Voids resin water concentration

For the T300/Narmco 5208 system, the water concentrations within the bulk resin and at the void surface were obtained from measured solubility, weight fraction, and density data. The water concentration in the bulk resin is dependent only on the initial relative humidity under which the resin was equilibrated and is given by ... 

A model and attendant computer code have been constructed to describe time-dependent void growth and stability for any processing cure cycle. Although the analysis is approximate, it does account for the moving void-resin boundary layer and its effect on the concentration profile and diffusion of water in the resin. It was found that for the duration of the cure cycle it makes little difference whether the initial small voids contain pure water or mixtures of air and water. 

Qa, concentration of water or solvent in void at void-resin interface, gm/cm3... 

For some nonionic, nonpolar polymers, such as polyethylene glycols, normal chromatograms can be obtained by using distilled water. Some more polar nonionic polymers exhibit abnormal peak shapes or minor peaks near the void volume when eluted with distilled water due to ionic interactions between the sample and the charged groups on the resin surface. To eliminate ionic interactions, a neutral salt, such as sodium nitrate or sodium sulfate, is added to the aqueous eluent. Generally, a salt concentration of 0.1-0.5 M is sufficient to overcome undesired ionic interactions. 

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