Many novice customers will have such doubts, should they choose polyether polyols or polyester polyols? Let's talk about their differences and characteristics today, so that customers can choose according to different needs.
The main differences between polyether polyols and polyester polyols are:
1. Raw materials and synthesis process
Polyether polyols: usually low molecular weight compounds containing active hydrogen (such as ethylene glycol, propylene glycol, etc.) are used as initiators. Under the action of a chemical agent, they are formed by ring-opening polymerization of epoxy compounds such as ethylene oxide (EO), propylene oxide (PO), and tetrahydrofuran (THF). For example, with glycerol as the initiator, polyether triols can be obtained by ring-opening polymerization of propylene oxide.
Polyester polyols: Generally, they are prepared by polycondensation reaction of dicarboxylic acids (such as adipic acid, phthalic anhydride, etc.) and diols (such as ethylene glycol, 1,4-butanediol, etc.). For example, adipic acid and ethylene glycol undergo polycondensation under certain conditions to generate polyethylene adipate polyol.
2. Molecular structure
Polyether polyol: The main chain of the molecule is connected by ether bonds (-0-) and has more ether bond structures. Its molecular chain is relatively flexible and has less steric hindrance.
Polyester polyol: The main chain of the molecule contains ester groups (-COO-). The presence of ester groups gives the molecular chain a certain polarity and rigidity.
3. Appearance and state
Polyether polyol: Generally a colorless or light yellow transparent viscous liquid with relatively low viscosity and good fluidity.
Polyester polyol: Usually a colorless to light yellow viscous liquid or a waxy solid. Its viscosity is generally higher than that of polyether polyol, especially polyester polyol with a larger molecular weight may be in a solid state at room temperature.