Specific Heat and Thermal Expansion Coefficient of Hybrid Epoxy Composites

Thermal behavior of hybrid epoxy composites reinforced with different types of plain weave fabrics and ply orientation at various angles was investigated in this research. It was analyzed their thermal linear expansion coefficient and specific heat measured with Thermomechanical Analyzer (TMA) and Differential Scanning Calorimeter (DSC) respectively. Also, in this paper was studied the influence of carbon black - aramid powder and carbon black - barium ferrite mixtures added into epoxy matrix between certain plies of the hybrid composites. The experimental results showed that the addition of filler mixtures led to a significant decreasing of thermal expansion coefficient and specific heat of the hybrid epoxy composite with carbon outer plies. It was recorded a good structural stability in case of hybrid carbon-glass composite in the temperature range of 40-60�C.

An Experimental Investigation of Thermal Properties of Fabric Reinforced Epoxy Composites

Specific heat and thermal linear expansion coefficient of epoxy composites reinforced with carbon, aramid, glass and hybrid fabrics with unfilled and filled stratified matrices were studied. The thermal measurements of specific heat were performed with Differential Scanning Calorimeter (DSC instrument) and those of thermal coefficient of linear expansion were realized with Thermomechanical Analyzer (TMA instrument). It was analyzed the influence of fiber orientation at various angles (�15�, �30� and �45�) and the effects of two types of filler mixtures added into polymeric matrix on the thermal behavior of composite materials. It was found that in case of epoxy matrix the added filler mixtures reduced its thermal coefficient of linear expansion and had an insignificant influence on specific heat. In case of epoxy composites reinforced with fabrics, the fiber orientation and fillers addition showed different effects on the investigated thermal parameters in dependence of the used reinforcement types.