Aliphatic polyester polyol type polyurethane has high strength and wear resistance due to the presence of polar groups such as ester groups and amino groups within its molecules, resulting in strong cohesion and adhesion. Aliphatic (often referred to as adipic polyester) polyester diols are commonly used in the production of cast polyurethane elastomers, thermoplastic polyurethane elastomers, microporous polyurethane sole, PU leather resin, polyurethane adhesive, polyurethane ink and color paste, fabric coatings, etc. The polyester glycol obtained from adipic acid and 1,4-butanediol, 1,6-hexanediol or ethylene glycol is a waxy solid, resulting in a polyurethane elastomer with strong crystallinity, high initial adhesion, and high mechanical strength of the product; Polyester, such as PMA and PPA, prepared from side groups of diols, is liquid and soft at room temperature. It is used for inks, soft leather, etc. PMA has good hydrolysis resistance.
Polyurethane made from aromatic polyester has excellent hydrolysis resistance, heat resistance, and adhesion. Phthalic anhydride polyester polyol and aromatic polyester polyol prepared from waste polyester/waste PTA are generally used to manufacture rigid polyurethane foam. The flame retardancy of rigid foam based on high hydroxyl value aromatic polyester polyol is better than that based on polyether polyol. In polyurethane foam plastic industry, aromatic polyester polyols are often used to replace some or all polyether polyols in polyurethane foam plastic and polyisocyanate rigid foam plastic formulations. Adding some aromatic polyester polyols to the formula of refrigerator combination in winter can also improve the toughness and adhesion of foam. Phthalic anhydride polyester polyol is particularly suitable for polyisocyanurate (PIR) foam. The foam plastic contains a large number of benzene rings, which not only improves the heat resistance of the foam, but also improves the flame retardancy of the products. Aromatic polyester polyols are widely used at home and abroad to manufacture sandwich foam panels for construction and on-site spraying construction in the construction industry. In addition to the basic properties of polyether type rigid polyurethane foam, this rigid polyurethane foam containing polyester also has the advantages of fine foam, good toughness, excellent flame retardancy and low price. Polyester polyols contain a large amount of primary hydroxyl groups, have high activity, can be applied at low temperatures, and can also reduce the amount of catalyst used. The specific application fields in the hard foam industry include: hard foam board and sandwich board, heat insulation composite for refrigerators and freezers, heat insulation composite for water heaters, spraying hard foam, wood imitation, single component hard foam, ultra-low density packaging foam, hard microporous sole materials, etc.