Patent ID: 8211989

Claim:
A method of preparing a crosslinked polymer, wherein the method comprises polymerising branched polyunsaturated monomers by a metathesis polymerisation reaction, wherein the branched polyunsaturated monomers comprise at least a general structural unit (I): BR 1 R 2 R 3 (I) where B represents an atom or core, and where each moiety R 1 , R 2 and R 3 , which may be the same or different, contains at least one acyclic ethylenically unsaturated group which (a) is located within 6 atoms from the end of the moiety, and (b) is capable of undergoing polymerization by a metathesis reaction such that the metathesis polymerisation produces a crosslinked polymer and substantially no non-volatile ethylenically unsaturated by-products, wherein the branched polyunsaturated monomers are, or are derived from, a natural oil.