Measurement of Gas Solubility for PP/Blowing-Agent Mixtures 2005-01-1671
Determination of the solubility of a blowing agent, i.e. supercritical CO2 or N2, in polypropylene (PP) is crucial for achieving high-quality PP and thermoplastic polyolefin (TPO) foams. A magnetic suspension balance (MSB) was employed in the experiments to measure the apparent solubility, while the swollen volume predicted by the Sanchez-Lacombe (SL) equation of state (EOS) and Simha-Somcynsky (SS) EOS was used to account for the buoyancy effect. The gas solubilities for both linear and branched PP were calculated and the effects of branching on the swollen volume and gas solubility were discussed.