Synthesis and Characterization of Phosphorous Containing NLO Polymers

Two diol monomers 2,6-Bis (4-hydroxybenzylidene)cyclohexanone (BHBC) and 2,6-Bis(4-hydroxy-3-methoxy benzylidene)cyclohexanone (BHMBC) were used as monomer for preparing phosphorus NLO containing polyesters. The monomers BHBC and BHMBC were prepared respectively by refluxing 4-hydroxybenzaldehyde and 3-methoxy-4-hydroxy benzaldehyde with cyclohexanone. The polyesters were synthesized by interfacial polycondensation of photosensitive diols with Phenyldichloro phosphate using hexadecyltrimethyl ammonium bromide (HDTMAB) as phase transfer catalyst. Copolymers were also prepared by incorporating Bisphenol-A in the polymer backbone. The synthesized monomers and polymers were characterized by UV-vis, FT-IR, 1H, 13C, 31P-NMR spectroscopic techniques. Thermal properties of the polymers were studied by thermogravimetric analysis and differential scanning Calorimetry under nitrogen atmosphere. The polymers show good SHG efficiency and thus it may be considered as a promising material for NLO application.