Influence of the Temperature on the Viscosity of Different Types of Silicone

Abstract

: The objective of this work was to test the influence of temperature on the viscosity of three silicones of different molecular weights (Biodur® S10, Polisil® P10 and P1) commonly used in the plastination technique. For the study, the RheolabQC model rotational rheometer was used to measure the dynamic viscosities of the chosen polymers at the following temperatures: -5, 0, 5, 10, 15, 20, 25, 30 and 35 °C. From the 9 measurements of viscosities obtained from each sample, a viscosity vs. temperature graph was constructed. The equation of the dynamic viscosity curve of each polymer was analyzed. Polisil® P1 silicone had a much lower viscosity compared to other silicones (about 80 mPa.s at 25 °C and 550 mPa.s at -25 °C). Polisil® P10 silicone presented the highest viscosity of the polymers analyzed (approximately 1180 mPa.s at 25 °C and 3730 mPa.s at -25 °C). The Biodur®'s S10 silicone showed an intermediate viscosity (about 410 mPa.s at 25 ° C and 1500 mPa.s at -25 °C). We conclude that Polisil® P1 silicone presented the best physico-chemical characteristics of the tested silicones for plastination, because it has high fluidity and low viscosity. It is noteworthy that the viscosity of Polisil® P1 in cold impregnation temperature (-15 °C) is still lower than the viscosity of the Biodur® S10 (control) at room temperature (20-25 °C). We also conclude that the knowledge of the intrinsic and extrinsic physicochemical characteristics of the silicone and its dynamic viscosity is helpful in choosing the ideal silicone for use in the cold or room temperature plastination techniques.