An oligomer-polymer composition comprising oligomer composition O having a weight average molecular weight of from 1000 to 150,000 g/mol (measured by GPC) and polymer composition P having a weight average molecular weight of at least 80,000 g/mol (measured by GPC) the oligomer composition O and the polymer composition P each independently comprising a copolymer composition comprising: (a) optionally at least 24 % by weight of at least one monomer represented by Formula 1 where both R 1 and R 2 independently represent an optionally substituted hydrocarbo moiety having from 4 to 10 carbon atoms, (b) optionally at least one acid functional monomer in an amount from 0.5 to 15% by weight and also in an amount sufficient that the resultant polymer has an acid value from 3 to 100 mg KOH per g of polymer, (c) optionally one or more monomers represented by Formula 2 where X 1 and X 2 are O and R 3 and/or R 4 attached to the oxy group independently represent an optionally substituted hydrocarbo having from 1 to 3 carbon atoms, (d) optionally less than 75 % by weight of monomers other than components (a), (b) or (c), where the percentages or amounts of (a), (b) (c) (d) are by weight calculated as a proportion of the total weight of (a) + (b) + (c) + (d) and thus total 100%; where independently at least one of the components (a), (b) (c) and/or (d) and/or the copolymer obtained from them are biorenewable defined as comprising an amount of carbon-14 sufficient to produce a decay of at least about 1.5 dpm/gC (disintegrations per minute per gram carbon); and where at least one component (a) is present in either oligomer composition O or polymer composition P, and where the oligomer-polymer composition comprising (a) component (a) in an amount from 24 % to 70% by weight being one or more monomers represented by Formula 1, (b) component (b) being one or more acid functional monomer(s) in an amount from 0.5 % to 15 % by weight, in an amount also sufficient that the resultant polymer has an acid value of from 3 to 100 mg KOH per g of polymer, (c) component (c) in an amount from 0.01 % to 10% by weight, (d) component (d) if present in an amount less than 75% by weight of monomer(s) other than components (a), (b) or (c) and does not contain styrene, butyl acrylate, 2-ethyl hexyl acrylate or mixtures thereof; with the provisos that where the copolymer is prepared by an emulsion polymerisation a chaser monomer is not used; the copolymer is not prepared in the presence of a seed polymer comprising a poly(itaconate ester); the copolymer is not prepared in the presence of an initiator system comprising an organoborane amine complex. (a) optionally at least 24 % by weight of at least one monomer represented by Formula 1 where both R 1 and R 2 independently represent an optionally substituted hydrocarbo moiety having from 4 to 10 carbon atoms, (b) optionally at least one acid functional monomer in an amount from 0.5 to 15% by weight and also in an amount sufficient that the resultant polymer has an acid value from 3 to 100 mg KOH per g of polymer, (c) optionally one or more monomers represented by Formula 2 where X 1 and X 2 are O and R 3 and/or R 4 attached to the oxy group independently represent an optionally substituted hydrocarbo having from 1 to 3 carbon atoms, (d) optionally less than 75 % by weight of monomers other than components (a), (b) or (c), (a) component (a) in an amount from 24 % to 70% by weight being one or more monomers represented by Formula 1, (b) component (b) being one or more acid functional monomer(s) in an amount from 0.5 % to 15 % by weight, in an amount also sufficient that the resultant polymer has an acid value of from 3 to 100 mg KOH per g of polymer, (c) component (c) in an amount from 0.01 % to 10% by weight, (d) component (d) if present in an amount less than 75% by weight of monomer(s) other than components (a), (b) or (c) and does not contain styrene, butyl acrylate, 2-ethyl hexyl acrylate or mixtures thereof;