A polyvinyl chloride (PVC) composition and a method for preparing a polymer composite article. The composition comprises (A) a mineral filler in an amount of from 7.5 to 75 wt. %. The composition also comprises (B) a polyvinyl chloride polymer in an amount of from 20 to 92 wt. %. Further, the composition comprises (C) a polydiorganosiloxane in an amount of from greater than 0 to 5 wt. %; the (C) polydiorganosiloxane being a compound of formula (I): where each R is an independently selected monovalent hydrocarbon group of 1 to 18 carbon atoms that is free of aliphatic unsaturation, and subscript x has a value sufficient to give the (C) polydiorganosiloxane a viscosity of greater than 350 mPa·s to 100,000 mPa·s measured at 25° C. at 0.1 RPM to 50 RPM on a Brookfield DV-III cone & plate viscometer with #CP-52 spindle. The ranges for components (A)-(C) are based on the total weight of components (A), (B) and (C) in the composition.