Structural characteristics of different sodium lignosulfonates (SLs)

Kinsperse126

Ultrazine Na

Borresperse Na

GZMN

and SXMN were investigated with ultraviolet spectrum

gel chromatography and chemical titration.The total hydrophilic groups content of Ultrazine Na was 5.46 mmol8226;g-1

which was the highest among these SLs.The sulfonic groups content of Kinsperse126 was 2.05 mmol8226;g-1

which was the highest among these SLs.The weight-mean relative molecular weight (Mw) of GZMN was 13000

which was the largest of these SLs.Mw of SXMN was 10000.Each SL was used as dispersant of dimethomorph water-dispersible granules (WG) respectively.The properties of dimethomorph WG were also investigated.The suspending rate of the WG with Kinsperse126 was as high as 95.03%.The suspending rate of the WG with SXMN was 89.70%.The dispersion ability of SL increased with increasing content of sulfonic groups and increasing Mw.Moreover

the sulfonic groups content was more important than Mw.Turbiscan LabExpert was initially used to estimate the stability of dimethomorph WG’s suspension.The suspension with Kinsperse126 had the best stability

in which deposition did not appear until 15 min and the height of sediment was only 0.38 mm.Particle size increase in the WG’s suspension with GZMN was only 0.59 μm which was the lowest.The stability depended on the dispersion ability of SL; furthermore

a larger Mw could weaken particle size increase.