Efeito das condições de processamento e da adição de borracha trans-polioctenileno nas propriedades de blendas de borracha natural/estireno butadieno.

Abstract

Polymer blends are used in tyre industries because of their low cost and better properties. When the blend components are not miscible, chemical methods (using compatibilizing agents) or mechanical methods (increasing the mixture time of elastomers) of compatibilization are necessary to improve the compatibility of the components of the blend. In this work, Trans-Polyoctenylene Rubber (TOR) was used as a compatibilizing agent of the NR/SBR rubber blend. The Mooney viscosity, stress and elongation at break of different blends were evaluated, using a Factorial Design. The experimental results obtained showed that the Mooney viscosity is greatly affected by the addition of TOR whereas the dynamometric properties, the stress and elongation at break are more sensitive to the changes of processing time of polymers. Based on statistical results, regression equations to evaluate the properties studied as a function of TOR concentration and processing time were obtained and verified using blends which were not on the original design. The results were very satisfactory, either on the effects determination or on the regression equation determination. It was concluded that the Mooney viscosity is more sensitive to the alterations of TOR concentration than the changes in the processing time of the elastomers and the dynamometric properties are more affected by the processing time.