丙烯酸类共聚物分散剂的合成及其分散性能

Synthesis and Dispersive Properties of the Acrylic Acid-based Copolymer Dispersant

以丙烯酸(AA)、苯乙烯磺酸钠(SSS)和丙烯酸羟丙酯(HPA)为单体设计正交实验,经聚合反应得到AA-SSS-HPA共聚物分散剂,测定了各种分散剂的分子量及对BaSO4的悬浮率.选择分散效果最好的分散剂作为研究对象,考察了温度、pH值、盐浓度、分散剂用量对BaSO4分散效果的影响,测定了悬浮液的沉降速度、粘度和颗粒的表面吸附量,并对分散后的颗粒粒径分布进行了表征.结果表明,在20℃的中性体系中,分散剂用量为0.4000g时,BaSO4悬浮率可达99.18%,BaSO4颗粒粒径约为350nm,悬浮液静置60h后,上层清液体积仅占总体积的2%.

The copolymer dispersants were synthesized with acrylic acid, styrene sulfonic sodium and 3-hydroxypropyl acrylate as monomers through the orthogonal experiments. The molecular weights of dispersants were determined, and the best dispersant was chosen out based on the suspension rates of the granules. The influences of temperature, pH, NaCl concentration and dispersant concentration on the suspension rate of BaSO4 granules were studied with the best dispersant. Sedimentation speed of BaSO4 particles was determined as well as the dispersant adsorption. The adsorption increased with increasing copolymer concentration in a Langmuirian mode and reached a plateau at the concentration of 4 g/L. Size distribution of the particles was analyzed. The average particle size in the presence of the polymer was less than that in the absence of the polymer. Using synthesized dispersant, well-dispersed suspension of BaSO4 could be achieved. The suspension rate of BaSO4 granules was 99.18% with 0.4 g dispersant when pH and temperature were 7 and 20 ℃ respectively. At the same condition, the average diameter of BaSO4 particles was about 350 nm and the clear liquid volume above was only 2% after 6 h standing.