低苯酚和甲醛残留氨基磺酸系高效减水剂合成工艺

研究了低苯酚和甲醛残留的氨基磺酸系高效减水剂(ASP)的合成工艺,通过IR和GPC研究了其结构、分子量及分布。结果表明:反应物配比、时间、pH值及温度等工艺参数影响产品的分散性能及残留苯酚和甲醛质量分数。氨基磺酸系高效减水剂的优化合成工艺条件为:n(对氨基苯磺酸钠)∶n(苯酚)∶n(甲醛)=(0.75—1.0)∶1∶(2.5—5.0),溶液pH值为8.5—11.4,反应时间2.0—3.5 h,反应温度为80—95℃。在此条件下合成的ASP中残留苯酚和甲醛质量分数远低于树脂类产品的国家标准。

Synthetic technology of aminosulfonic acid-based superplasticizer with low residual quantity of phenol and formaldehyde

The synthetic technology of aminosulfonic acid-based superplasticizer with low residual quantity of free phenol and formaldehyde was studied,and its structure,relative molecular mass and its distribution were also studied with IR and GPC.The results indicate that factors such as reactants ratio,time,temperature and pH affect the(dispersing) performance and the contents of free phenol and formaldehyde in ASP.The optimum synthetic conditions are as follows: the molar ratio of sodium sulfanilate,phenol and formaldehyde is(0.75-1.0) ∶ 1 ∶(2.5-5.0);the time is 2.0-3.5 h,and temperature is 80-95 ℃,and the pH value of solution is 8.5-11.4.The residual quantity of phenol and formaldehyde in ASP produced under the optimum conditions are far below the national standard of resin products.