Synthetic method for poly terephthalyl terephaldiamine polymer

Abstract

The present invention relates to the synthesis of polyterephthalyl phenyldiamine and belongs to the field of polymer material. The present invention synthesizes polyterephthalyl phenyldiamine polymer with p-phenyldiamine and paraththaolyl choride and through several reaction steps, and during the reaction, alkali matter is added continuously to produce hydrogen chloride to make the reaction mild and controllable to obtain high molecular weight polymer with narrow molecular weight distribution and high product homogeneity. The produced polymer may be used in many application fields.

Description

technical field [0001] The invention relates to a synthesis method of poly(p-phenylene terephthalamide) polymer, which belongs to the field of polymer materials. Background technique [0002] At present, the synthesis of poly-p-phenylene terephthalamide polymer mainly includes two processes: interfacial polycondensation and low-temperature solution polycondensation. [0003] Interfacial polycondensation is to dissolve p-phenylenediamine and terephthaloyl chloride in two immiscible solvents to prepare a solution of a certain concentration, and then quantitatively mix the two solutions under high-speed stirring, and then The interface is polymerized, and then the by-product hydrogen chloride is neutralized with an alkaline substance, and then the obtained poly-p-phenylene terephthalamide polymer is separated. This method requires a large investment in production equipment, a large amount of solvent recovery, and high requirements for the control accuracy of the production pro...

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Problems solved by technology

This method requires a large investment cost for production equipment, a large amount of solvent recovery, and high requirements for the control accuracy of the production process. It is difficult to achieve precise control of reaction conditions, resulting in high production and operation costs, production equipment and control system investment.

[0004] Low-temperature solution polycondensation is to polymerize p-phenylenediamine and terephthaloyl chloride in strong polar solvents such as dimethylacetamide and N-methylpyrrolidone under low temperature conditions. In USP3,884,881, hexamethylphosphorus The amide is used as a solvent, and the jet mixer is used for mixing materials, and the twin-screw reactor is used for continuous polycondensation of low-temperature solution. The solvent hexamethylphosphoramide in this method has carcinogenic effect, and the jet mixer is easy to block, which affects the continuity of production; Zhao 53-133,296 uses N-methylpyrrolidone as a solvent and calcium chloride as a co-solvent, and p-phenylenediamine, calcium chloride and N-methylpyrrolidone are prepared into solutions and slurries respectively, and are mixed with molten terephthalamide After the acid chloride is mixed inside the S-1 mixer, it enters into the twin-screw kneader for polycondensation. The amount of calcium chloride used in this method is as high as 40%, and the resulting resin has a large ash content, and the S-1 mixer is easy to block; in the domestic open patent 90105870.x, Self-cleaning twin-shaft mixer and twin-screw reactor are used for low-temperature solution polycondensation. The production equipment is relatively complicated, and the heat exchange area of ​​the screw reactor is small. It is difficult to dissipate a large amount of reaction heat in the reaction process in time, which may easily cause local temperature overshoot. High lead to the generation of gel, and the requirements for the accuracy of material addition and reaction condition control in the production process are also very high, and the precise control of the reaction process is difficult to achieve, resulting in high investment in production equipment and control systems

[0005] During the low-temperature solution polycondensation process, with the increase of the by-product hydrogen chloride content in the system, the apparent viscosity of the reaction system will increase abnormally, which will slow down the mass transfer and heat transfer speed of the polymerization reaction system, which is not conducive to the progress of the reaction and is difficult Obtain high molecular weight poly-p-phenylene terephthalamide polymers, and in the above prior art, only increase the concentration of poly-p-phenylene terephthalamide polymers by using special solvents, or select special equipment to strengthen the reaction The means of the mixing effect of the system makes the reaction proceed, but this will make the reaction too violent and difficult to control, and does not take into account the removal of the by-product hydrogen chloride that is not conducive to the normal progress of the reaction

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