Estudo da influência de resinas de tack em formulações elastoméricas e metodologias de avaliação aplicadas

Abstract

The present work aimed to evaluate the influence of different types of tack resins in elastomeric formulations, as well as to develop a simple, robust and reproducible test methodology to evaluate the tack of these elastomeric formulations using synthetic rubber (SBR). The formulations were developed using eight different types of tack resins, derived from different sources, such as: phenol-formaldehyde (SP - 1068, CRJ - 418, Koresin and SRF - 1501), hydrocarbons (Unilene A - 90 and Plastack RB 809), coumarone and natural (pitch). Several methodologies have already been developed for tack evaluation, however, until today, the ideal instrument hasn't been obtained, thus, a simple and easy-to-reproduce test methodology was developed. The characterization of the formulations was carried out through rheometric properties, mooney viscosity, crosslink density by swelling in solvent, hardness, abrasion wear, tensile and tear strength. The results obtained indicate that the phenolic and coumarone resins present better results, with the except of the resol-type resin, which showed the worst results. On the other hand, hydrocarbon resins and resins derived from rosin showed similar values. During the tests carried out, interference of some functional groups present in the chemical structure of the resins, difficulty in interacting with the matrix, lower indices in relation to cross-link density and vulcanization content were observed. The results obtained indicate the possibility of using some types of tack resins, in order to improve adhesion in the elastomeric compounds studied. [resumo fornecido pelo autor]