| Self-association equilibrium constants for poly(hexafluoroisopropanol styrene) (PHFPS), poly(hydroxy ether of bis-phenol A) (phenoxy), poly(ethylene-co-vinyl alcohol) (EVOH), hexafluoroisopropanol modified polyisoprene (PHFPI), poly(2,6-diisopropyl-4-vinyl phenol) (PDIPPh) and poly(2,6-dimethyl-4-vinyl phenol) (PDMPh) were determined by infrared spectroscopic measurements from appropriate model compounds. Corresponding inter-association equilibrium constants describing the hydrogen bond formation between the above polymers and polymers containing ester or acetoxy groups were determined from infrared studies of miscible polymer blend systems. From these self and inter-association equilibrium constants theoretical miscibility windows, maps and phase diagrams were calculated using the association model developed by Painter and Coleman, for a number of binary polymer blends involving PHFPS, phenoxy, EVOH, PHFPI and PDIPPh. The predicted phase diagrams were experimentally tested using FT-IR and DSC, and, in general, theory and experiment agree very well. The relative magnitude of the equilibrium constants describing self-association versus inter-association was found to be an important factor in determining the phase behavior of hydrogen bonding polymer blends. Finally, from studies of sterically hindered phenolic polymers it was possible to design a miscible polymeric antioxidant for poly(tetrahydrofuran). |
