyethylene （PE） and maleic anhydride （MAH）⁃grafted PE were investigated using the peroxide crosslinking agent 1，3⁃bis（tert⁃butylperoxyisopropyl）benzene （BIPB）. The crosslinked materials were systematically characterized through FTIR spectroscopy， surface oxygen content analysis， mechanical testing， and thermal analysis. Results revealed distinct oxygen sources in crosslinkable versus crosslinked materials： while MAH and BIPB contributed oxygen in uncrosslinked powders， only MAH⁃derived oxygen remained after crosslinking due to BIPB decomposition. Increasing crosslinking degree led to MAH enrichment at material interfaces and the formation of distinctive interfacial morphology， accompanied by a decrease in crystallization onset temperature from 116.99 to 113.17 °C. As BIPB content increased from 0.1 to 0.5 phr， significant property changes were observed as follows： crystallinity decreased from 49.4 % to 42.2 %， tensile strength declined from 13.2 MPa to 11.1 MPa， and bonding strength reduced from 4.01 MPa to 3.53 MPa. These findings provide crucial insights into the structure⁃property relationships of peroxide⁃crosslinked PE systems， particularly regarding the competing effects of crosslinking density and crystallinity on mechanical performance.

Key words: peroxide crosslinking, polyethylene, adhesion modification, maleic anhydride grafted polyethylene