| Polyaspartic acid (PASP), biodegradable and environment friendly, is a kind of green chemicals of demand increasing globally. The synthesis and application of PASP is popular in other countries because the problem of environment has been paid more and more attention. The field of PASP application is not same with different molecular weight range. As a scale inhibition agent, it use in recycle cooling water system, boil-water and gas-oil water treatment. As a reducing- viscosity agent, it use in drilling fluid treatment. Plant growth is promoted and yield increased as a fertilizer synergia agent PASP applied. The water-absorbing polymer is prepared by PASP. Recently the research on the application of scale inhibition about PASP is reported frequently, but in other fields less work has been done in China. Based on the synthesis and kinetics research, the application on scale inhibition, viscosity reduction, fertilizer synergia and water-absorbing polymer preparation is done in this paper.There exist two raw materials for.PASP synthsis, one being the L-aspartic acid and the other being maleic anhydride. The way has an advantage in production cost by maleic anhydride polymerization but PASP molecular weight is low. The other way has some advantages such as simple process, no pollution, no by-product except small steam by thermal polycondensation with L-aspartic acid and has wide range of molecular weight from 1000-140000 with different reaction condition under catalysis or not. The polymer structure is characterized with IR, NMR and is proved to be PASP. The suitable reaction temperature and time are 220℃～240℃ and 3-4 h at no catalyst in the fields of scale inhibition and fertilizer synergia. The molecular weight of PASP is high in the fields of reducing-viscosity and superabsorbent polymer. It is prepared at reaction condition: 180℃, -0.088MPa, Asp:H3PO4=5:1 and the MW can be decided by the equation: MW=-7082+10110t according to reaction time t.The PASP synthesis is a process of step by step and liner polycondensation. The polycondensation kinetics of L-aspartic acid are determined under no catalysis at 200℃, 220℃,240℃, 250℃,260℃, the rate constant is 3.339×10-5,4.124×10-5, 6.643×10-4,1.231×10-3,2.603×10-3[kg2/(mol2·min)] respectively, the activation energy is 168.9kJ/mol and frequency factor is 2.032×1013kg2/(mol2· min). This is three-level reaction under no catalysis with L-aspartic acid or other raw materials thermal polycondensation, is showed by mechanism and experiment and the square of...
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