title: Determining the solubility parameter and the cross-link density of medical grade silicones: effect of increasing the range of swelling liquids.
abstract: Four samples of four medical grade silicones were swollen in six "good" liquids (i.e. those with a good swelling ability, in which silicones swell appreciably) at 25°C, until they reached constant mass (i.e. equilibrium). The volume fraction, ϕ, of the silicone in the swollen sample was calculated for each grade of silicone. Using a combination of the six ϕ values obtained in this study and four of those obtained in a previous study, for each silicone grade, ϕ was plotted against δl, the liquid solubility parameter for the ten liquids used. Using a curve fitting technique a second-order polynomial was plotted through the data points; the minimum in this polynomial provided a value for δp (the polymer solubility parameter). Furthermore, the results showed that the δp values obtained in this study (using ten liquids) were slightly but significantly greater (p<0.05) than those obtained in a previous study (using four liquids), for grade C6-165 only. Similarly, the χ and υ values obtained in the two studies were only significantly different (p<0.05) from each other, for grade C6-165.
authors: School of Mechanical Engineering, University of Birmingham, Edgbaston, Birmingham, UK.
authors: Aziza
authors: A
authors: Mahomed
authors: School of Mechanical Engineering, University of Birmingham, Edgbaston, Birmingham, UK.
authors: Areg
authors: A
authors: Kocharian
mesh_terms: D001672:Biocompatible Materials / Q000737:chemistry*; D003510:Cyclohexanes / Q000737:chemistry; D006536:Heptanes / Q000737:chemistry; D009795:Octanes / Q000737:chemistry; D011108:Polymers / Q000737:chemistry; D012828:Silicones / Q000737:chemistry*; D012995:Solubility; D012997:Solvents / Q000737:chemistry; D014050:Toluene / Q000737:chemistry
chemical_list: D001672:Biocompatible Materials; D003510:Cyclohexanes; D006536:Heptanes; D009795:Octanes; D011108:Polymers; D012828:Silicones; D012997:Solvents; D014050:Toluene; C028618:n-heptane; C506365:Cyclohexane; C045798:2,2,4-trimethylpentane
keywords: Cross-link density; curve fitting technique; silicones; solubility parameter; swelling in liquids