CHAPTER 27. Diffusion and Transport of Liquids, Vapours and Gases Through Natural Rubber Composites and Nanocomposites

Abstract

Diffusion and transport of liquids, vapours and gases through rubber is one of its important characteristics for users and industrial manufacturers when designing applications. Therefore, the diffusion and transport behaviour through many types of rubber have been studied by various modified techniques and standard methods in order to classify the barrier properties of natural rubber, natural rubber composites and nanocomposites. Generally, a natural rubber has low resistance to gas and moisture diffusion, resulting in degradation and shortened shelf life. Research projects have been conducted for a long time to discover strategies to overcome these drawbacks of natural rubber. Improving the barrier performance is an objective to prevent liquids, vapours and gases passing through the natural rubber easily. There are various processes and methods to achieve this goal. Preparation in the form of natural rubber composites has been used for this intention about 40 years. Due to the boom in nanotechnology, nanocomposites have been discussed for their advantages including ease of manufacturing, light weight and high barrier against diffusion and transport of moisture and gases. Conventional composites and nanocomposites are the same in combination of two or more materials; the rubber as a main material for continuous phase called matrix and other materials called dispersed phase with difference in nano size of nanocomposites. These methods are interesting to improve various properties in many applications. However, the properties of natural rubber composites and nanocomposites still depend on concentration, size, shape, distribution and orientation of the dispersed phase. In addition, temperature is one of the factors that affects various diffusion and transport profiles of their characteristics.