| To explore different factors on the physical storage stability of the pesticide suspension concentrate, guide the choice of pesticide component, construct excellent pesticide suspension system, the physical storage stability of 40% buprofezin SC and 50% carbendazim SC were studied by the performance evaluation of several major novel dedicated wetting-dispersant with the research of processing technic and rheology property.The choice of wetting-dispersant was the major factor in affecting the suspension physical storage stability. Several wetting-dispersants were estimated by mensurating the major technical parameters of SC, Integrating flow point method and trial method with the choice of thicken agents. The results showed that, the performances of carboxylate surfactant were excellent in 40% buprofezin SC, especially used with alkane sulfonate WLNO UK. The surfactants of alkylphenol ethoxylates, alkane sulfonate and so on were sensitive to temperature in 50% carbendazim SC. Viscosity of the relative suspension increased in hot storage. In particular,the impact of surfactant was different in the same type of TC produced by different manufacturers.Comparing the effects of different vertical, horizontal sand mills and different particle size, material grinding mediums to suspension grinding efficiency and physical storage stability, the result showed that,the vertical sand mill AO6314 was more efficient than other two vertical sand mills. And the horizontal sand mill was more efficient than vertical sand mills. The grinding medium also had significant impact on grinding efficiency. The smaller beadings were more efficient than the larger, and there was no significant difference between beading and pickax bead, a heavy metal. The difference of processing technic affected the physical storage stability of SC, due to the different particle size created in suspension.The influence of different thicken agents and dispersants to 50% carbendazim SC was tested by rheometer. The results showed that, The molecular structure of different dispersants and the different synergistic reactions between dispersant and xanthan gum (XG) were the main reasons of the influence of the flows. The rheological models of SC with dispersant TERSPERSE? 4896 were pseudoplastic fluids, which didn't changed with XG. The rheological models of suspension with dispersant TERSPERSE? 2210 had great changes along with the storage, pseudoplastic fluid change into dilatant fluid especially with the synergistic reaction of XG. The suspension with dispersant SOPROPHOR SC had the same change, but this transform can be slow up or even restrained through adding appropriate quantity of XG or bentonite. The research had significance in rheological mechanism. By now, there isn't any report about dilatant fluid in pesticide suspension system, except pseudoplastic fluid.The pseudoplastic fluid studied in pesticide SC was about the pertinences between rheological parameters and the physical storage stability of formulation. We tested the pertinences and found that, in the same SC system, stability index St had a certain pertinence to physical storage stability. The St larger, the stability better. And the relative viscosity, casson yield value, relative yield value had no pertinence with physical storage stability. Base on the research, we put forwardτx(the critical value of pseudoplastic fluid changing into bingham fluid), and the result of the test showed that there was a positive correction betweenτx and physical storage stability of formulation.The pesticide suspension concentrate is a very complex system. there is considerable variability in the performance of different TC. In the research of pesticide SC, we should still filtrate correlative adjuvants and processing technic by lots of experiments. But the knowledge of physical storage stability of pesticide SC got in mechanism must be helpful to the development of pesticide SC in our country, combing with the adsorption research of dispersant in pesticide TC and the rheology.
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