Patent ID: 8691894

Claim:
A process for preparing a polyamide block copolymer comprising the steps in sequence of: (a) contacting at least one cyclic amide having a melting point lower than about 260° C. with either catalyst (A) or catalyst (B), wherein catalyst (A) comprises any one or more of the N-heterocyclic carbene-containing compounds described generally by the Formulae I, II and III: wherein: R 1 , R 5 , R 9 and R 11 are each independently an adamantyl, alkaryl, or alkyl group; R 2 , R 3 , R 6 , R 7 and R 10 are each independently hydrogen or a C 1-12 alkyl group; n=1 or 2; R 4 is the same as R 1 when n=1 and is an alkylene group when n=2; and R 8 is the same as R 5 when n=1 and is an alkylene group when n=2; and catalyst (B) is a mixture or an adduct of catalyst (A) and any one or more of the compounds described generally by the Formulae IV, V, VI and VII: wherein R 12 , R 13 , R 14 and R 15 are each independently a C 1-12 aliphatic hydrocarbyl or substituted aliphatic hydrocarbyl group; and R 16 , R 17 , R 18 , R 19 and R 20 are each independently a C 1-12 alkyl group; (b) heating a cyclic amide with catalyst (A) or (B) at or above the melting point of the cyclic amide for a time sufficient to polymerize the cyclic amide to produce a linear polyamide; (c) optionally, cooling the product of step b; (d) contacting a second cyclic monomer with the product of step b or c wherein the second monomer is one or more of macrocyclic polyester oligomers, epoxides, macrocyclic oligomers of polycarbonate, or lactones; and (e) heating the second monomer with the product of step b or c at or above the melting point of the second monomer for a time sufficient to produce a linear copolymer of a cyclic amide and the second monomer, wherein the linear copolymer is a block copolymer characterized by a percent randomization of less than about 50%.