Miscible Blends of Poly(vinyl phenyl ketone) and Poly(4-vinyl phenol) M. RODRI ´ GUEZ-CASTRO, 1 L. C. CESTEROS, 2 I. KATIME, 2 S. M. NUN ˜ O-DONLUCAS 3 1 Departamento de Quı ´mica, Universidad de Guadalajara, Boul. M. Garcı ´a Barraga ´n No. 1451, Guadalajara, Jal. 44430, Me ´xico 2 Grupo de Nuevos Materiales y Espectroscopia Supramolecular, Departamento de Quı ´mica Fı ´sica, Facultad de Ciencias, Campus de Leioa, Universidad del Paı ´s Vasco, Apartado 644, Bilbao 48990, Spain 3 Departamento de Ingenierı ´a Quı ´mica, Universidad de Guadalajara, Boul. M. Garcı ´a Barraga ´n No. 1451, Guadalajara, Jal. 44430, Me ´xico Received 28 November 2005; revised 13 May 2006; accepted 1 June 2006 DOI: 10.1002/polb.20893 Published online in Wiley InterScience (www.interscience.wiley.com). ABSTRACT: An analysis by differential scanning calorimetry, modulated differential scanning calorimetry, and Fourier transform infrared spectroscopy (FTIR) indicates that blends of poly(vinyl phenyl ketone) (PVPhK) and poly(4-vinyl phenol) (P4VPh) are miscible at ambient temperature. Miscibility, ascertained, is supported by the ex- istence of a single glass transition for each composition of the PVPhK/P4VPh blends. The FTIR spectroscopy analysis demonstrates the formation of hydrogen bonds between carbonyl groups of PVPhK and hydroxyl groups of P4VPh. This specific interaction has a crucial role on the miscibility behavior of PVPhK/P4VPh blends. The evolution of the glass transition of the PVPhK, P4VPh, and its blends as a func- tion of mixture composition shows negative deviations with to respect to the ideal mixing rule, and both Fox and Gordon–Taylor equations predict this behavior suc- cessfully. V V C 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 2404–2411, 2006 Keywords: hydrogen bonding; infrared spectroscopy; miscible blends; poly(4-vinyl phenol); poly(vinyl phenyl ketone) INTRODUCTION Systematic studies with polymer mixtures, where the parent polymers form hydrogen bonds between their complementary chemical groups, point out that this type of specific interaction acts as a driv- ing force for the polymer–polymer miscibility. 1 Sev- eral factors affect the formation of hydrogen bonds in polymer binary mixtures, for example, the ster- eoregularity of the polymer chains, 2 the type of chemical groups included in the parent polymers, 3 and the possible self-association and/or interassoci- ation of one or two components of the blend. 1 For polymer binary blends where one compo- nent develops self-association by hydrogen bonds while the other component contains only acceptor proton groups, the balance between self-associa- tion and interassociation plays a crucial role on miscibility. 1 Also, the balance between usual un- favorable contributions as dispersion and weak polar forces, and often favorable contributions of some specific interaction as hydrogen bonds, dipole–dipole, random dipole-induced dipole, ion- dipole or charge transfer, strongly affects the phase behavior of polymer blends. 4 Poly(vinyl phenyl ketone) (PVPhK) is an amor- phous, neutral, unsaponifiable ketone polymer. Correspondence to: S. M. Nun ˜ o-Donlucas (E-mail: gigio@ cencar.udg.mx) Journal of Polymer Science: Part B: Polymer Physics, Vol. 44, 2404–2411 (2006) V V C 2006 Wiley Periodicals, Inc. 2404