Polycaprolactone polyols are a special class of polyester polyols preferred in polyurethane elastomer applications where high dynamic durability, broad temperature profiles, very good hydrolysis resistance, and exceptional elastomeric properties are required. Polyester polyols, as a class, are generally selected for urethane applications where high tensile strength and tear resistance, sliding abrasion resistance, flex fatigue resistance, oil, grease and solvent resistance, and high temperature and oxidative stability are needed.
When compared with adipate-based polyester polyols in polyurethane elastomers, caprolactone polyols demonstrate the following performance advantages:
Superior resistance to hydrolysis
Greater weatherability and UV stability
Better low temperature properties (low Tg) and high temperature performance
Enhanced abrasion resistance
Higher chemical resistance to oils, fuels, & solvents
Cut, chip, and tear strength
Processing advantages due to their low viscosities and low polydispersity
No prepolymer viscosity creep on storage
Formulators can further enhance these general property sets by the proper selection of the "initiator" diol (see below) used to produce the various grades of polycaprolactone polyols. Hence, the polycaprolactone polyols exhibit a great versatility in the targeted design of polyurethanes requiring demanding performance attributes and service life. In addition to the "initiator" type used, polycaprolactone polyols are offered in a wide range of molecular weights (300-4000), functionalities (diols, triols and tetraols), with low acidity values and polydispersity's (Molecular Weight Distribution).