Thermomechanical investigation of a thick film of aniline-formaldehyde copolymer and poly(methyl methacrylate)

A thick film of aniline-formaldehyde copolymer and PMMA is synthesized via dispersion of aniline-formaldehyde copolymer powder as filler particles in PMMA with two different concentrations. Variation of the complex elastic modulus and mechanical loss factor (tan delta) with temperature is studied. It is observed that the complex elastic modulus decreases with temperature owing to thermal expansion of films. On the other hand, tan delta increases up to a characteristic temperature beyond which it shows a decreasing trend toward melting. Transition temperature T-g of sample S-1 (pure PMMA) is found to be 80 degrees C. In sample S-2 (1 wt % aniline formaldehyde copolymer), the peak of tan delta at a lower temperature (66 degrees C) corresponds to glass transition temperature Tg of the PMMA matrix, while the peak of tan delta at a higher temperature (107.8 degrees C) corresponds to T-g of a polymer chain restricted by filler particles of aniline-formaldehyde copolymer. A further increase (10 wt % aniline-formaldehyde copolymer) in the concentration of filler particles of aniline-formaldehyde copolymer results in a more compact structure and a shift of Tg to a higher temperature, 122.2 degrees C. This shift in the glass transition temperature of thick films of aniline-formaldehyde copolymer and PMMA is dependent upon the concentration of filler particles in the sample.