THERMAL-CONDUCTIVITY OF POLYETHYLENE POLYSTYRENE BLENDS CONTAINING SEBS BLOCK COPOLYMER

We measured the thermal conductivity of a polyethylene/polystyrene blend containing SEBS block copolymer, which has two components of polystyrene block and hydrogenated polybutadiene block, and discussed the effect of phase inversion on the thermal conductivity by observing the morphorogy of the blend. Further, we examined the applicability of the thermal conduction model for composites, which was proposed in our previous reports, to this blend system. By plotting the logarithm of the thermal conductivities of the blends vs. the weight content of polyethylene, it was found that the experimental data lie approximately on a straight line with an increase in polyethylene until the range of dual-phase continuity (phase inversion), and then the data move on another straight line beyond the range of dual-phase continuity. Thus, our model to explain the thermal conductivity of the polymer blend was proved. Further, both coefficients A and B in our model took linear relations with the weight content of the block copolymer, and the model was, thus, more strongly confirmed to be applicable to thermal conductivity of polymer blends.