Polyether Polyol Vs Polyester Polyol
|26.8.2020||Posted by njchm under Advertising & Marketing|
Polyester polyol, which are organic substances, are usually formed by condensation (or transesterification) of an organic dicarboxylic acid (anhydride or ester) with a polyol (including a diol) or by polymerization of a lactone with a polyol. The dibasic acid is phthalic acid or phthalic anhydride or an ester thereof, adipic acid, halogenated phthalic acid or the like. The polyhydric alcohol is ethylene glycol, propylene glycol, diethylene glycol, trimethylolpropane, pentaerythritol or the like. Different types of polyester polyols have different properties due to different types or different preparation processes. Several indicators that are important for polyester polyols are hydroxyl number, acid value, moisture, viscosity, molecular weight, density, and color. Characteristics and uses of polyester polyols: Polyester-based polyurethane contains a large number of polar groups such as ester groups and amino groups in the molecule, and has strong cohesive strength and adhesion, and has high strength and wear resistance.
Polyether polyol (referred to as polyether) is composed of an initiator (active hydrogen group-containing compound) and ethylene oxide (EO), propylene oxide (PO), butylene oxide (BO), etc. in the presence of a catalyst. It is obtained by polyaddition reaction. The largest yield of polyether is glycerol (glycerol) as the initiator and epoxide (usually PO and EO). Various general-purpose polyether polyol products are produced by changing the feeding mode of PO and EO (mixing plus or separately adding), the ratio of addition, the order of addition, and the like.
China’s licorice resources are abundant, with licorice containing 7% to 10% of licorice and about 5.5% to 9.0% of licorice. Licorice extract can be obtained by solvent leaching to obtain licorice extract, and further processing can produce glycyrrhizic acid.
Monoammonium glycyrrhizinate is a white crystalline powder with a special sweet taste. It has antibacterial, anti-inflammatory, anti-viral, anti-microbial, liver and liver protection, throat cleansing, anti-oxidation, inhibition of melanin, high sweetness, low heat energy and health care. It has a wide range of applications in the fields of medicine, cosmetics, and food.