STUDY OF THE MISCIBILITY AND SPECIFIC INTERACTIONS BETWEEN POLY(1-VINYL-2-PYRROLIDONE) AND POLY(VINYL FORMAL)

The phase behaviour of blends of poly(1-vinyl-2-pyrrolidone) and poly( vinyl formal) was studied by means of differential thermal analysis an d differential mechanical thermal analysis. Both techniques showed tha t the blend studied exhibits a single glass transition, which is inter mediate between the glass transitions associated with each constituent polymer and depends on polymer concentration. Discussion of this phas e behaviour in terms of various common equations is also carried out. The blend preparation method as well as the blend thermal history are found to exert a relevant influence on the phase behaviour associated with the polymer alloy studied here. This behaviour is explained as th e consequence of hydrogen-bonding interactions between both polymers a s demonstrated by infra-red spectroscopy. An additional study on the m echanism of complex formation associated with poly(1-vinyl-2-pyrrolido ne) and poly(vinyl butyral) is also carried out.