Sorption equilibria and diffusion of toluene, methanol, and cyclohexane in/through elastomers

Abstract

Molecular transport of toluene, methanol, and cyclohexane and their mixtures in Chemraz 505 elastomer has been investigated using gravimetric techniques for short and long time exposure in these solvents. The sorption-desorption results have been used to calculate the diffusion coefficients by solving Fick's equation under appropriate boundary conditions. The dependence of sorption, desorption, diffusion, and permeation on temperature and composition changes was also studied. The results are discussed in terms of possible interactions between Chemraz 505 polymer and the solvent molecules. V C 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43449.

The compatibility of high‐density polyethylene piping and elastomers with the future fuel methanol

“…The primary elastomer materials used in the NG network are nitrile and fluoropolymer varieties, along with styrene butadiene rubbers used in coatings 15 . Considering the highly soluble nature of methanol, interactions with the many polymeric components of the pipeline network are possible, resulting in changes in mechanical properties as well as significant permeance through the material and therefore loss of the fuel 16 . Hence, there is need to establish the compatibility of plastic pipelines and their associated elastomers with methanol, to determine if methanol can be safely transported through the NG pipeline network.…”

Safe and cost-effective rapid-prototyping of multilayer PMMA microfluidic devices

“…However, as the Taguchi method aims to reduce the amount of total experiments required by adding together the main effects of independent variables, it was not applicable to this study and led to misleading results in optimisation terms. Indeed, solvent type, temperature and bonding time cannot be considered as independent variables and their effects are not separable, as the physics ruling the bonding process (solubilisation of the polymer chains, diffusion of solvent within the polymer matrix) follows kinetics in which the solvent molecules/ polymer interactions are strictly connected to temperature (Santos et al 2016;Bird et al 2002;Green and Perry 2008). Also, bonding strength is not a monotonic function of bonding pressure (as we demonstrate), another assumption that needs to be respected in order to use the Taguchi method.…”

An Assessment of the Chemical Compatibility of Viton Fluoropolymers and Some Harsh Organic Liquid Mixtures

“…The calculated χ parameter for the pure liquids and toluene, methanol, and cyclohexane mixtures through Viton elastomers, obtained from Equation ( 8), is presented in Table 6. The densities used for the calculation were collected from the literature [15,[24][25][26][27].…”

“…The permeation process depends on the transport molecules in the polymeric chain membrane and occurs in three different steps: the molecule dissolves at the membrane face, then diffuses until it reaches the other face, where it evaporates or is extracted [13]. In the case of an elastomeric membrane, e.g., an O-ring, a sealing is usually applied to prevent or control mass leaking; permeation due to long exposure to aggressive organic chemicals may influence the material's structural integrity and performance [15,16]. Typically, permeation experiments are conducted by submerging the polymer sample in a pure solvent volume while maintaining a constant temperature and pressure.…”

“…This study aims to verify the compatibility of Viton fluoroelastromers with aggressive organic liquid mixtures and our current interest arises from the fact that Viton O-rings, although designed for high resistance to individual hydrocarbons, show a noticeable permeation rate when long exposed to mixtures that can result in leakage [15,16] and/or swelling, thus leading to potential damages in industrial equipment and consequently deviations in the expected results. This is of major importance for chemical processing uses, where it is likely that a real application involves solvent mixture, but also for scientific research once instrumentation involves the manipulation of small volumes and high precision is required.…”