Thermodynamic analysis of a phase separation induced by a free radical polymerization: blends of poly(isobutylene) and poly(isobornylmethacrylate)

E. R. SOULÉ; J. BORRAJO; R. J. J. WILLIAMS

Río de Janeiro, Brasil

Congreso; World Polymer Congress - Macro 2006; 2006

IUPAC

The miscibility of different polyisobutylene oligomers (PIB) in mixtures of isobornylmethacrylate (IBoMA) and poly(isobornylmethacrylate) (PIBoMA), at 80 ºC, was determined either employing physical mixtures of the three components or from the cloud-point conversion during the polymerization-induced phase separation of solutions of PIB in IBoMA. Results obtained with both methods were in reasonable agreement. The phase diagram was predicted with the Flory-Huggins (F-H) model taking into account the polydispersities of PIB and PIBoMA. The interaction parameters of the three pairs IBoMA/PIB, PIBoMA/PIB and IBoMA/PIBoMA, were obtained from cloud-point curves of binary or ternary mixtures. Using the F-H model with these interaction parameters enabled to reproduce the experimental phase diagram at 80 ºC.  The possibility of predicting cloud-point conversions and critical compositions for different formulations and polymerization temperatures can be used to control the morphologies generated in the course of a polymerization-induced phase separation.