Study On Synthesis Of Novel Polyamides With Hydrophilic Structure

With the rapid development of eco-friendly materials and human environment protection consciousness increasing, polymer materials should be high performance and renewable. Polyamide is one of the most widely used engineering plastics, however, the application in some areas must be limited for their poor solubility and dispersion in the water. So, the study on synthesis and polymerization process of water-soluble polyamide has significant actual meaning.In this study, we synthesized three novel water-soluble copolyamides containing sulfonate for the first time in the country, of which the reactant ratio is0.4:1,0.6:1and1:1respectively, by solution-melt polycondensation.The water-solubility of copolyamide with reactant ratio0.6:1is the best. The structures of polymerization products are ascertained by their spectrum of FTIR, RAM,1H-NMR and13C-NMR. The results show these products are anticipated polyamides.The cystal forms of synthesized polyamides were determined by wide-angle X-ray diffraction (WXAD).The thermal properties of the polyamides were investigated by means of different sanning calorimetry (DSC) and thermogravimetry analysis (TGA).The results indicate the melting points of the water-soluble copolyamides are lower than that of PA66,however, thermal stability better than that of PA66. It has been proved that the synthesized copolyamides are "really" water-soluble by means of UV spectrophotomete (UV) and dynamic light scattering (DLS). And the study of the real time FTIR spectroscopy of COPA (0.6:1) shows that the hydrogen bonds in polyamides becomes weak during the Brill transition. The methylene segment between the amide groups becomes moblie. These may be the essence of the Brill transition of the synthesized polyamide. The TEM pictures of the copolyamide aqueous solution show that the polyamide nanoparticles have piled up. There are voids among particles and mesopores inside particles. Atomic force microscopy (AFM) and transmission electron microscopy (TEM) were applied to the morphology of the water-solube copolyamide membranes.The results reveal that the membranes are nanoporous membranes,and the aperture were all less than50nm.