Abstract:

A new type of optically active polyurethanes (R-BPU and S-BPU) containing 1,1'-binaphthyl were prepared from chiral 1,1'-binaphthol(BINOL) and 2,4-toluene diisocyanate(TDI) by the hydrogen transfer addition polymerization. The polymers obtained were characterized with FTIR, ¹H NMR, UV-Vis, CD, DSC/TGA and so on. The results showed that in the polymeric process, the intrinsic viscosity and the [α]25D of the optically active polyurethanes obtained increased with the enhancement of the optical purity of the BINOL. And the polymers showed an optical stability, the optically rotation of both of the S-BPU and R-BPU could reach -78.0° and +54.6°(DMF, L=10 cm, c=0.25 g/100 mL). The glass transformation temperatures(T_g) of S-BPU and R-BPU reached 258.4 and 286.6 ℃ respectively, meanwhile the thermal decomposition temperatures(T_d) got to 305.6 and 323.6 ℃ and both of whose thermal decomposition temperatures improved more than 100 ℃ according to general PUs. Therefore, the target polymers exhibited good thermal properties, the infrared emissivity reached 0.618 and 0.682, and they displayed a low infrared emissivity.

Key words: Polyurethanes, Binaphthol, Hydrogen transfer addition polymerization, Optical activity