Cyclic imino ethers in step-growth polymerizations

Abstract

The synthesis of oxazoline and oxazine type monomers is explored, with focus mainly on those methods of most commercial significance. The many varied reactions of cyclic imino ethers with various other functionalities are also discussed, with the main focus being on those reactions most useful to form polymers. The step-growth or polycondensation reaction of cyclic imino ether monomers, oxazoline and oxazine molecules, receives significant attention. For step-growth polymerizations, extensive attention is given to the preparation and reaction of monomers or polymers having ≥2 oxazoline or oxazine residues. Those reactions most useful to prepare thermoplastics or thermosets, which resides in the polycondensation of dicarboxylic acids, dithiols, phenolics, epoxides, etc. with bisoxazolines or bisoxazines receive significant focus. The simultaneous copolymerization of benzoxazines and bisoxazolines with phenolics is also described. Lastly, a variety of oxazoline or oxazine monomers, having acetylacetonate, acetylacetanilide, thiopene, etc. type residues are also described. Clearly, it is shown that there are significant opportunities to use oxazoline or oxazine functionalized monomers, oligomers and polymers to produce new materials for a variety of applications.