Synthesis And Characterization Of Super-absorbent Polymer

Super-absorbent polymer (SAP) can absorb a large amount of water compared with general water-absorbing materials, in which the absorbed water is hardly removable ever under some pressure. At present,as a new important functional material, so it had ever been honored as one of the new technique in Japan 1990s. At present, the method of SAP synthesis in aqueous solution is comparatively applicable .This method includes the following typical procedure. A homogeneous solution is formed by the monomers (such as Acrylic acid, Acrylamide, Aerylonltrile), sodium hydroxide or potassium hydroxide, the the crosslinking agent including polycol and N,N'-methylane-bis-acrylamide and water, then the solution is polymized by addings initiator. The production is heated and dried, during which crosslinking between moleculars is carried through at the same time, producing the water absorbent polymer that is well-preparetioned in crosslinking. The SAP synthesis in aqueous solution have several advantage including lower system viscosity, easy temperature controlling, slight superheat in location and simple procedure, etc. The initiator or catalyst which disperse equal easily is wrapped by polymer difficultily, and it owns the higher iniating efficient. The production owns uniformitied molecular weight could be made into film, powder and fiber, etc. The anomaly powder production is used widely and higher absorbent rate. Therefore there has become the focus that how to optimize the manufacture technics and adjust the factors that influence the capabilities of SAP as the low concentration of the monomers, slow polymerization rate, the untilizing ratio of equipment and manufacture throughput, and the low production molecular weight at the same time. The aqueous solution polymerization is used and the merits of the method are inherited in this study. The samples SAP own excellent capabilities with the graft polymerization through introducing the natural polymer monomers and preparing polymer monomers such as acrylic acid and acrylamide. In this article, we reported on bentonite composite super-absorbent polymers of bentonite and acrylamide. Based on materials bentonite and acrylamide and the crosslinking agent of N,N'-methylene-bis-acrylamide(MBA) was prepared by water solution copolymerization and with ammonium persulfate/sodium sulfite as redox initiator. The synthetic variables (the cross-linker amount, initiator concentration and the bentonite amount ) were also studied. The water absorbency (WA) is increases with increases of the cross-linker, initiator and bentonite amount and decreases slowly with further increase in the amount of the materials. It was found that the intensity of the partially hydrolysed crosslinked polyacrylamide containing bentonite after absorbing water is many times larger water is than that of one without bentonite. The optimal reaction conditions were 80℃, 6h reaction-and-drying time, 20% bentonite, 0.0017% crosslinker and 0.17% initiator on the three of the mass of acrylamide used. Using potassium persulfate and N,N'-methylene-bis-acrylamide as an initiator and...