Chemical properties of sodium borohydride
Strong reducing ability: Sodium borohydride is a medium-strength reducing agent with strong selective reducing ability. It can selectively reduce carbonyl and aldehyde groups to hydroxyl groups without reacting with carbon-carbon double bonds and triple bonds. For example, it can achieve the reduction of aldehyde and ketone carbonyl groups under very mild conditions to generate primary alcohols and secondary alcohols.
Reaction with water and alcohol: Sodium borohydride will react slowly with substances containing hydroxyl groups such as water and alcohol to release hydrogen, but the loss of sodium borohydride in a short time is very small, so sodium borohydride can be used as a solvent with alkaline solution, methanol, and ethanol.
Acid sensitivity: Sodium borohydride will quickly decompose and release hydrogen under acidic conditions, so it cannot react under acidic conditions.
Hygroscopicity: Sodium borohydride has strong hygroscopicity and is easy to absorb water and deliquesce.
Stability: Stable in dry air, decompose in wet air, and also decompose when heated at 500℃.
Specific applications of sodium borohydride
Sodium borohydride has a wide range of applications, including medicine, plastics, papermaking, fuels, and chemical synthesis. In the pharmaceutical industry, sodium borohydride is used as a hydrogenating agent for the manufacture of dihydrostreptomycin. In the plastics industry, it is used as a foaming agent; in the papermaking industry, sodium borohydride is used for bleaching wood pulp and clay. In addition, sodium borohydride can also be used as a rocket fuel additive, a foaming agent for making foam plastics, a bleaching agent for leather production and paper, and for removing heavy metals from sewage.