Oil and Grease Additives

Apr 11, 2022

Pesticide adjuvant is the general term for various adjuvants used in chemical pesticide processing formulations in addition to active ingredients. The adjuvant itself has no biological activity, but has a synergistic effect. It can improve the efficacy, reduce the amount of pesticides, save costs, and reduce the pollution of pesticides to the environment. The synergistic effect of adjuvants on pesticides, especially herbicides, is mainly achieved by increasing the amount of pesticides on the plant surface, extending the residence time and improving the ability to penetrate the plant epidermis. Due to the different types of additives, their mechanism of action is also different. In use, surfactants such as emulsifiers and extenders are more widely used and have a greater impact on the performance of the medicament.

Application of additives
The addition of surfactant greatly reduces the surface tension of the solution, enhances the wetting spread and adhesion of the agent on the surface of the plant or pest, thereby improving the efficacy of the drug. The pesticide surfactants currently used mainly include: fatty alcohol polyoxyethylene type alkyl phenol polyoxyethylene ether type, sulfonate type, sulfonate type amide type, organic silicon type and so on. When DC-X2-5394 and methylated sunflower oil are used together with chlorimuron-methyl, dicamba and bentazone, the efficacy of dichroic milo and setaria is improved. Diformamide Silwet L-77, which is used to control apple tree black spot disease (including leaf rollers and scale insects), can reduce the amount of active ingredients by 50% under the same control effect, and the residual amount on the fruit is also reduced accordingly. In the field efficacy test, 750 times the Jinggangmycin solution (adding 0.04% APSA-80) was used. Within 14 days (days) after the drug, the control effect was the same as 500 times single use, but to 21 days (days) Time control effect is significantly higher than 500 times single use.

In recent years, the development of biosurfactants has made rapid progress and has a promising future. Such as multifunctional plant synergists, which contain a variety of alkaloids, glycosides, tannins, etc., which can interact with acidic organochlorines, organophosphates (except dichlorvos), organosulfurs, heterocyclics, chloroformates and pyrethroids Mixed use of similar pesticides can improve the effect of pesticide use. Tea saponin is widely used as a wetting agent and suspending agent in wettable powder pesticides. There are also many studies on other natural surfactants such as vegetable oil and seed kernel powder.

Oil and grease additives
Oil additives can speed up the absorption efficiency of pesticides sprayed on leaves by crops. They can form a uniform and stable emulsion with pesticides, water, etc., and help target crops to absorb pesticides when sprayed on leaves. Commercial petroleum lubricant additives and emulsifiers have been applied to Pursit's control of 3 kinds of weeds. The wax on the surface of the target crop can be dissolved in the petroleum lubricant solution, and its solubility varies with the type of crop and the growth environment. Different but different.

Vegetable oil additives are much better than petroleum lubricants and non-ionic surfactants in enhancing the biological activity of herbicides and reducing droplet drift. For example, the mixing of enoxypyr and methylated oil additives Scoil has a better effect on the control of three weeds than the petroleum lubricant additives CleanCrop. Vegetable oil additives can promote absorption and conduction and enhance the herbicide's control effect on weeds. Tests have shown that plant fatty acids and fatty acids are stronger than glycerides. Chester L. Foy and others pointed out that in increasing the herbicide nicosulfuron on the control effect of setaria, methylated sunflower oil, petroleum lubricating oil, non-ionic surfactant WK, non-Guo type surfactant X-77 Decrease in turn.

Inorganic salts
The combination of some inorganic salt additives and surfactants can greatly improve the activity of herbicides. These inorganic salts include ammonium sulfate [(NH4)2SO4], diammonium hydrogen phosphate [(NH4)2HPO4], sodium sulfate [Na2SO4], sulfuric acid Manganese [MnSO4]. However, some salt sprays have an antagonistic effect on some herbicides. The data shows that in calcium, magnesium, sodium, potassium, and iron salts, in addition to calcium sulfate [CaSO4], sodium sulfate [Na2SO4], calcium phosphate [Ca3(PO4)2], sodium phosphate [Na3PO4], they all have 2,4-D Produce antagonism, but this antagonism can be reduced by lowering the pH value of the solution or converting 2,4-D into difficult-to-dissociate salts. Urea, ammonium nitrate, ammonium polyphosphate, ammonium sulfate, petroleum lubricating oil and non-ionic surfactants are used to control the caesarean in cereal crops when mixed with gazodipine and enoxydine. Petroleum lubricating oil is larger than surfactants or salts.

Mixed use of various additives
In practical applications, in order to improve the efficacy of drugs, multiple additives can be selected at the same time, but the interaction between the various additives must be paid attention to and reasonable configuration. In the same dosage form, different types of additives will obviously affect the performance of the medicament. Unsuitable wetting agents and dispersants will reduce the suspension rate of the wettable powder. Surfactants will also affect the foliar absorption of the medicament. It is especially important in stem and leaf treatment pesticides.

Penetration of compound solutes
The penetration rate of the compound is not only related to the solubility in the epidermis/wax, but also related to the evaporation rate of the solvent. After evaporation, the permeation rate of the compound will be affected by the concentration in the horny wax layer and epidermis. Surfactants may have the effect of dredging the transport barriers, hindering the dispersion of compounds, transferring the sites of absorption, changing the properties of compounds, reducing their resistance, and creating conditions for plants to inhale active compounds.