Luo Yun-bai

Vinyl-modified hyperbranched polyether cross-linked hydroxyl-terminated polybutadiene-based polyurethane membrane for pervaporation recovery of butanol

Hyperbranched polyether was synthesized and vinyl modified using the one-pot method and characterized by Fourier transform infrared spectroscopy (FTIR), hydrogen nuclear magnetic resonance spectroscopy, and thermogravimetric analysis (TGA). The as-obtained polyether was used to cross-link hydroxyl-terminated polybutadiene-based polyurethane (PU). The PU was characterized by FTIR, TGA, scanning electron microscopy, water contact angle, tensile tests, and swelling properties. The PU was used in pervaporation (PV) recovery of butanol from its dilute aqueous solution. The PV performance was determined using the separation factor (α) and permeate flux (F p). With a membrane thickness of 31 μm, the separation factor of the membrane was up to 10.2 with a total flux of 320.7 g m−2 h−1 at 70°C.

Analysis of SF 6 decomposition products by insulator flashover to detect the insulator condition

An evident fault occurs on the insulator surface accompanied by a remarkable insulator strength decline were detected, which is probably caused by the SF6 decomposition products in the insulator flashover process. A simulation of flashover process on the insulator surface was built in this article in order to analyze the possible decomposition product of SF6. As a result, several specific decomposition products (eg. CS2) of the primary insulator material were discovered, which make it possible to assume the reaction mechanism and further application of insulator flashover process via analysis of specific gas such as CS2.