Finings Co. Ltd.

Shanghai Fanglun New Material Technology Co., Ltd.

Guoqiang Wen

Nongyue Wang

Quanzhong Zhao

Jianming Shao

Guohua Li

Xiongwei Qu

Disclosed herein is a method for aramid polymerization using carbon dioxide as a solvent, comprising reacting phenylenediamine with benzenedicarbonyl dichloride, wherein an acid-binding agent is added to the reaction system, and liquid carbon dioxide and/or a supercritical carbon dioxide fluid is used as a reaction solvent. The method of the present application is environmentally friendly, saves resources, has low cost, and is safe for production and suitable for industrial production. The polycondensate obtained in the present application has a controllable molecular weight, a good product quality, and an intrinsic viscosity ηinh of 8-9 dl/g. The yield in the aramid condensation stage can reach 98%, and the recovery rate of the aramid condensation solvent is higher than 90%.

Aramid polymerization method using carbon dioxide as solvent

A method for preparing chlorine gas through catalytic oxidation of hydrogen chloride is carried out by one-time hydrogen chloride feeding and multi-stage oxygen feeding, one-time oxygen feeding and multi-stage hydrogen chloride feeding, or both, returning a product gas stream without separation thereof, and optionally carrying out heat insulation means. In the present invention, excessive reaction heat concentration is prevented, therefore, the method of the present invention is a chlorine gas recovery method implemented through the Deacon catalytic oxidation of hydrogen chloride that may be industrialized.

Method for preparing chlorine gas through catalytic oxidation of hydrogen chloride

Clean process for preparing a chloroformyl-substituted benzene by oxidation of a tail gas hydrogen chloride from a chlorination reaction and a chloroacylation reaction and recycling of the resulting oxidation product chlorine gas into the chlorination reaction. The present invention provides a clean process for preparing a polymer-grade chloroformyl-substituted benzene.

Clean process for preparing chloroformyl-substituted benzene

The present application relates to a method for photochlorination, and specifically to photochlorination by a photochemical reaction of an aromatic compound with gaseous chlorine so as to prepare a trichloromethyl-substituted benzene, and to a method using bis-(trichloromethyl)-benzene as the trichloromethyl-substituted benzene to prepare by further reaction bis-(chloroformyl)-benzene. Through the control of temperature, illuminance and consumption of gaseous chlorine, the method of this application can greatly improve the purity of trichloromethyl-substituted benzene and further prepare polymer-grade bis-(chloroformyl)-benzene with low cost. The present application also relates to a method for purifying trichloromethyl-substituted benzene, and specifically to a method for purifying trichloromethyl-substituted benzene via molecular distillation. The present application further relates to a photochlorination reactor for use in photochlorination reactions (such as those of the present application).

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Shanghai, China

Guoqiang Wen