Abstract: Hyperbranched polyurethane(HPU) was synthesized from toluene-2,4-diisocyanate(TDI) and diethanolamine(DEOA) by one-step method, which was further modified to prepare UV-curable hyperbranched polyurethane(UV-HPU) and hyperbranched hybrid polyurethane(HHPU). The resins were characterized by Fourior-transformed infrared spectroscopy(FTIR) and ¹H nuclear magnetic resonance(¹H NMR). The results indicate the successful synthesis of the production. Then the resins were used as oligomers to prepare damping coatings. Dynamic mechanical analysis(DMA) results show that the two cured resins of UV-HPU and HHPU have a high loss tangent(tanδ≥1.0), wide ranges of temperature(tanδ≥0.5, 50 ℃) and wide ranges of frequency(20-160 Hz). Thermal gravimetric analysis(TGA) results indicate that HHPU coatings have a higher thermal stability than UV-HPU coatings. The FTIR of the hybrid coatings indicate the hydrolysis and condensation of trimethoxysilane. The Scanning electron microscopy(SEM) photographs of fracture surface of the hybrid material show that the hybrid material presents homogeneous system without obvious inorganic particle forming.

Key words: Hyperbranched polyurethane, Damping coating, Hydrolysis and condensation