The Effect of Crossunking on Toughness of Composite Ldpe/Silica

The effect of crosslinking on the toughness of LDPE filled with two different grades of silica was investigated. An elastic plastic fracture mechanism based on the J integral has been used to evaluate the results of notch impact resistance. Crosslinking of the matrix in PE/silica composites leads to improved toughness when compared to uncrosslinked composites. The increase of toughness results mainly from an increase in the amount of plastic deformation and, consequently, higher ultimate deformation at fracture. A positive effect of crosslinking on the development of plastic deformation was also demonstrated by SEM, showing that the fracture is entirely cohesive.