Pyrolytic Degradation Products of Cellulose.

Abstract

The crude acidic product was purified by filtering through a 1-inch layer of anhydrous potassium carbonate and was fractionated to give a neutral product.Cyclohexylamme Salt of C, Chlorofluorocarboxylic Acid. A solution of 24 grams (0.05 mole) of C, chlorofluorocarboxylic acid in 25 ml. of ethvl ether was added to 5 grams (0.05 mole) of cyclohexylamine in 15 ml. of ethyl ether.The solvent was evaporated and the remaining solid was recrystallized from cyclohexane to give 14 grams (48%) of white solid.Decarboxylation of C, Chlorofluorocarboxylic Acid. A 27-gram charge of C, chlorofluorocarboxylic acid was neutralized with sodium hydroxide, concentrated under a stream of nitrogen, and dried at 105 °C. in a vacuum oven. A 10.7-gram (0.0214 mole) sample of the dry sodium salt was heated in a small distillation apparatus. A liquid product (8.3 grams) distilled at ca. 160°C. as the pot temperature rose from 160°to 300°C. and gave a positive unsaturation test with aqueous potassium permanganate.A redistilled portion had a molar refractivity confirming the structure CF2C1(CFC1CF2)2CF =CF2.CF2C1(CFC1CF2)2CC1= CF2 is indicated by the presence of fluoride in the pyrolysis residue. APPLICATIONSThe chlorofluorocarboxylic acids are resistant to thermal decomposition and are very stable toward strong acids, bases, and oxidants. This stability indicates that the acids or their derivatives will be excellent surfactants in some environments where hydrocarbon surfactants fail.The large number of derivatives of the chlorofluorocarboxylic acids potentially available should provide new classes of materials useful as hydraulic fluids, lubricants, plasticizers, and for other applications where a nonflammable, stable material is required.

Mechanistic Aspects of Phosphorus-Nitrogen Synergism in Cotton Flame Retardancy

“…Essentially the same products are obtained even if the pyrolysis is carried out in an oxidizing atmosphere. Production of large quantities of levoglucosan and other volatiles (collectively called tat) is responsible for the high flammabilSfy of cellulose [11,12]. According to Schuyten e1 al.…”

Production of Levoglucosan by Pyrolysis of Carbohydrates

“…Parks et al (1955) proposed that during the pyrolytic decomposition of cellulose at elevated temperatures cellulose depolymerizes by scission of the 1 -4-glycosidic linkages and this is followed by an intramolecular rearrangement of monomer units to levoglucosan, which subsequently undergoes fragmentation to form low molecular weight products. This mechanism was later supported by many workers (Berkowitz-Mattuck and Noguchi, 1963;Madorsky et al, 1958;Schwenker and Beck, 1963;Schwenker and Pacsu, 1957).…”

“…Further, levoglucosan, unlike glucose, is known to be stable in alkaline solution. It polymerizes into dimers, tetramers, hexamers, etc., under the influence of heat and catalyst (Carvalho et al, 1959; and forms crystalline ethers (Zrvin and Oldham, 1921;Ruckel and Schwerch, 1966;Zemplhn et al, 1937) as well as crystalline triacetates and tribenzoates (Schwenker and Pacsu, 1957). Levoglucosan is soluble in water, slightly soluble in methanol, ethyl alcohol, acetone, etc., and insoluble in ether.…”

Pyrolysis Smoke Generated Under Low-Gravity Conditions

“…The pyrolysis of these polymers have been shown to result in a wide range of condensable species including polymer chains down to the size of the monomer from which the polymer was synthesized and a wide range of molecular structures resulting from the breaking of bonds in the polymer (lamp wick- Schwenker andPacsu 1956, Ohlemiller et al 1985;Schauer et al 2001;Teflon-Seidel et al 1991; silicone rubber- Buch et al 1998;Caminoa et al 2001;Kumagai and Yoshimura 2001;Kapton-Hatori et al 1996;Pyrell-Ingham andRapp 1964, Woolley 1972). For perhaps the most widely studied of these materials, lamp wick (cellulose), more than 150 products have been identified (Schauer et al 2001).…”