The Study on the Synthesis of the Starch Grafted Polyamidine
|School||China University of Petroleum|
|Keywords||Starch Graft polyamidine Synthesis Flocculation Performance|
The pure monomer polyamidine obtained there are small molecular weight, and the shortcomings of high cost, limited by the large degree of it in the application. Starch molecules with multiple hydroxyl groups, is easy to implement esterification, etherification, oxidation, crosslinking and grafting reaction, and starch graft copolymer in the polymer flocculant, the superabsorbent material, paper industry additives, oilfield chemical materials biodegradable with excellent performance in a wide range of practical applications, such as plastic film and plastic. Therefore, this project carried out the starch graft polyamidine method and cationic flocculants synthesized molecular weight, low cost. To a natural polyhydroxy polymer material - starch as raw material, and for the first time by alternately grafted acrylonitrile, the, double vinyl monomer, N-vinyl formamide preparation of starch graft polyamidine. This study used the aqueous solution graft polymerization generate intermediates the amidine directly in an acidic medium of the process, to optimize the reaction conditions, and specifically: (1) the intermediate graft polymerization conditions of: starch 11.1% (by weight ), double the amount of initiator of 0.440% (wt) monomer AN and NVF quality ratio 1:1, reaction temperature 50 ° C, reaction time 5h. (2) amidino conditions: The amount of hydrochloric acid 11.1% (by weight), a the amidino temperature of 95 ° C, amidino time of 1.5h. Soluble starch, graft the intermediates, graft polyamidine structure of composition characterized by FT-IR, respectively, the study and evaluation of the nature of the product - the charge density and intrinsic viscosity. The results show that the two monomers AN and NVF successfully grafted on starch successfully synthesized starch graft polyamidine; intrinsic viscosity of the obtained graft polyamidine 1.94dL · g-1, a charge density of 2.29 mmol · g-1. Flocculation performance of the product evaluation - research on the treatment of municipal sewage graft the polyamidine added 25.0 mg L-1 pm, the sewage treatment turbidity 4.2NTU; oil extraction containing polyethylene sewage oil-water separator, the graft polyamidine added capacity 50.0mg · L-1, the oil content is reduced from the original 1043.16mg · L-1 to 20.0mg · L-1, showed excellent treatment effect. Also do a single initiator graft polymerization, try to seed polymerization and other polymerization methods, achieved a certain effect. In this study based on the impact of the starch graft copolymer change initiator, starch, and the monomer concentration in the reaction on the graft efficiency and graft copolymerization reaction rate, determine the rate of graft reaction and the apparent activation energy. From information currently accessible starch graft polyamidine study in the country and outside are not been reported, there is an important innovation. However, the guanylating under acidic conditions, so there is the problem of the hydrolysis of starch, a low yield. Due to limitations of the experimental time is temporarily unable to find a better solution, later to be further studied.