40 research outputs found
Evaluation of enthalpy of mixing by calorimetric method: effect of hydrogen bonding in poly(4-hydroxy styrene) based blends
To verify the effect of hydrogen bonding on the polymer mixing, blends
of poly(vinyl methyl ether) (PVME) and poly(methyl methacrylate) (PMMA) with
poly(4-hydroxy styrene) (PHS), respectively, have been prepared. The effect of
hydrogen bond strength on the enthalpy of mixing, DHM, was investigated by
microcalorimetric measurements and FTIR spectroscopy. Infrared analysis allowed
to measure the amount of hydrogen bonding by a curve fitting procedure in PHS/
PMMA blends, looking to the change in the characteristic bands of carbonyl group
of PMMA. In the case of PHS/PMVE, the hydroxyl-stretching region has been
investigated to have only a qualitative estimation of hydrogen bonding. For both
PHS/PMVE and PHS/PMMA systems, the measured exothermic (negative) DHM
decreases with the increase in the PHS content, indicating that the presence of
strong specific intermolecular interactions, such as hydrogen bonding, favours the
polymer blending