Macromolecular Rapid Communications, Vol.23, No.18, 1130-1133, 2002
Quantifying polymer swelling employing a linear variable differential transformer: CO2 effects on SBS triblock copolymer
A linear variable differential transformer (LVDT) was employed to evaluate CO2-polymer plasticization. Preliminary results on polystyrene-block-polybutadiene-block-polystyrene (SBS) elastomer are presented. At 22degreesC under CO2 pressure, SBS undergoes compression due hydrostatic pressure. However, sample expansion occurs upon depressurization.At 45degreesC, SBS undergoes swelling of 0.7% due to CO2 plasticization, while no post-pressurization expansion is observed. The contrasting result is explained by change in PS domain mobility and discontinuity in the density-pressure relationship.