Experimental and theoretical evaluation of the reactions leading to formation of internal double bonds in suspension PVC Purmova, Jindra; Pauwels, Kim F. D.; Agostini, Michela; Bruinsma, Maarten; Vorenkamp, Eltio J.; Schouten, Arend J.; Coote, Michelle L.

Similarly to most graft polymers, the system examined in this study presents in the solid state two phases, each of which can be spread out or entangled. If the spreaded compound is present in sufficient proportion, it forms the continuous phase and its nature determines the macroscopic properties of the graft copolymer. The graft copolymers were prepared using the preozonizations technique with backbone and graft being alternatively ethyl polyacrylate (PAE) and a styrene‐maleic anhydride copolymer (PSAM). The phases separation is taken in evidence with the electron microscope. The influence of the nature of the continuous phase on the chemical properties is shown by dynamometric measurements. The differential thermal analysis shows that there is no ship of the glass transition temperatures (Tg) with respect to those of both homopolymers, but that the entropy changes at the transition are function of the spreading out of the polymer chains. Dielectric relaxation measurements show an absorption identical to that of the α relaxation of PAE. In a graft copolymer where PSAM is the continuous phase and therefore appears to be rigid, the entangled chains of PAE of the discontinuous phase possess a higher mobility than when they form the continuous phase.