The high performance and unique utilization properties applied by designers according to improvement of thermal and mechanical products were reinforced by particulate materials. The present study deals with the preparation of a composite system (EP/PVC). afterward the estimation of thermo-chemical behaviour of epoxy composite (EP/PVC) reinforced by addition of micro-fillers particulate of waste scrap tires (WST). Three different sets of epoxy-PVC composites are fabricated with addition of 0, 0.25, and 0.4 wt% of WST particulates. These composites have been prepared and both chemical reactivity absorbance and thermal conductivities are achieved. From results it appeared that a decreasing in thermal conductivity values about 55 % for 0.25wt % for a micro-WST of epoxy composite system, of 0.4wt. %recorded decreasing of thermal conductivity at88 %when compared to epoxy composite system (EP/PVC). The results show that the (WST) micro-fillers particles show an insulation polar behaviour at 0.4 wt. % at which a random behaviour in thermal conductivity is recorded .In addition to an experimental examination of chemical activity absorbance for both composite system before and after additive of micro-filler particulate of waste scrap tires (WST) in different soaking medium (normal and acidic solutions) and different residence times (0-120 hrs) respectively. The results proved that an improvement chemical activity occurred for optimum sample no. 3 of (2.5/ .4 + .4 (EP/PVC + WST) that have minimum loss in weight as (0.001) under both soaking medium (100% H2O, 10% H2SO4) rather than base composite system (EP/PVC) and other improved one of .25 wt. % from WST of (0.01 – 0.05) respectively.