Effects of Fillers on Mechanical, Physical, Swelling and Thermal properties of Hydrogenated Acrylonitrile Butadiene Rubber (HNBR)

Abstract

HNBR in pure form has low mechanical and physical properties and therefore not suitable for some special applications. Moreover under some typical environmental condition in industries and aerospace high thermal stability of rubber components are required. Furthermore HNBR has resistance to oil, fuels and other solvent, therefore it can be used for different o-rings and gasket, but under special requirements, pure HNBR cannot serve the purpose due to their high swelling ratio. Compression strength is an important parameter, because most of the products are subjected to compressive loads like tires of automobiles, footwear, oil seals, engine mounting and rubber bearings for bridges and brake linings. In order to overcome these problems and enhance physical, mechanical, thermal and swelling properties for using of rubber components for proper industrial applications, some ingredients are added to the pure HNBR called additives. This process of addition of ingredients/additives is called rubber compounding/mixing. In ingredients mainly filler, cross linker, accelerator and activator are used. In filler carbon black, silica and clay is use for reinforcement, cross linker like sulphur is used for cross linking whereas accelerator and activator are used to shorten the curing time, because curing is a very tedious process and required a lot of time. In this experimental work rubber compounding is carried out by using two roll-mill machine and eleven recipes have been prepared having different ratio of carbon black and silica loading keeping the remaining ingredients constant. Curing has been carried out by using compression molding machine, testing for physical, mechanical, thermal and swelling properties have been carried out accordingly and finally test results are shown in tabulated form as well as graphical form for analysis.