Synthesis and properties of novel nonlinear optical polyester containing carbomethoxycyanovinylnitrocatecholic group

ABSTRACT

A new X-type polyester 5 containing 4-(2′-carbomethoxy-2′-cyano)vinyl-5-nitrocatecholic groups as nonlinear optical (NLO) chromophores, which are parts of the polymer backbone, was prepared and studied its properties. Polyester 5 is soluble in common organic solvents such as acetone and dimethylsulfoxide. Polymer 5 shows a thermal stability up to 280°C from thermogravimetric analysis with glass-transition temperature (T_g) obtained from differential scanning calorimetry of near 110°C. The second harmonic generation (SHG) coefficient (d₃₃) of poled polymer 5 film at the 1064 nm fundamental wavelength is 6.13 × 10⁻⁹ esu. The dipole alignment of polymer 5 exhibits a thermal stability up to T_g, and no significant SHG decay is observed below 110°C due to the partial main-chain character of polymer structure, which is acceptable for NLO device applications.

KEYWORDS:

• Differential scanning calorimetry (DSC)
• dipole alignment
• NLO
• polyester
• SHG coefficient
• thermogravimetric analysis (TGA)

Funding

This research was supported by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education (No. 2015R1D1A1A09058972).