Construction of Sequence-Regulated Vinyl Copolymers via Iterative Single Vinyl Monomer Additions and Subsequent Metal-Catalyzed Step-Growth Radical Polymerization

A series of sequence-regulated vinyl copolymers with high-order and long vinyl monomer sequences were constructed via a combination of iterative single vinyl monomer additions, which were mediated by radical and cationic intermediates, and subsequent metal-catalyzed step-growth radical polymerization. The construction of vinyl monomer sequences was attained by iterative single monomer radical and cationic additions between a dichloride, having a similar substituent to that of vinyl monomers, and vinyl monomers such as styrenes, acrylates, and acrylonitrile. The resulting products were converted into sequence regulated ab-type monomers that have embedded vinyl monomer sequences between an unconjugated C=C bond and reactive C-Cl bond via selective allylation of one of the two C-Cl bonds at their terminals. The synthesized sequence-regulated ab-type monomers were polymerized via metal-catalyzed step-growth radical polymerization, which resulted in vinyl chloride units via repetitive intermolecular addition reactions between the C=C and C-Cl terminals. Alternatively, aa- and bb-type sequence-regulated monomers, which have two unconjugated C=C and two reactive C-Cl bonds, respectively, were prepared by similar iterative single monomer additions and were subsequently polymerized via metal-catalyzed step-growth radical polymerization. The repeating vinyl monomer sequence codes in the resulting polymers, such as ABCC, ABCD, ABBAC, ABDBAC, and ABDBACAEEAC, varied from 4 to 11 monomer units in which the embedded vinyl monomer units were styrenes, acrylates, acrylamides, acrylonitrile, vinyl chloride, vinylidene chloride, and ethylene.