Effect of green modification of nanoclay on the adhesion behavior of EPDM rubber to polyester fabric

Abstract

Rubber-coated fabrics have received much attention because of their excellent processability and unique mechanical properties. In this research, two approaches were used to prepare organoclay/ethylene propylene diene terpolymer (OC/EPDM) nanocomposites. One of them was based upon a nonpolar EPDM in which the EPDM was grafted with maleic anhydride (EPg) with OC namely (OC/EPg/EPDM); while the other was based on a green modified organoclay in which stearic acid was used to form an expanded organoclay (EOC) namely (EPDM/EOC). The EPDM compounds were loaded with 20 wt% of a long oil alkyd resin based on soyabean oil (LAR). The bonding system applied in the mixes consisted of hexamethylenetetramine-resorcinol-hydrated silica (HRH). The different mixes were loaded with different concentrations of OC and EOC. The rubber nanocomposites were immersed in an equal weight of toluene to prepare a rubber dough. This dough was spread over a polyester fabric; cured to form the final proofed product. The peel strength technique was used to assess the adhesion strength between the EPDM rubber and the polyester fabric. The reaction mechanism of EOC with the EPDM/polyester fabric in the presence of a bio-alkyd resin was studied. Moreover, the rubber proofed fabric was subjected to ultraviolet (UV) irradiation at different doses. The net product of proofed fabric was also subjected to various tests such as air and water permeability, flammability and antimicrobial activity. In all cases, the use of the EOC/EPDM or the OC/EPg/EPDM systems enhanced the physico-mechanical and physico-chemical properties of the rubber-proofed fabrics with the exception of thermal stability as determined from themogravimetric analysis which decreased, especially the degradation onset temperature (T10%). These materials provide a promising approach for use in advanced rubber technology applications.