In this study a binary polymer blend was prepared and characterized by hand lay-up method. (Epoxy/polyvinyl chloride, EP/PVC) blends were prepared with different weight ratios of (0, 5, 10, 15 and 20) % of (PVC).
The influence of addition of (PVC) on the mechanical properties of epoxy resin (type Quickmast 105) was examined.Based on the homogeneity, miscibility and the higher impact strength, the ratio(80/20%) was selected as the best percentage and then this blend was reinforced with polypropylene, carbon fibers and hybrid of both types with fiber volume fraction (30%).
Differential Scanning Colarimeter test (DSC) was performed to determine the values of glass transition temperature (Tg) for the material under study, the results of this study show that the hybrid composite has the higher value of (Tg) compared with other materials. Thermo gravimetric analysis (TGA)was carried out to investigate the relation between the weight losses of sample with increase of temperature, it was found that the weight loss of epoxy resin decreases after blending with (PVC) and reinforcing the blend with fibers mentioned above.
Thermal conductivity test illustrated that studied materials have good thermal insulation as well as the hybrid composite has the minimum value of thermal conductivity coefficient. The microstructure and impact fracture surfaces of the blends and their composites were investigated by using scanning electron microscope (SEM). The experimental results show that the mixing ratio of 20% (PVC) has the highest impact strength compared with other ratios.
The percentage (80/20) % of (EP/PVC) reinforced with carbon fibers records the highest values for both impact strength (I.S) and Young's modulus (E) while the hybrid composite has higher Shore D hardness compared with other composites prepared from the same blend. After studying the mechanical properties (impact, hardness and bending) of immersed specimens in different types of water include (rain, distilled and tap water) for more than two months in sealed glass containers, it was observed these types of water have negative effect on the properties in different degrees depending on the absorption rate and diffusivity of water into the prepared materials, the values of water diffusion coefficients ranged within the order (10-12m2/s).