Effect of the nature of a polymer matrix on the enthalpy of adhesion interactions in composites filled with nickel nanoparticles

Abstract

Interfacial interactions in composites filled with nickel nanoparticles are studied experimentally. The concentration dependences of the enthalpy of mixing of rubbery and glassy homo- and copolymers of different polarities with nickel nanoparticles coated with a carbon shell are measured via isothermal calorimetry. On the basis of these data, the values of adhesion and the structural contributions to the enthalpy of mixing are calculated. A decrease in the kinetic flexibility of macromolecular chains with an increase in the glasstransition temperature of the polymer causes a gain in the positive structural contribution to the enthalpy of mixing of the composite. The contribution of adhesion interaction is negative and predominantly determined by electrostatic forces of the induction type. The maximum enthalpy of adhesion is proportional to the squared dipole moment of a polymer unit and independent of the relaxation state of the polymer matrix.