Alkyl polysaccharides (APS) alkyl polyglycosides (APG) are non-ionic surfactants obtained by reacting natural or renewable raw materials such as glucose in starch with fatty alcohols. This surfactant has the advantages of low toxicity to aquatic organisms, raw materials derived from biological sources, easy biodegradation, non-toxic to crops and good compatibility with the environment; it also has low irritation to the human body, fast biodegradation, Excellent performance, synergistic effect with other surfactants, etc. This type of surfactant is not like the commonly used nonionic surfactants and does not rely on polyoxyethylene. It can change the HLB value by changing the alkyl lipophilic group chain length and reduce the solubility in water as the chain length is increased. Become a new generation of green surfactants.
In the 1990s, the Henkel company in Germany used it in pesticides, such as the brand name AgrimalPG for new glyphosate formulations, and it has been used in Europe, the United States and other countries and regions. There are also many domestic companies producing APG, and some glyphosate are used as research objects and applications in glyphosate (such as isopropylammonium salt, ammonium salt, and even potassium salt) in preparation manufacturers.
When some researchers used APG to study the synergistic effect of glyphosate, the results showed that APG has high surface activity in aqueous solution, and the surface tension and contact angle of aqueous droplets on plant leaves are small; -200, APG-810A, APG-810B measured surface tensions were 28.53, 28.20, 29.40mN/m, and their contact angles were 28.80, 19.70, 24.77 (○), indicating that APG has strong wettability. The surface tension can be reduced when used in the glyphosate water agent. The 41% glyphosate isopropylamine salt solution is added to the sample of APG-200 and diluted to 0.10%, and the surface tension of the water agent can be reduced to 33.23mN/m; while using tallow amine The surface tension of 41% Roundup water agent of additives is 39.90mN/m), obviously the wettability of using APG additives is better than that of tallow amine additives. However, although the reduction of surface tension helps to improve the efficacy, it is not the only decisive factor to improve the efficacy.
The synergistic effect of APG on glyphosate may be the result of multiple factors. The effect of reducing surface tension and contact angle plays a wetting effect; good wettability makes the agent easy to spread, increasing the effectiveness of droplets and targets The covering effect is conducive to the absorption of the medicine. The glyphosate medicament added with APG has obvious swelling effect on the leaf surface, indicating that APG can dissolve, swell or destroy the waxy layer of plant epidermis, promote the penetration of the medicament, and is beneficial to absorption. In addition, APG is a non-ionic surfactant, and most of its solubilized substances are in the outer shell of the fence layer. The volume of the solubilization area is larger, so the solubilization amount is larger, and it is easier to dissolve the waxy layer of the leaf epidermis; at the same time, it can prevent or delay the formation The crystalline droplets prolong the absorption time of the medicine and help improve the efficacy of the medicine.
The ability of APG to reduce surface tension is stronger than that of tallow amine polyoxyethylene additives, but its dissolution and swelling, and promote the penetration of the drug is not too strong compared with tallow amine polyoxyethylene additives; because of tallow amine Polyoxyethylene additives can not only dissolve and swell the waxy layer of the epidermis, but also can diffuse and penetrate into the underlying tissues, causing the cell wall and plasma membrane to absorb glyphosate, so its synergistic effect is stronger. In addition, they are also prone to foam when packaging, so they can only seize the low-end glyphosate market. If APG is mixed with tallow amine polyoxyethylene surfactants, better results will be obtained and safety will also be improved.