A study of the low molecular weight components of furfuryl alcohol polymers

Abstract

SynopsisLow molecular weight components of both an acid-polymerized and a 7-alumina polymerized furfuryl alcohol polymer were separated by gas chromatography utilizing a Porapak type P-S column packing. The identities of the separated polymer components were established by infrared spectroscopy, mass spectrometry, and nuclear magnetic resonance analysis. Volatile constituents found to be common to both furfuryl alcohol resin types were: furfuryl alcohol, water, difurylmethane, difurfuryl ether, and 2,5di-furfurylfuran. Also, 5-furfurylfurfuryl alcohol was found to be present only in the acidpolymerized resin, and 4-furfuryl-2-pentenoic acid r-lactone was a constituent only of the 7-alumina-polymerized resin. Contrary to expectation, no esters of levulinic acid were found among the low molecular weight components of the 7-alumina-polymerized furfwyl alcohol polymer. INTRODUCTIONE'urfuryl alcohol polymers are thermosetting resins which have been utilized as binder, coating, and impregnating materials. I n addition to exhibiting excellent heat and chemical resistance when cured, furfuryl alcohol polymers also produce relatively large amounts of carbon when subjected to high-temperature pyro1ysis.l These properties account for the more recent use of furfuryl alcohol resins as binder materials in the manufacture of nuclear-grade graphite. Our interest in the development of improved furfury1 alcohol resin-bonded graphite has led us to further studies of the chemical and physical properties of the resins used in graphite fabrication.The polymerization of furfuryl alcohol is accompanied by many side reactions which, from a chemical point of view, result in the formation of a heterogeneous product. Thus, to attempt an understanding of the behavior of these polymers when used as graphite binder materials, it is necessary to have some knowledge about their chemical composition.As it is experimentally difficult to isolate the larger molecules present in furfuryl alcohol polymers, it was decided that by separating and identifying the low molecular weight components of these polymers, much information concerning the chemical composition of the polymers as a whole could nonetheless be gained. Of course, the assumption must be made that the com- 1438 WEWEHKA, LOUGHKAN, AND WALTEHSposition of the entire polymer is reflected in the composition of its more volatile components. In fact, the low molecular weight components of furfuryl alcohol resins are likely to be of particular importance to us. A recent study concerning the effects of the molecular-size distributions of furfuryl alcohol polymer binders on the properties of graphites made from them2 indicated that the behavior of these binder materials is determined largely by the amount of lower molecular weight constituents present in the polymer. Experimentally, the task of isolating the volatile components of furfuryl alcohol polymers in amounts suitable for further characterization appeared to be well suited to gas chromatography techniques.Furfuryl alcohol polymers are usual...

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

“…We can expect that temperature or acidity was not high enough to overcome an activation energy for FA conversion into oligomer/polymer, while sulfuric acid can convert FA into low molecular oligomer at room temperature [42]. Wewerka et al, reported difuryl methane, difurfuryl ether, 4-furfuryl-2-pentenoic acid, and 2,5-difurfuryl furan formation from FA over a γ-alumina catalyst at 170 o C [43]. Based on this article, we can hypothesize that reaction temperature is the critical parameter of FA oligomer/polymerization reaction over the metal oxide catalysts.…”

Adhesion aspects of levulinic-acid-modified furan polymers to crystalline zinc phosphate metal surfaces

“…2H20-H3P04-H20 oxidizing solution at 60°C for 1, 3,6, and 24 h, respectively. SEM photomicrographs of the treated metal surfaces (Fig.…”

(Aryl)(2-furyl)alkanes and their derivatives, 20. Synthesis of symmetric bis- and tris(2-furyl)methanes

“…The acid-promoted oligomerization of furfuryl alcohol gives a mixture of products, among those bis(2-furyl)methane has been isolated in low yield. 11 It has been also found that the reaction of (5-aminomethyl-2-furyl)methanol with 5.1 M hydrochloric acid furnished bis(5-aminomethyl-2-furyl)methane as a minor product. 12 Hydrothermolysis of (5-methyl-2-furyl)methanol at 300 ºC and pH ~ 7 produced bis(5-methyl-2-furyl)methane in 15% yield.…”