A method of forming a polymer coated sulphur cured rubber composition including: providing a sulphur curable rubber composition comprising a compound including at least one thiol group, and/or contacting a sulphur curable rubber composition with a compound including at least one thiol group, contacting the sulphur curable composition with a second polymeric precursor including a compound of formula A or II: wherein R 6 represents an amine moiety, a quaternary ammonium cation or an optionally substituted hydrocarbyl group, R 20 represents an optionally substituted hydrocarbyl group, group, each of R 1 and R 2 independently represents an optionally substituted hydrocarbyl J is an integer from 1 to 4; wherein each of R 1 and R 2 independently represents an optionally substituted hydrocarbyl group, R 17 and R 18 independently represents an optionally substituted hydrocarbyl group, or hydrogen, y is an integer of from 1 to 3; z is an integer of from 1 to 3; wherein the combination of the integers represented by y and z must be 4 or less, and where the combination of the integers represented by y and z is 3, one of R 17 and R 18 is absent, and where the combination of the integers represented by y and z is 4, both of R 17 and R 18 are absent; X - represents a counter ion; reacting the compound including at least one thiol group and the second polymeric precursors to form a polymeric layer; and curing the sulphur curable rubber composition to form a polymer coated sulphur cured rubber composition. providing a sulphur curable rubber composition comprising a compound including at least one thiol group, and/or contacting a sulphur curable rubber composition with a compound including at least one thiol group, contacting the sulphur curable composition with a second polymeric precursor including a compound of formula A or II: wherein R 6 represents an amine moiety, a quaternary ammonium cation or an optionally substituted hydrocarbyl group, R 20 represents an optionally substituted hydrocarbyl group, group, each of R 1 and R 2 independently represents an optionally substituted hydrocarbyl J is an integer from 1 to 4; wherein each of R 1 and R 2 independently represents an optionally substituted hydrocarbyl group, R 17 and R 18 independently represents an optionally substituted hydrocarbyl group, or hydrogen, y is an integer of from 1 to 3; z is an integer of from 1 to 3; wherein the combination of the integers represented by y and z must be 4 or less, and where the combination of the integers represented by y and z is 3, one of R 17 and R 18 is absent, and where the combination of the integers represented by y and z is 4, both of R 17 and R 18 are absent; X - represents a counter ion; reacting the compound including at least one thiol group and the second polymeric precursors to form a polymeric layer; and curing the sulphur curable rubber composition to form a polymer coated sulphur cured rubber composition. wherein R 6 represents an amine moiety, a quaternary ammonium cation or an optionally substituted hydrocarbyl group, R 20 represents an optionally substituted hydrocarbyl group, group, each of R 1 and R 2 independently represents an optionally substituted hydrocarbyl J is an integer from 1 to 4; wherein each of R 1 and R 2 independently represents an optionally substituted hydrocarbyl group, R 17 and R 18 independently represents an optionally substituted hydrocarbyl group, or hydrogen, y is an integer of from 1 to 3; z is an integer of from 1 to 3; wherein the combination of the integers represented by y and z must be 4 or less, and where the combination of the integers represented by y and z is 3, one of R 17 and R 18 is absent, and where the combination of the integers represented by y and z is 4, both of R 17 and R 18 are absent; X - represents a counter ion; reacting the compound including at least one thiol group and the second polymeric precursors to form a polymeric layer; and curing the sulphur curable rubber composition to form a polymer coated sulphur cured rubber composition. wherein each of R 1 and R 2 independently represents an optionally substituted hydrocarbyl group, R 17 and R 18 independently represents an optionally substituted hydrocarbyl group, or hydrogen, y is an integer of from 1 to 3; z is an integer of from 1 to 3; wherein the combination of the integers represented by y and z must be 4 or less, and where the combination of the integers represented by y and z is 3, one of R 17 and R 18 is absent, and where the combination of the integers represented by y and z is 4, both of R 17 and R 18 are absent; X - represents a counter ion; reacting the compound including at least one thiol group and the second polymeric precursors to form a polymeric layer; and curing the sulphur curable rubber composition to form a polymer coated sulphur cured rubber composition.