Modified Aspartic Acid Heat-shrinkable Polymer Technology

Endangers caused by scale & corrosion inhibitor widely used at present are considered worse and worse. It is urgent to develop a new type envirenment-friendly inhibitor. As a biopolymer with scale & corrosion inhibition performance, polyaspartic acid (PASP) has become one of the reseach focuses because of its biodegradability in recent years. But problems go with the process of synthesization such as certain contaminative production cells, difficulty in controlling molecular weight, instability of product performance, high cost of the polymer and impossibility of Industrialization. To solve the above problems, PASP was synthesized using modified L-aspartic acid as raw material under the condition of high temperature for the first time. And the synthetical process and the product were integratively studied.Modification method was put forward in this paper. The reactant was evenly heated up under the conditions of churning up. The product quality, such as performance and chroma, was raised. Reaction time and temperature were affirmed as keys to synthesis experiment by different schemes. Influence of reaction conditions on conversion of polysuccinimide and molecular weight and that of molecular weight on scale inhibition of PASP were experimentally investigated. Results showed that the optimum masscie was about 3000.And the optimal reaction time & temperature was 2h and 230℃respectively.Considering PASP made by the above method as scale & corrosion inhibitor, a series of tests were set up. Contrastive examinations between PASP and polyacrylic acid (PAA) having eminent scale-inhibiting effect and wide application were made. Results showed that regardless of test condition, the scale-inhibiting performance of PASP was far stronger than PAA. The results of contrast reseach between PASP and HEDP showed that both had the same corrosion inhibition and PASP was suited to long test time. The effects of water quality on corrosion-inhibiting performance of PASP were examined. It was concluded that the optimal pH fit for PASP was 5.5~6.5, the function of corrosion-inhibiting was postponed because of the presence of Ca2+and Fe2+ in water, impact of corrosion-inhibiting was increased with the increase of Ca2+ concentration. Influence of Fe2+ concentration on corrosion-inhibiting enhancement was insignificant. All these results help guarantee feasibility of the reseach project application in practice.Scale & corrosion inhibition mechanisms of PASP were briefly analyzed at the end of this thesis.