Ethylene–Propylene–Diene Rubber-Based Nanoblends: Preparation, Characterization and Applications

Abstract

In the process of macromolecule cross-linking, the choice of type and quantity of the both, components and experimental condition, are important to obtain the new cross-linked materials with better mechanical and chemical characteristics. The mechanism of cross-linking depends on of the rubber type and structure. That is an intermolecular cross-linking resulting in the elastomer network formation. The effect of different type of the fillers (carbon black-(CB) and silica) on the cure kinetics, mechanical properties, morphology and thermal stability of ethylene–propylene–diene rubber (EPDM), acrylonitrile–butadiene rubber (NBR) and EPDM/NBR rubber blends were investigated. The determination of cure characteristics was estimated by Monsanto Oscillating Disc Rheometer R-100. Mechanical properties such as tensile strength, elongation at break, modulus at 200 and 300 % elongation, hardness, have been measured at room temperature on an electric tensile testing machine (Zwick 1425) according to ASTM D 412. Morphology of the cross-linked system was carried out by scanning electron microscope (SEM). The non-isothermal degradation processes of EPDM, NBR, and EPDM/NBR rubber blends reinforced with carbon black and silica fillers (prepared in different ratios (as to parts per hundred of rubber (phr)) were investigated with thermogravimetric analysis (TGA) and derivative thermogravimetry (DTG), using the different calculation procedures. Model-free and model-fitting methods were combined to obtain the accurate kinetic triplets (A, Ea, and f(α)) for the degradation processes. For all investigated systems, an artificial compensation effect (art-CE) was found. It was found that the EPDM and the NBR rubber degradations represent the complex processes, where there are conversion regions with a constant value of the apparent activation energy (Ea).