Transport of penetrant molecules

The barrier performance [4] of a polymer can be defined as its resistance to the transport of penetrant molecules, i.e., as the inverse of its permeability. A lower value of P therefore indicates better performance as a barrier material. 

Transport of Penetrant Molecules Through Copolymers of Vinylidene Chloride and... 

The study of the transport of penetrant molecules through polymers [1,2] is important in many areas of technology. There are two types of industrially important polymeric systems for which such transport phenomena are crucial ... 

Figure 1. Schematic illustration of how the results of three different types of calculations, each one providing a perspective at a different scale, can be combined synergistically, to construct a unified physical model for the transport of penetrant molecules in plastics.

A study is in progress on the transport of penetrant molecules in barrier plastics, utilizing a synergistic combination of techniques. 

Transport of Penetrant Molecules Through Natural Rubber Based Blends and IPNs... 

Reports in the literature on the transport of penetrant molecules through NR based blends and IPN s are few when compared to the existing literature on most common/commercial polymers/blends. The sorption and diffusion of aromatic penetrants into different NR blends such as NR/BIIR, NR/CIIR, NR/neoprene, NR/EPDM, NR/polybutadiene, and NR/SBR were studied by Siddaramaiah et al. The diffusion coefficient (D) of the penetrants was found to range from 6.8 to 84.3 x 10 cm /s at a temperature range of 25-60 °C. Results indicated that the transport data were affected by the nature of the interacting solvent molecule rather their sizes, and also by the structural variations of the elastomers blended with NR. The activation parameters for the diffusion of the penetrants ranged from 4.16 to 30.48 kJ/mol. 

Despite the few reported research being carried out on the transport of penetrant molecules through NR based IPNs, data obtained from the transport studies can be used to advantage in determining parameters of importance as they relate to rubber based networks. The following parameters can be determined (i) The molecular weight between crosslinks (Me) can be calculated as ... 

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