Synthesis of sulfur rich porous material for mercury adsorption and thermal insulation

Abstract

A novel porous material (porous poly (S-r-DVB) co-polymer) pre-dominantly made of sulfur was synthesized via sacrificial template and inverse vulcanization process. Sulfur-salt pre-mix was heated at 165 °C promoting ring-opening polymerization of S8 followed by addition of a crosslinker (DVB). The resultant material was continuously stirred until a highly viscous reddish brown material was formed. The product obtained was allowed to cool down under ambient condition and the salt was successfully leached out using water. The characterization of the material performed by Fourier transform infrared, X-ray diffraction and Raman spectroscopy ascertained the presence of C-S bond and amorphous nature of the product. Porosity of the product was measured and thermal analysis confirmed increase in thermal stability with addition of cross-linker (DVB). Morphological properties were analyzed using scanning electron microscopy. Meanwhile, porous poly (S-r-DVB) co-polymer was used in removing elemental mercury in vapor phase. Poly (S-r-DVB) with 20 wt. % DVB showed maximum adsorption capacity (~151 ug/g) at 60 °C, owing to the high porosity associated with less volume shrinkage. Additionally, adsorption capacity of porous co-polymer was compared to commercial carbons and the result obtained was within the range of commercial adsorbents at 60 °C (90 ug/g -240 ug/g). Owing to the poor thermal conductivity (0.205 W/m K) associated with pure sulfur, thermal conductivity was measured for porous co-polymers. As expected, the presence of pores and crosslinked structure significantly reduced the thermal conductivity of material. Porous (S-r-DVB) copolymer with 50 wt. % DVB showed minimum conductivity (0.048 W/ m K) and was within the range of commercially available insulators.

Date of Award	2016
Original language	American English
Supervisor	Saeed Al Hassan (Supervisor)