The gelation and rigidity modulus of dilute poly(vinyl chloride) gels in phthalate plasticizer solutions

Static elastic moduli of gels of PVC have been obtained in various dialkyl phthalate plasticizers at times between 0.5 and 200 hr after formation, at temperatures between 27 and 45° and for polymer concentrations between 4 and 10.55%. The moduli increase linearly with log (time) and they increase with decreasing temperature, with increasing polymer concentration and with increasing size of the alkyl group of the plasticizer. These changes follow the same pattern as those observed with plasticized PVC at concentrations normally used in commerce. The moduli obtained at the present concentration have been interpreted using rubber-like elasticity theory and a simplified theory of network equilibrium