Modification of polyvinylchloride by the silicates on the base of rice husk

As a modifying additive in PVC-compositions, silicates produced by means of rice husk processing are of practical interest. Rice husk ash obtained by burning at 350°C, along with synthetic and naturally occurring wollastonite, significantly reduce plasticizer’s migration from the PVC-composition due to their porosity. This is due to the fact that the part of hydroxyl components of the plasticizer EDOS has adsorbed on the surface or retained by the silicates pores. Along with that, Miwoll 10-97 ensures a greater decrease in plasticizer’s migration than synthetic calcium silicate on the base of rice husk ash. When all the researched silicates are modified by the rice husk and naturally occurring wollastonite, heat stability of PVC-compositions grows. This is preconditioned by the alkaline origin of the surface of filling compounds that allows their possible reaction with chlorine hydride released from PVC during thermal decomposition. Synthetic and naturally occurring wollastonite enhance strain-strength properties of PVC-compositions whereas silicates on the case of rice husk reduce these parameters.