Influence of N-alkyl and α-substitutions on the thermal behaviour of H-bonded interpolymer complexes based on polymers with acrylamide or lactame groups and poly(4-vinylphenol)

Thermal stability of H-bonded interpolymer complexes between polymers with acrylamide or lactame groups and poly(4-vinylphenol) (PVPh) has been analysed. Poly(N-isopropylacrylamide) (PNiPAm) has been chosen as a reference in order to study the effect of the substituent on the N-alkyl or α-methyl substitutions in the properties of these materials. The glass transition temperature of the interpolymer complexes is higher than their polymer components due to the hydrogen bond formation between their chains. The complexation process improves the glass transition temperature and stability, a maximum increase in the glass transition temperature for the complexes from disubstituted amides and from the bulkier lactame being obtained.