THIOURETHANE POLYMERS, METHOD OF SYNTHESIS THEREOF AND USE IN ADDITIVE MANUFACTURING TECHNOLOGIES
A semi-crystalline thiourethane polymer. The semi-crystalline thiourethane polymer comprises a sequential chain of a first type of monomer covalently bonded to a second type of monomer via thiourethane linkages. Each of the first type of monomer includes two or more thiol functional groups and each of the second type of monomer includes two or more isocyanate functional groups. The first and second types of monomers are polymerized together in an anionic step-growth polymerization reaction that is catalyzed by a non-nucleophillic base having a pKa greater than 7, produced by photo-initiated decomposition of a photolatent base. A method of synthesizing, and polymer jetting and stereolithography methods of manufacturing a polymer part, are also disclosed.
1 . A semi-crystalline thiourethane polymer, comprising:
a sequential chain of a first type of monomer covalently bonded to a second type of monomer via thiourethane linkages, wherein:
each of the first type of monomer includes two or more thiol functional groups and each of the second type of monomer includes two or more isocyanate functional groups, and
the first and second types of monomers are polymerized together in an anionic step-growth polymerization reaction that is catalyzed by a non-nucleophillic base having a pKa greater than 7, the non-nucleophillic base produced by photo-initiated decomposition of a photolatent base.
2 . The polymer of claim 1 , wherein the first type of monomer is free of -ene or isocyanate functional groups and the second type of monomer is free of -ene or thiol functional groups.
3 . The polymer of claim 1 , wherein the first type of monomer only has thiol functional groups and the second type of monomer only has isocyanate functional groups.
4 . The polymer of claim 1 , wherein the first type of monomer has monomers with three or more thiol functional groups and monomers with two thiol functional groups.
5 . The polymer of claim 1 , wherein the second type of monomer has monomers with two isocyanate functional groups.
6 - 20 . (canceled)