Synthesis And Properties Of Naphthalenesulfonate Promoters

Naphthalenesulfonate dispersant is an important and commonly used pesticides dispersant, because of its good dispersion, water-soluble, anti-hard water, become an important pesticide dispersant.α-methyl naphthalene sulfonic formaldehyde condensate was synthesized from methyl naphthalene by four steps:firstly,sulfonated by H2SO4,then hydrolysised by H2 O,nextly condensated by HCHO and neutralized by Na OH.The factors influencing of the dispersion ability were investigated. The best sulphonated reaction conditions were described as below: the mole ratio of material is n(methylnaphthalene): n(H2SO4)= 1:1.2; sulfonation temperature was 155℃, sulfonation time was 4h,in this condition, the sulfonated rate reached 93.8%,the best hydrolysis temperature and hydrolysis time were 120℃,40 min.finally,Synthesized different polymerization degrees methyl naphthalene sulfonate formaldehyde condensate by Controlling the amount of formaldehyde. The structures of dispersant were characterized by infrared spectroscopy,ESI-MS and nuclear magnetic resonance(NMR).Apply effects and surface performance differences of dispersants were studied By measuring the critical micelle concentration(CMC),Γmax,Amin,PC20。The results showed that the degree of polymerization is about equal to 5,the critical micelle concentration is minimal,CMC value is 4.7mmol/L,γcmc=44.90 m N/m.The application of dispersants was explored in water dispersible granules(WDG) such as 80% Dimethomorph WDG, 75% Tribenuron WDG, 75% Atrazine WDG and so on. The study showed that when dosage of the dispersants was4%~5%,Suspension rate were highest, suspension particle size distribution in the 2.2 ~ 6μm. Compared with Morwet-D425, the obtained WDG with our dispersants has the better properties, such as dispersion, anti-hard water and heat storage capacity. This kind of dispersant must have very well potential applications in the pesticides field.