水煤浆添加剂萘磺酸甲醛缩合物合成条件的优化

Naphthalene sulfonic acid formaldehyde condensate (NSF) was synthesized using refined naphthalene, concentrated sulfuric acid and formaldehyde as raw materials through three reactions, namely sulfonation, hydrolysis and condensation, and the optimized conditions for each reaction were obtained. The results show that when the yield of 2 -naphthalene sulfonic acid (2 -NSA) is the highest, the optimized conditions for the sulfonation reaction are n(naphthalene):n(concentrated sulfuric acid) = 1:1.15, reaction temperature 160 °C, and reaction time 3 h; for the hydrolysis reaction, to minimize the residual amount of 1 -naphthalene sulfonic acid (1 -NSA), the optimized conditions are reaction temperature 115 °C, reaction time 60 min, and n(naphthalene):n(water) = 1:2.3, and at this time, the conversion rate of 1 -NSA hydrolysis is the highest; the optimized conditions for the condensation reaction are n(naphthalene):n(formaldehyde) = 1:1, acidity 30%, reaction temperature 105 °C, and reaction time 2 h, and under these conditions, all 2 -NSA is polymerized to form NSF. The infrared spectroscopy (FTIR) and high - performance liquid chromatography (HPLC) analyses of the product NSF show that NSF obtained under different conditions contains abundant aromatic ring, methylene and sulfonic acid group structures; the HPLC analysis shows that NSF has differences in sulfonation degree, molecular weight and the main structure of the molecule (linear structure / branched structure), and these differences lead to different properties of NSF in reducing slurry viscosity and improving slurry stability when it is used as a coal water slurry dispersant; the NSF obtained under the optimized conditions is superior to the commercially available naphthalene sulfonic acid formaldehyde condensate - based dispersant (NX - 1) in reducing slurry viscosity, but the two have comparable abilities to maintain slurry stability.

以精萘、浓硫酸和甲醛为原料,依次经过磺化、水解、缩合三个反应合成了萘磺酸甲醛缩合物(NSF),并获得了各反应的优化条件。结果表明:当2-萘磺酸(2-NSA)产率最大时,磺化反应的优化条件为n(萘)∶n(浓硫酸)=1∶1.15、反应温度160 ℃、反应时间3 h;水解反应要使1-萘磺酸(1-NSA)的残留量最低优化条件为反应温度115 ℃、反应时间60 min、n(萘)∶n(水)=1∶2.3,此时1-NSA水解的转化率最高;缩合反应的优化条件为n(萘)∶n(甲醛)=1∶1、酸度30%,反应温度105 ℃,反应时间2 h,在此条件下2-NSA全部聚合生成NSF。产物NSF的红外光谱(FTIR)和高效液相色谱(HPLC)分析表明,不同条件下获得的NSF都含有丰富的芳环、亚甲基和磺酸基结构;HPLC分析表明,NSF在磺化度、分子量大小和分子的主体结构(线性结构/枝状结构)方面存在差异,这种差异导致NSF在作为水煤浆分散剂时,对降低浆体黏度和提高浆体稳定性方面具有不同的性能;优化条件下得到的NSF在降低浆体黏度方面性能优于市售的萘磺酸甲醛缩合物系分散剂(NX-1),但二者对保持浆体稳定性的能力相当。