The present invention relates to a polymer comprising: (a) polymeric units derived from vinyl chloride, vinyl acetate, styrene, methyl methacrylate, acrylonitrile, or combinations thereof; and (b) polymeric units derived from one or more compounds according to formula I: wherein: R1 is CH3 or H; R2 is a moiety comprising 1-20 carbon atoms; and n is an integer from 1-10; wherein the polymer has an average particle size of 10-80 μm expressed as D50 determined in accordance with ISO 9276-2 (2014); and a porosity of ≤0.20 ml/g as determined as the quantity of di(2-ethylhexyl)phthalate in ml absorbed by 1 g of polymer upon subjecting the polymer at 23° C. to vacuum, submerging in di(2-ethylhexyl)phthalate for 10 min, and subsequently centrifuging at 2000 rpm for 45 min. Such polymer may be used as viscosity reducing agent in PVC plastisol compositions.