A Brief Study about High Performance Oil Resistant Rubber

Abstract

The present work is aiming to elaborate high performance oil resistant rubber products based on NBR, PVC and CR blends to be utilized in automobiles industry. The blend vulcanizates are evaluated by rheological, physical and mechanical characteristics.

The characteristics of the designed blends either binary blends (NBR/PVC or PVC/CR) or ternary blends (NBR/ PVC/CR) were investigated by rheological properties, mechanical analysis and swelling in oil and toluene. Since many different replacement components may come into touch with oils and greases, oil-resistant polymeric materials are crucial for the automotive sector. The chemical makeup of rubber, specifically its electro-negativity and crystallinity, is crucial in the creation of goods that are resistant to oil. It was found that the incorporation of PVC in the blend compositions leads to the decrease in degree of swelling, the penetration rate and the average diffusion coefficient. On the other hand the ultimate tensile strength (UTS), the hardness and strain energy were increased. This was attributed to the plastic nature of PVC, beside its additional behavior as filler. The crosslinking density in the blend vulcanizates under investigations was determined by Flory-Rehner and Mooney-Rivlin [Stress/Strain] equations. The diffusion in rubber is important, because it is always used in contact with foreign molecules, which may be gases, liquids, or solids. The study of diffusion of oils or organic solvents in rubber products is very serious from scientific and economic points of view. The oil resistant rubbers are important in automotive industry. Oil resistance is the reciprocal of the degree of swelling in oil and is governed by the competition between the driving force towards dissolution of the rubber in the low-molecularweight oils and the intermolecular forces of the polymer matrix. The additional physical crosslinks (such as entanglements, etc.), in addition to the chemical crosslinks established by swelling in toluene, can be blamed for the higher values of crosslinking density reported by Mooney-Rivlin. This study demonstrated the good performance oil resistance of NBR/PVC blends, which can be suggested to the automotive industry.