Further Study On The Polycondensation And Characterization Of Polysulfonamide

Polysulfonamide （PSA） fiber, is a high temperature resistance fibre, has excellent heat resistance, thermal stability, dimensional stability, flame resistance and a series of excellent performance. However, compared with the congeneric products of fibers, the breaking force of PSA fiber is inadequate, so we study on the law of Polysulfonamide by the Method of Low-temperature Solution Polycondensation, prepare a series of different parameters of polymer resin, analyze its comparative molecular weight, thermal properties studied by using thermo gravimetric analysis （TGA）, rheological properties of the spinning solution, solidification performance, and ultimately gain a higher molecular weight, suitable for spinning dope preparation of the polymer.The conditions such as the reaction time, the reaction temperature, the dope concentration, the initial ratio of TPC/DDS on the molecular weight of PSA copolyamides were studied. A different initial ratio of 33DDS/DDS series （25mol%33DDS） were synthesized, The optimal reactivity condition is dope concentration of 13%, reaction temperatureof 10℃, the TPC/ DDS mole ratio of 1.001～1.003, the polymertizationtime of 50min～60min. Two kinds of high weight copolymer with different molecular structure were prepared:（1） controlled the feed order, To react to form a block copolymer of polysulfonamide ;（2） controlled the feed order and changed monomer, To react to form a block copolymer of modified-polysulfonamide.Study on the thermal performance and the thermal decomposition kinetics of polysulfonamide, we have obtained different parameters of the onset PSA polymer decomposition temperature, the inflection temperature, the termination point temperature, the residual Mass as wellas thermal decomposition kinetics parameters. It also showed that:33DDS content and polymer concentration are not affected on the thermal stability of copolymer resins. With the increase of 33DDS polymer content, the thermal stability of copolymer is fall slightly. The macromolecular conformation has significant impact on the thermal stability. The thermal stability of the block-copolymers and the block-modified copolymer are better than that of the mixed poly copolymer.Rheological properties, viscous activation energy, structural viscosity index of the different parameters of polysulfonamide were obtained by studies of rheology properties of the dopes for the subsequent spinning process.The dependences of coagulation value and critical concentration of the solvent （DMAc） on coagulant, coagulant concentration, temperature, concentration of CaCl₂ were investigated. It is shown that water was a kind of strong coagulant for its low coagulation value and that the coagulation value increased with the increase of coagulation concentration, CaCl₂ concentration and temperature.New ideas mainly brought forward in this paper are as follows: With the introduction of the new feeding methods, heavy polymer with multiple structures gets high molecular weight, so that its performance in heat-resistance is better than that of mixed heavy polymer, and it also helps the diversification of products.