The-advantage-of-obsh-foaming-agents
OBSH blowing agent, chemically known as 4,4'-oxobiphenylsulfonylhydrazine, has the chemical formula C₁₂H₁₄N₄O₅S₂, and the sulfonylhydrazine group contained in the molecular structure is the key to its foaming effect. In appearance, the OBSH blowing agent appears as a white powder, giving a sense of purity. It has a melting point of 150 - 165°C and a density of about 1.52g/cm³, which is excellent in terms of thermal stability. In terms of solubility, it is slightly soluble in hot water and ethanol, but insoluble in cold water and in most organic solvents, a property that enables it to perform precisely in different production environments and material systems.
In terms of synthesis methods, there are two main common routes for OBSH blowing agents. One is the chlorosulfonation route, in which diphenyl ether is used as the starting material and reacted with chlorosulfonic acid to form 4,4'-oxo-diphenylsulfonyl chloride, which is then reacted with hydrazine hydrate to obtain 4,4'-oxo-diphenylsulfonyl hydrazide. In another approach, diphenyl ether is first sulfonated with concentrated sulfuric acid and then reacted with phosphorous trichloride to form 4,4'-oxydiphenylsulfonyl chloride, which is then reacted with hydrazine hydrate and ammonia to form the target product . Although these two synthesis paths are complex, it is the precise control of the reaction conditions that ensures the stable and high quality performance of the OBSH blowing agent.
