Diblock Co-Polymer Reinforced Interfaces between Amorphous Polystyrene and Semicrystalline Polyethylene

The interface between Polystyrene (PS) and polyethylene (PE) normally has low fracture energy (Gc) on the order of 1 J/m2. The strength of the interface can be improved by reinforcing them with PS-PE diblock copolymer. For this experiment, the molecular weight of PS was held constant, while the molecular weight of the PE block was varied. The areal chain density of the diblock copolymer (å) was held constant for all tests. We measured Gc as a function of temperature using the asymmetric double cantilever beam test (ADCB). By observing the dependence of Gc on temperature, we can discuss whether or not the pullout of the PE block from bulk PE is a thermally activated process. Understanding PE fracture properties will help us improve the durability of polymers blends.