Thiol‐functionalized 1,3‐benzoxazine: Preparation and its use as a precursor for highly polymerizable benzoxazine monomers bearing sulfide moiety

Abstract

We describe a new strategy for preparation of benzoxazine monomers based on in situ preparation of a thiol‐functionalized benzoxazine and successive chemical modification of the thiol moiety. The thiol‐functionalized benzoxazine can be prepared from its precursor bearing two benzoxazine moieties linked by disulfide bond. Reductive cleavage of the disulfide bond of the precursor with using triphenylphosphine as a reducing agent allows successful preparation of the thiol‐functionalized benzoxazine. By performing this reduction process in the presence of epoxides and acrylates, the formation of the thiol moiety and its successive reaction with those electrophiles proceed efficiently to give the corresponding benzoxazines with sulfide moieties. The benzoxazine monomers thus prepared exhibit much higher polymerization ability than those without sulfide moiety. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014, 52, 1448–1457

Radical and Atom Transfer Halogenation (RATH): A Facile Route for Chemical and Polymer Functionalization

“…As it has been reported that the polymerization does not alter the benzoxazine ring group, the obtained PMMA chains still possess chemically active benzoxazine groups observed with 1 H NMR analysis (see supporting materials). As a result, further reaction and modification on the benzoxazine‐possessing PMMA could be performed such as self‐polymerization and thiol‐addition reaction …”

“…[12][13][14][15][16] The sequential ATRP results in polymer chains possessing benzoxazine groups, which could be further functionalized with other agents [ 20,21 ] or self-crosslinked. [12][13][14][15][16][17][18][19][20][21][22][23][24] RATH provides great convenience for preparation of functional initiators of atom transfer radical polymerization (bromination of benzoxazine compounds and PPO have been carried out with the RATH reaction using 1-(bromoethyl)benzene (BEB) as the alkylhalide reagents, CuBr as the catalyst, and 2,2′-bipyridyl as the ligand. Using bis(3-furfuryl-3,4-dihydro-2H-1,3-benzoxazinyl)isopropane (BPA-FBz) [ 25 ] as an example of RATH reagent, the solutions of all the chemicals in deuterated dimethylsulfoxide (DMSO-d 6 ) have been applied to 1 H NMR measurements to trace the RATH reaction between BPA-FBz and BEB.…”

“…benzoxazine-possessing PMMA could be performed such as self-polymerization [ 28 ] and thiol-addition reaction. [ 21 ] The brominated PPO (PPO-Br) is also used as an initiator for atom transfer radical polymerization of methylmethacrylate (MMA) to result in the graft copolymer of PPO-g-PMMA (see Supporting Information). After bromination, the number-averaged molecular weight (Mn) of the PPO sample slightly increases from 4,590 to 4,920 g mol −1 .…”

A curing system of benzoxazine with amine: reactivity, reaction mechanism and material properties

“…A recent report has demonstrated a competitive pathway through phenoxy structures that nally convert to the phenolic polymers upon heating up to 160 C. 35 Furthermore, some special compounds, such as phenolic compounds, thiols, and chitosan ammonium, were used to react with benzoxazines 42,46,49,53,59,60 and a new mechanism, described as a ring-opening addition reaction mechanism (Scheme 1b), has been proposed. A recent report has demonstrated a competitive pathway through phenoxy structures that nally convert to the phenolic polymers upon heating up to 160 C. 35 Furthermore, some special compounds, such as phenolic compounds, thiols, and chitosan ammonium, were used to react with benzoxazines 42,46,49,53,59,60 and a new mechanism, described as a ring-opening addition reaction mechanism (Scheme 1b), has been proposed.…”

Study on an amine-containing benzoxazine: Homo- and copolymerization with epoxy resin

“…Another method is to incorporate reactive groups, such as amine, onto the Bz structures. But, only few studies have been reported until now due to relatively tedious preparation procedure [21,22].…”