The concept of food silicone is very vague, and there is currently no mature industry standard to define what is silicone food. According to the current popular explanation on the Internet, food silica gel consists of two parts: one is an inorganic silica gel with a main component of SiO2·nH2O, and the other is a synthetic silicone rubber. With our current understanding, food silicones are silicones that are related to food applications in organic silicones and synthetic silicones. Food silicone needs to meet various food safety standards.
The inorganic silica gel whose main component is SiO2nH2O is an inorganic polymer colloidal material obtained by polycondensation of silicic acid. The content of SiO2·nH2O is above 98%, non-toxic and odorless, and the chemical properties are stable. It does not react with any acid-base salt except for caustic and hydrofluoric acid under normal conditions. Because it is a colloidal structure, it has many micropores and a large specific surface area. The silica has a pore diameter of about 8-10 nm, a specific surface area of 300-500 m2/g, and the surface is hydrophilic, and has a strong absorption ability for water, and its water absorption capacity can reach 80%-100% of its own weight under high humidity conditions. . Therefore, the silica gel can be used as an external desiccant for foods and pharmaceuticals.
After the refined silica gel can be mixed with food and medicine according to the required amount, the dried food can be directly guaranteed to be eaten together with the food without any toxic or side effects on the human body. There is also a type of food silicone called food purification silica gel, the use of inorganic silica gel surface adsorption force to remove impurities in the liquid. Food silicone rubber is a part of synthetic silicone rubber that meets food safety standards.
This kind of silicone rubber is a kind of synthetic rubber, which is a linear polymer elastomer polymerized from dimethylsiloxane and other organic silicon monomers, referred to as SIR. The main chain of macromolecules is mainly Si-O units, and the monovalent organic group is a pendant group. The general structural formula is shown in the figure. In the formula, R, R′ and R′′ are organic groups, such as methyl, vinyl, and phenyl groups. , trifluoropropyl, etc., in the actual operation process, R, R', R" to consider the biological inertness of the group, to ensure that meet certain parameters, harmless to the human body. m and n are polymerization degrees and are integers that vary over a wide range.
The excellent performance of food silicone rubber is easy to use. It is mainly used for complex moulding of foods, making various food-related appliances, making medical appliances and food-related transport packaging.