Dissolution of polypropylene in organic solvents: 1. Partial dissolution

The dissolution of polypropylene in organic solvents has been investigated in detail. The complete study will provide an interesting comparison with the literature concerning the dissolution of amorphous polymers. Under appropriate conditions polypropylene dissolves at a steady rate, but there is a preliminary induction period. The results reported here concern this period, and provide the foundation for later parts of the work. It was necessary to study solvent sorption by polymer as well as the partial or fractional dissolution characteristic of the induction period. The Hildebrand solubility parameter proved useful in understanding the behaviour of polypropylene soaked in various solvents over a range of temperatures. Factors controlling the partial dissolution have been identified and analysed.