The main raw materials for polyether polyols include:
1. Oxidized olefin: The most commonly used are propylene oxide (PO), ethylene oxide (EO) and the less common epoxy butane (BO). These oxidized alkenes are combined with the initiator through ring-opening polymerization to form a polyether chain.
2. Initiator: also known as initiator or nuclear molecule, is a class of compounds containing polyols or amine groups, such as glycerol, propylene glycol, ethylenediamine, trimethylol propane, etc. The selection of initiator determines the molecular weight, functional degree and specific chemical structure of polyether polyols.
3. Catalyst: In the synthesis process of polyether polyols, catalysts are needed to promote the reaction between the oxidized olefin and the initiator. Common catalysts include alkali metal hydroxides (such as potassium hydroxide, sodium hydroxide) and organic amines.
4. Organic oxides and cyclic compounds: In the production of certain types of polyether polyols, cyclic compounds such as tetrahydrofuran may be used as one of the raw materials to introduce specific functionality or improve certain properties.
These raw materials are polymerized under appropriate conditions, and polyether polyols with specific properties can be obtained by precisely controlling the reaction conditions and proportions to meet the needs of different application fields.