Avaliação das propriedades térmicas, morfológicas e de dureza em blenda PVC/NBR aplicado em juntas industriais

Abstract

PVC/NBR blends currently have great industrial potential for various applications. In this context, this work aims to evaluate the miscibility of the PVC/NBR blend through thermal, morphological properties and hardness for application in industrial joints. For this purpose, developed four formulations called PVC40C30NBR, PVC10C30NBR, PVC40C10NBR and PVC10C10NBR, whose purpose was to vary the quantities of calcium carbonate and NBR rubber. The results showed that the blend of PVC/NBR is miscible and, due to this characteristic, the transition temperature vitrea is smaller when compared to that of PVC reported in the literature. Furthermore, it is noted that the presence of calcium carbonate did not significantly influence on that property. When evaluated, scanning electron microscopy is it is possible to observe the miscibility of the PVC/NBR system and some pullout points on the fracture surface, indicating that there was not good anchoring of the calcium carbonate in the polymeric matrix. The hardness results indicate that the presence of NBR promotes the reduction of this property in the Shore D scale, corroborating with the miscibility seen in the microscopy. Events are also observed endothermic in the DSC thermal analysis indicating pyrolysis gases, being those of hydrochloric acid and acrylonitrile, C=C trans bonds present in NBR or C=O of the carbonyl additive. For the TGA it was possible to visualize the events of degradation of compounds present in PVC and NBR, as expected.