Carbon-13 NMR study of curing in furfuryl alcohol resins

Abstract

A13C CP/MAS NMR study of furfuryl alcohol resins is reported. A conformational rigidity is found for uncured or less cured resins. The contents of methylol groups and dimethylene ether linkages are found to be very small. It is postulated that cross-linking involves the breaking of methylene bridges in the curing process. Further confirmation is given that the major cross-linking processes that occur during curing involve linkages with bridging CH2 groups, rather than substitution at the 3-and 4-positions of furan rings in the resins.

Flame Retardance and Physical Properties of Novel Cured Blends of Unsaturated Polyester and Furan Resins

“…Various reactions have been proposed for the crosslinking of fufuryl alcohol resins [24][25][26], including reaction of carbocationic chain ends with preformed methylene links; see Scheme 4, Reaction (4). However, Choura et al found no evidence for Reaction (4) when tested with model compounds.…”

Furfurylated wood: impact onPostia placentagene expression and oxalate crystal formation

“…FA is often obtained from agricultural waste such as sugar cane, corn cobs, sunflower or birch chips (Maciel et al 1982;Chuang et al 1984;González et al 1992González et al , 2002Lande et al 2008). According to Lande et al (2004), furfurylation of wood provides protection against bio-degradation (fungi, bacteria and marine borers) without reliance on biocidal treatments.…”

Characterizations of furfuryl alcohol oligomer/polymerization catalyzed by homogeneous and heterogeneous acid catalysts

“…According to the reported polymerized structures, the humin structure contains methylene linkage furan rings [26,27], dimethylene ether linkage [20], γ-diketone [28], conjugated double bond sequence [3,23,29], and branched species [30,31]. Even though proposed structures were contradictory in some respects, the observed sample's color, which is dark gray or black, and viscous character were commonly agreed.…”