LAUSR

A triethanolamine (TEA)–azodiisobutyronitrile (AIBN) mixture was applied to the manufacturing of a low-density unsaturated polyester resin (LDUPR) at a low temperature ranging from 53 to 66 °C. Hydrogen-bonding activation in the TEA–AIBN mixture was put forward, and this agreed with the NMR and Fourier transform infrared (FTIR) spectroscopy results. A heat balance in the curing process of a vinyl ester unsaturated polyester resin (UPR) was examined and characterized by differential scanning calorimetry, FTIR spectroscopy, and scanning electron microscopy. The TEA–AIBN mixture decomposed easily because of the hydrogen-bonding action between TEA and AIBN. The heat release of the activated AIBN decomposition led to the early endothermic polymerization of the vinyl ester UPR. Hydrogen-bonding activation followed by the heat-balance process enabled us to manufacture the LDUPR at low temperature. The optimal parameters of LDUPR manufacturing, including a ratio of TEA to AIBN of 0.4 and a dosage of TEA–AIBN mixture of 2.5 phr at a curing temperature of 60 ± 1 °C, were defined by the testing of the apparent density (ρ) and compressive strength of LDUPR. Under these conditions, ρ was 0.39 ± 0.01 g/cm3, and the specific compressive strength was 33.92 ± 1.31 MPa g−1 cm−3. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44797.