Synthesis and properties of few polyphosphonate derivatives containing photosensitive unsaturated keto group in the main chain

A series of homo and copolyphosphonate derivatives were synthesized by interfacial polycondensation reactions of 1,3-bis(4-hydroxyphenyl)propenone with phenylphosphonic dichloride and terephthaloyl chloride, and 3-(4-hydroxy-3-methoxyphenyl)-1-(4-hydroxyphenyl)propenone with phenylphosphonic dichloride and terephthaloyl chloride using a phase transfer catalyst at ambient temperature. The diol monomers were prepared by condensing 4-hydroxy benzaldehyde and 3-methoxy-4-hydroxybenzaldehyde with 4-hydroxy acetophenone. The structures of the synthesized monomers and polymers were confirmed using UV, IR and H-1, C-13, and P-31 NMR spectroscopic techniques. The molecular weights of the polymers were determined by gel permeation chromatography. The thermal properties of the polymers were studied by thermogravimetric analysis and differential scanning calorimetry under a nitrogen atmosphere. The photosensitive property of the polymers in films and solution states was investigated by ultraviolet spectroscopy. Photocrosslinking proceeded via a 2 pi+2 pi cycloaddition reaction of alpha,beta-unsaturated carbonyl group. The chemical and physical properties of methoxy substituted polymers were compared to those of the unsubstituted polymers. The structure-property relationships and flame retardant characteristics of the synthesized polymers were also studied.