Randomized solid state bulk functionalization of aramid fiber pulp and its application in elastomer compositions

Abstract

AbstractN‐oxydiethylene‐2‐benzothiazole sulphenamide (NOBS) dispersed in an inert (saturated main chain) rubber matrix (ethylene‐co‐propylene‐diene monomer [EPDM], as carrier to be dispersed later in a predetermined lower quantities) containing definite amount of pre‐dried aramid fiber pulp (AP) was subjected to internal thermal influence as heated through dielectric‐dielectric interaction in a laboratory microwave oven. The reactions of NOBS with aramid fiber pulp (on the surface and in the bulk) were characterized using XPS, TGA, FTIR, SEM, and mechanical properties. The objective was to confirm the efficacy of dielectric heating in situ and to promote functionality for bonding with rubber. The functionalization was considered to be provided by NOBS. One such chemical modification was found to be the generation of free ends in the AP and it was characterized by XPS. At the same time, there was no thermal degradation as confirmed from TGA studies. The rubber‐AP masterbatch (as previously prepared was dispersed) in different proportions in Butadiene‐co‐acrylonitrile rubber (NBR) and various characterizations related to plain rubber compound and in the cross linked states including fluid barrier properties and spring characteristics were found to record a significant improvement. The SEM micrographs showed that the fiber‐rubber cohesion and the rubber‐AP interaction are enhanced due to the proposed dielectric heating induced functionalization of AP.