| Super absorbent polymer (SAP) is a type of water swelling polymer. Because of the unique water absorption and water retention performance it has been widely used in fields of petroleum chemical industry, water treatment, agriculture, forestry and gardening, etc. Although there are many reports on synthesis and characterization of high water absorbing resin until now, however it has problem of low resin bibulous rate and poor salt resistance which greatly limits its application. In this paper, the bibulous rate of polymer resin, water absorption capability of product, and salt tolerance performance are investigated. The results show that the performance of polymer resin is improved. Besides, polymerization process is also studied. The research content is divided into the following several parts:1. Synthesis of high water absorption rate SAR:SAR is prepared with acrylic acid, acryl amide and sodium p-styrenesulfonate as comonomer, sodium carboxymethylcellulos e as graft substrate, with index of water absorption rate and water imbibition of produc t. Monomer neutralization degree, initiator, cross-linking agent, sodium carboxymethycell ulose content are studied by single factor analysis, the influence of styrene sulfonic aci d sodium content, reaction temperature and other process conditions on water absorbing resin bibulous are researched. Product of pure water absorption980g/g, salt water absor ption (0.9%NaCl)103g/g is achieved.2. Salt resistance SAR is synthesized with acrylic acid, acryl amide as monomer, sodium lignosulfonate as additives to improve salt resistance of the product. Using the single factor analysis of neutralization degree, initiator, crosslinking agent, sodium lignin sulfonate, reaction temperature and monomer ratio on the process conditions, synthesis of the pure water absorption of1282g/g and salt water absorption of143g/g of salt resistance make high injectivity resin bibulous rate fast. On the basis of single factor experiment, adopting L25(55) orthogonal experiment to optimize the preparation process, the optimal preparation conditions as follows:the quality of the monomer AA/AM ratio3:1, dosage of sodium lignin sulfonate monomer is1.0%of the total mass, dosage of initiator is1.5%of the total dosage, crosslinking agent is0.05%of the total monomer mass, neutralization degree is50%, the temperature is90℃; absorbing ratio of distilled water absorption of obtained composite high absorbent resin with the method of above optimal proportion is1215g/g and salt water is125g/g.3. Structure, surface morphology and thermal properties of product are characterized using infrared (FTIR), scanning electron microscopy (SEM), thermogravimetric (TG-DTA) and other methods.4. In addition, water retention, water absorption rate, resistance to electrolyte of pr oduct are researched, the results show that acrylic acid series high water absorbing resi n not only has high water absorption and water retention, but also has better salt resist ance.5. In this thesis, the prepared high absorbent resin is applicated in cement product s, its curing performance and water retention performance in cement are observed, the effect of the maintenance of obtained resin is excellent. Compared with the blank samp le in air curing, its mechanical strength has been greatly improved, cement compressive flexural strength increased by21.8%and29.7%respectively, the prepared composite hi gh absorbent resin has broad application prospect. |
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