TITLE:
Miscibility Behavior of Polyacrylamides Poly(Ethylene Glycol) Blends: Flory Huggins Interaction Parameter Determined by Thermal Analysis
AUTHORS:
Maria Elisa S. R. Silva, Valdir Mano, Raquel R. J. Pacheco, Roberto F. S. Freitas
KEYWORDS:
Polyacrylamides; Poly(Ethylene Glycol); Polymer Blends; Flory-Huggins Interaction Parameter; Differential Scanning Calorimetry
JOURNAL NAME:
Journal of Modern Physics,
Vol.4 No.7B,
July
18,
2013
ABSTRACT:
Blends of polyacrylamide—PAM, poly(N-isopropylacrylamide)—PNIPAAm, poly(N-tert-butylacrylamide)—PTBAA, poly(N,N-dimethylacrylamide)—PDMAA
and poly(N,N-diethylacrylamide)—PDEAA with poly(ethylene glycol)— PEG were
prepared by casting in methanol and water at concentrations of 20 wt%, 40 wt%,
60 wt%, and 80 wt% in PEG. The miscibility of the components was studied by
Differential Scanning Calorimetry—DSC. All blend systems are characterized by a
single glass transition temperature (Tg),
close to the Tg of the
amorphous component. The Hoffman Weeks method was used to determine equilibrium
melting temperature (Tm)
data. The determination of the melt point depression of the blends allowed the
calculation of Flory-Huggins interaction parameter (χ12) of the two polymers in the melt, by using the Nishi
Wang equation. The interaction parameters, calculated for all the blends, are
slightly negative and close to zero, suggesting a partial miscibility between
the components.