| Abstract |
In the present work, the reprocessability of thermosetting polythiourethanes via supercritical CO2 foaming was explored. Firstly, the maximum crosslinking density susceptible to be foamed was determined employing samples with a crosslinking density between 4 center dot 10- 4 and 7.4 center dot 10- 5 mol of crosslinking bonds/g of sample. The foaming conditions explored were 150 bar and 1 h of saturation time with supercritical CO2, and a temperature window of 90 - 130 degrees C. After this test, it was observed that, for the polymers synthesized, the maximum amount of crosslinking density susceptible to be foamed was 1.5 center dot 10- 4 mol of crosslinking bonds/g of sample. This sample was selected as the base sample to perform a deepest study, complemented by a statistical analysis of the results obtained, were the influence of pressure and temperature on the foamability of thermosetting polythiourethanes was explored. After this study, it was concluded that the pressure was the foaming variable with the highest influence on the foam's properties, this influence being powerful enough to be statistically significant in all cases, while the influence of temperature was only significant in the case of expansion ratio. |
