Transport of Penetrant Molecules Through Natural Rubber Based Blends and IPNs
The transport of liquids, vapours and gases through polymer blends is of fundamental importance, and provides not only a valuable means for the characterization of blends, but also plays a vital role in a variety of barrier applications. The characteristic transport phenomena across polymer materials have been discussed. Natural rubber, its blends and interpenetrating networks (IPNs) have been discussed briefly so as to place it in context with the preceding chapter on transport studies. The transport properties of various natural rubber based blends and IPNs have been presented. Factors that affect the transport of liquids, vapours and gases through natural rubber blends and IPNs have been identified, and include the blend composition, miscibility, phase morphology, nature of penetrant molecules, the crosslink density, pressure, and temperature. The effects of these factors on the transport process have been highlighted. The equilibrium sorption of a vapour by natural rubber based blends is utilized in applications such as the separation of volatile organic compounds (VOCs) in vapour recovery from contaminated air. Similarly, the transport of gases through natural rubber based blends is an area of growing interest, with materials having unique transport properties being used in new, specialized applications. The effects of the presence of absorbed penetrant molecules on the properties of natural rubber based blends and IPNs are also discussed.