摘要：

The excellent thermal and mechanical properties of benzoxazine resin attracted much academic and industrial attention [1,2]. Very recently, the interest in the new generation of the benzoxazines, main- chain type benzoxazine polymers, in which benzoxazine is a repeating unit in the main chain is growing rapidly because it combines the advantages of thermoplastic and thermosetting polymers [3-5]. Polyurethane (PU) is one of the most attractive polymers of segmented structure consisting of soft segments derived from polyols and hard segments derived from isocyanates and chain extenders. PU-modified polybenzoxazine has actively studied to obtain high performance elastic materials [6-8]. A common approach for PU/polybenzoxazine materials is based on blending PU prepolymer with polybenzoxazine precursors. The produced phenolic groups from the ring opening polymerization are expected to react with NCO group in the PU prepolymer, forming crosslinked polymers. In continuation of our ongoing studies for producing main chain benzoxazine polymers with various architecture and hence of different properties, we reported on a new approach to incorporate polyurethane (PU) segment into benzoxazine structure. This new approach is based on preparation of main-chain type poly(benzoxazine-urethane) via copolymerization of dimethylol–functional benzoxazine monomer with diisocyanate monomers and polyethylene glycol to afford a linear polymer. Thus, a soluble elastic polymers can be produced which can be processed in the film or applied for coating application without the complications of NCO-terminated PU polymer in the traditional polymer blend.

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