Polyaddition of bifunctional 1,3‐benzoxazine and 2‐methylresorcinol

Abstract

A polyaddition system consisted of a bifunctional N‐n‐propyl benzoxazine and 2‐methylresorcinol (MR) that proceeds at ambient temperature has been developed. In this system, the aromatic ring of MR acted as a bifunctional monomer, reacting with a two equivalent amount of benzoxazine moieties via their ring‐opening reaction. The polyaddition gave the corresponding linear polymer bearing phenolic moieties bridged by Mannich‐type linkage in the main chain. The linear polymer had a high glass transition temperature, which was comparable to that of the linear polybenzoxazine synthesized by the ring‐opening polymerization of a monofunctional N‐n‐propyl benzoxazine. The employment of a bifunctional N‐allyl benzoxazine in the polyaddition system resulted in the formation of the corresponding polymer with allyl pendants, which exhibited improved heat resistance due to its thermally induced crosslinking reaction. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2013, 51, 3867–3872

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.…”

“…[19][20][21][22][23][24][25][26][27][28][29][30][31][32] To cure 1,3-benzoxazines, thermally accelerated polymerization has been the main focus for most researchers for a long time. To date, very few compounds, including phenolic compounds, [39][40][41][42][43][44] thiols, [45][46][47][48][49] benzimidazoles, 50 benzoxazoles, 26,51,52 chitosan ammonium, 53 and some polymers containing aromatic structures 19,21,23 have been reported to construct chemical linkages with benzoxazines. 19,20,[33][34][35] The basic concept of the reaction mechanism is the protonation of the oxygen atom in the oxazine ring, followed by the formation of a zwitter iminium ionic structure, and its subsequent Scheme 1 The polymerization mechanisms of benzoxazine proposed by previous reports.…”

Resorcinol‐based benzoxazine with low polymerization temperature

“…They may also show different reactivity toward benzoxazines. Recently, Oie et al demonstrated a new approach to form polybenzoxazines due to ring‐opening addition . This reaction of a benzoxazine ring with 2‐methylresorcinol occurs at ambient conditions and is therefore a promising concept.…”

Synthesis and properties of organo-gels by thiol-benzoxazine chemistry

“…In the same study, the application of this reaction to a new polyaddition-depolymerization system was also performed yielding linear polymers. [37] Another useful application concerns construction of a highly efficient curing system. Crosslinked but additionally curable soft benzoxazine films were prepared by simultaneous photoinduced thiol-ene and COLBERT reactions using difunctional thiol and diallybenzoxazine.…”