Preparation of structurally-colored aromatic polyamides and their physicochemical properties

Conclusions One-, two-, and three-stage methods of preparing structurally-dyed aromatic polyamides with chromophoric fragments in the chain have been investigated.It has been shown that the molecular weight of the polymers obtained and the proportion of chromophores bound into their chain is determined by the reactivity of the starting diaminoanthraquinones.It has been found that the introduction of anthraquinone units into the poly-m-phenylene isophthalamide chain has little effect on the structure or basic physicochemical properties of the polyamide, but gives the polymer a uniform and regular coloration.Structural dyeing of poly-m-phenylene isophthalamide with fragments of 1,5-DAAQ or 4,8-DADHAQ increases the resistance of the polyamide fibres to UV irradiation.The authors express their thanks to Yu. Ya. Shavarin and N. M. Bol'bit for performance of the fibre irradiation, and also to B. A. Tsaplin for thermomechanical testing of the fibres.L. Ya. Karpov NIFKhI, Moscow. VNIISV, Tver'. Translated from Khimicheskie Volokna, No. 2, pp. 24–27, March–April, 1992.     

Ignition of a fuel-air mixture with a high-speed plasma jet

The conditions of ignition and the velocities of propagation of a flame along a tube in combustible mixtures prepared in advance upon ignition with a spark and a high-speed pulsed plasma jet are experimentally investigated.Chuvash State University, Cheboksary, Russia. Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 67, Nos. 5–6, pp. 424–427, November–December, 1994.     

Mechanism and kinetics of the low-temperature polycondensation of aromatic diamines with aromatic diacid chlorides

Conclusions A crossed correlation equation has been obtained, based on a study of the kinetics of model reactions of aromatic amines with aromatic acid chlorides in dimethylacetamide, which permits one to calculate the rate constants of the elementary stages in the process of aromatic polyamide synthesis.Using this equation, the rate constants have been calculated for reactions involved in the preparation of poly-m-phenyleneisophthalamide, poly-p-phenyleneterephthalamide, and polybenzamide. Some kinetic principles in the synthesis of these aromatic polyamides have been established.Translated from Khimicheski Volokna, No. 1, pp. 16–18, January–February, 1986.