Study by thermal analysis of composites prepared from silica gel, furfuryl alcohol and acetaldehyde

Abstract

Composites from furfuryl alcohol, acetaldehyde and silica gel were prepared with trifluoracetic acid as a catalyst. The composites were studied by TGA and DSC. The TGA results showed three main losses of weight, the first of which was ascribed to water. The percentage of polymer in the composites reached a limit value, independently of the ratio of furfuryl alcohol/acetaldehyde used. The layer of polymer that covers the silica was not completely cross‐linked. The composites contain soluble oligomers with 97: M n < 580 g mol−1, that could be extracted with THF. The soluble fraction of composites prepared from mixtures of furfurylic alcohol and acetaldehyde decreased as the proportion of the acetaldehyde increased. The DSC of the samples indicated a Tg between −8 and −15 °C that disappeared after an extraction with THF. The DSC of the oligomers removed showed a possible Tg at 13 °C and an exothermic peak between 70 and 170 °C which corresponded to an enthalpy of 326.1 J g−1. © 2003 Society of Chemical Industry

Use of Poly(furfuryl alcohol) in the Fabrication of Nanostructured Carbons and Nanocomposites

“…157 The simultaneous formation of a cross-linked PFA through cationic polycondensation of FA and the silica phase from the acid-catalyzed solgel process of TEOS effectively avoided a macrophase separation during the carbonization reaction. 71,110,158,159 The silica/ carbon hybrid offered the opportunity in forming mesoporous silica or carbon materials by removing the undesired component either by HF/NaOH or oxygen. 110,111 Furthermore, Si-C-O based matrixes were developed through copolymerization of FA and hydrolyzed TEOS to fabricate fiber-reinforced composites.…”

“…Penetrating carbon/silica hybrid materials were fabricated by thermal transformation of homogeneous PFA/silica hybrid xerogel . The simultaneous formation of a cross-linked PFA through cationic polycondensation of FA and the silica phase from the acid-catalyzed sol−gel process of TEOS effectively avoided a macrophase separation during the carbonization reaction. ,,, The silica/carbon hybrid offered the opportunity in forming mesoporous silica or carbon materials by removing the undesired component either by HF/NaOH or oxygen. , Furthermore, Si−C−O based matrixes were developed through copolymerization of FA and hydrolyzed TEOS to fabricate fiber-reinforced composites. The composites exhibited noncatastrophic fracture because the fiber damage at elevated temperature was effectively avoided …”