木质素磺酸钠的超滤级分对质量分数40%腈菌唑WP性能的影响

通过超滤将石岘木质素磺酸钠(简称木钠)分成5个相对分子质量(以下简称分子量)范围的级分。凝胶色谱和电位滴定测试表明,随着截留分子量由小变大,木钠超滤级分相对分子质量依次增大,重均分子量从2360增加到19852;磺化度依次减小,从2.66mmol/g降低到0.98mmol/g。以木钠超滤的5个级分为分散剂制备质量分数为40%的腈菌唑可湿性粉剂(WP)并测试其性能。结果表明,Fraction4(30000～50000)作分散剂制备的WP性能最优,热贮前后的悬浮率分别为85.36%和81.38%,悬浮液中分散相的平均粒径分别为6.30μm和9.19μm,热贮后WP悬浮液2h的沉淀层厚度及分散稳定指数分别为0.311mm和3.85。

Effect of Sodium Lignosulfonate′s Ultrafiltration Fractions on 40% Myclobutanil WP′s Performance

Using the ultrafiltration method to divide Shixian sodium lignosulfonate(LS) into five molecular weight range fractions.The gel permeation chromatography and potentiometric titration testing shows the relative molecular weight of LS is increased with the fraction,from 2 360 to 19 852.The sulfonic acid content of LS is decreased with the fraction,from 2.66 mmol/g to 0.98 mmol/g.Using the five fractions' LS as dispersants to prepare 40% myclobutanil WP's and test their performances.The results shows that WP's performances are the best when using the LS of fraction 4(30 000～50 000) as dispersant.The suspension rate before and after heat storage are 85.36% and 81.38%.The average particle sizes of the WP suspension's disperse phase are 6.30 μm and 9.19 μm respectively,and the 2 h suspension sedimentation layer thickness and the stability index of WP(after accelerated aging) are 0.311 mm and 3.85.