Hyperbranched Polyester Polyol HBP-500

Unlike linear or star polymers where MW scales directly with solution viscosity, hyperbranched polyesters have a compact globular 3D architecture with no chain entanglement. HBP-500 at MW ~3500 with 16–32 terminal OH groups has solution viscosity of only 3000–8000 mPa·s—far lower than a linear polyester of equivalent MW. This enables formulation of UV or 2K PU coatings at 85–95% solids content, drastically reducing VOC. The exceptionally high hydroxyl value (480–520 mg KOH/g) means each HBP-500 molecule provides 16–32 crosslink points to the isocyanate or acrylate network, producing very high crosslink density cured films (Tg >120°C, pencil hardness >2H, MEK rub >300 cycles). Typical use level is 10–30 phr in PU formulations to reduce viscosity while boosting hardness.