Phase behaviour and structure formation in solutions of poly(4-methyl-1-pentene) in cyclohexane

The phase behaviour of the system poly(4-methyl-1-pentene)/cyclohexane was investigated. At low polymer concentration, transparent gels are obtained by formation of a polymer-solvent compound (modification V). The molecular conformation is different from the one encountered during melt crystallization (modification I). In the higher concentration range, competition between folded chain lamellar crystallization and the formation of this compound takes place and the final situation depends strongly on the experimental conditions like cooling rate. Isothermal swelling experiments clearly illustrate the transition from modification I to V by a peritectic reaction. Drying leads to modification III, that transforms in modification I on heating. The composition of the polymer-solvent compound was estimated at a molar ratio monomer unit/solvent molecule = 1.