Effect of styrene-butadiene-styrene block copolymer on dynamic-mechanical properties of high-impact polystyrene

For the selection of the polymer materials and polymer blends for various fields of applications, dynamic-mechanical properties, the primary viscoelastic functions and the stability of materials on different loads are very important. Since polymer materials are viscoelastic, their mechanical properties are dependent on temperature and time. The dynamic-mechanical properties of high-impact polystyrene, (PS-HI) and blends of PS-HI and styrene-butadiene-styrene block copolymer, (SBS) were investigated. Under the conditions of dynamic-mechanical load, the investigated systems will have different behavior due to the various content of the hard phase, polystyrene and soft phase, polybutadiene. The investigations were done by DMA analysis. The primary viscoelastic functions were determined. The influence of the constant stress on the strain and moduls at various temperatures was examined. The effects of the time on modulus changes was obtained by generating the master curves. The viscoelastic functions and the stability on the constant load, the changes of the modulus with time and temperature depend on the amount of polystyrene in the examined copolymers and blends. This investigation presents the possibility of predicting a useful lifetime of materials.