Saeid Najafi-Shoa - Department of Polymer Engineering, Sahand University of Technology, Tabriz, Iran
Hossein Roghani-Mamaqani - Institute of Polymeric Materials, Sahand University of Technology, Tabriz, Iran
Mehdi Salami-Kalajahi - Institute of Polymeric Materials, Sahand University of Technology, Tabriz, Iran
Reza Azimi - Department of Chemical Engineering, Sahand University of Technology, Tabriz, Iran

Thermal properties of epoxy resin (E) were improved by its incorporating into silica/siloxane network in the presence of carbon nanotube (CNT). At first, CNT xerogel (CNTX)/E composite was prepared by curing E in the presence of CNTX (ECNTX sample). Then, E is modified with (3-isocyanatopropyl)triethoxysilane (IE) or tetraethyl orthosilicate (TEOS) oligomer (TE) for its incorporating into a hybrid network of CNTcontaining silica/siloxane network (IECNTX or TECNTX samples). For this purpose, a bifunctional modifier of 1,1 -(hexane-1,6-diyl)bis(3-(3-(trimethoxysilyl)propyl)urea) (HDBTMSPU) was synthesized by coupling reaction of a hexamethylene diisocyanate and two (3-aminopropyl) trimethoxysilane molecules. CNTX was prepared by incorporation of HDBTMSPU-modified CNT (FCNT) into silica/siloxane network by using HDBTMSPU and TEOS. IE (TE), FGO, HDBTMSPU, and TEOS were also used in preparation of hybrid products. Three types of composites were compared in their thermal degradation temperature and char content. TGA results showed that the hybrid of IE, FCNT, and silica/siloxane network shows higher thermalproperties. Char residue is increased 17.54 % by only 4 wt% loading of FCNT in IE resin (IEGX1).

Epoxy resin; carbon nanotube, silica xerogel; thermal properties