POLYFLUOROAROMATIC POLYIMIDE MATRICES FOR NONLINEAR OPTICAL POLYMER MATERIALS, NONLINEAR OPTICAL POLYMER MATERIALS AND METHODS FOR PRODUCTION THEREOF Russian patent published in 2020 - IPC C08G73/10 C08J5/18 G02F1/35 

FIELD: chemistry.

SUBSTANCE: invention relates to heat-resistant polyfluoroaromatic polyimide and copolyimide matrices, which are intended for nonlinear optical polymer materials, to a method of producing polyimide and copolyimide matrices, as well as to a method of producing nonlinear optical materials with high temperature and time stability of properties. Polyimide matrix has a glass transition temperature in range of 238–256 °C. Polyimide matrix has a glass transition temperature of 218–234 °C. Method of producing polyimide matrices consists in dissolving dianhydride monomer in an amide solvent. Equimolar amount of the polyfluoroaromatic diamine monomer is added to the obtained solution, the monomer solution is stirred in an inert atmosphere at 50–60 °C for 48–60 hours and a prepolymer solution is obtained. Thin layer of prepolymer is obtained by way of watering or centrifugation on a substrate. After that, prepolymer is cured by heating in stepwise mode of 80 °C/0.5 h, 170 °C/1 h, heating rate of 1 °C/min. Method of producing copolyimide matrices consists in dissolving 10 molar portions of dianhydride-monomer in an amide solvent. 7 molar parts of the polyfluoroaromatic diamine-monomer are added to the obtained solution; the monomer solution is stirred in an inert atmosphere at 50–60 °C for 48–60 hours. Thereafter, 3 molar portions of oxydianiline monomer are added and the obtained solution is held under the same conditions for 12 hours to obtain a prepolymer solution. Thin layer of prepolymer is then obtained by way of watering or centrifugation on a substrate. Prepolymer is then cured by heating in stepwise mode of 80 °C/0.5 h, 170 °C/1 h, heating rate of 1 °C/min. Method of producing nonlinear optical materials involves adding a solution of N-ethyl-N-(2-hydroxyethyl)-4-(4-nitrophenylazo)aniline to the above prepolymer solution in ratio 3:1 by weight. Obtained solution is then applied on a glass or silicon substrate by centrifugation at a rotation rate of 1200 rpm for 1–1.5 minutes. Layer is held on substrate at temperature of 50 °C for 12 hours. Then one performs hardening in external electric field at voltage 6–6.5 kV at discharge gap of 1 cm, current intensity of not more than 2 mcA, temperature and time mode of 80 °C/0.5 h, 170 °C/1 h, heating rate 1 °C/min, and cooled to room temperature in electric field.

EFFECT: invention enables to obtain electro-optical material based on polyimide and copolyimide matrices, having high nonlinear-optical characteristic (d₃₃) and temperature-time stability of nonlinear optical properties.

6 cl, 1 dwg, 2 tbl, 11 ex