Thermal and mechanical properties of extruded LLDPE/wax blends

The thermal and mechanical properties of linear low-density polyethylene (L LDPE)/wax blends, prepared in an extruder, were investigated, using differe ntial scanning calorimetry (DSC) and tensile testing. DSC measurements indi cated that blends consisting of 10 and 20% of wax are probably miscible in the crystalline phase. For 30% and more wax, phase separation of the two co mponents were observed. The DSC curves of both pure LLDPE and blends show, beside the main exothermic peak, another small peak at about 70 degreesC. S ince this peak was observed for both pure LLDPE and the blends, it is proba ble that its origin is partly in the LLDPE structure, but it is also influe nced by wax crystallization. An increase in Young's modulus with an increas e in wax content was observed. An increase in wax content causes a decrease in elongation at yield. A small increase in yield stress was observed for blends consisting of 10 and 20% of wax. For blends consisting of 30% and mo re wax, no yield point, but brittle rupture, was observed. (C) 2001 Elsevie r Science Ltd. All rights reserved.