Jett C. Arthur

Cellulose Graft Copolymers

Abstract Graft copolymerization reactions of fibrous cellulose with vinyl monomers were initiated at free radical sites formed on the cellulose molecule by interaction with high-energy radiation, by reaction with Ce4+ ions in acidic solution, or by H abstraction by ·OH radicals fromed by reaction of Fe2+ ions with HLOz in aqueous solution. The effects of experimental conditions on the nature, half-lives, location of these free radical sites on the cellulose molecule, and on the copolymerization reactions were studied by the use of electron spin resonance spectroscopy. The molecular weights of the grafted polymers varied over a range from about 3 × 104 to 1 × 106. The distributions of the grafted polymers within the fibrous cellulosic structure were determined. Some of the changes in physical properties of the cellulose graft copolymers, as compared with cellulose, were decreased permanent set, development of thermoplasticity, decreased stiffness, increased rot resistance, and increased abrasion resistance.

Peanut protein; isolation, composition, and properties.

Publisher Summary This chapter discusses the peanut protein isolation, composition, and properties. Worldwide production of peanuts exceeds 10,000,000 tons annually, with about 10% of the crop being grown in the United States. The protein content of the nuts is about 25%, which makes the peanut a significant source of vegetable protein for foods, feeds, and industrial products. Peanut protein consists of two principal fractions, arachin and conarachin. Arachin is a dissociation system, and its apparent physical chemical properties are dependent on the state of equilibrium existing between the associated and dissociated species. The chemical treatments is devised for stabilizing derived products, very little information is available on the chemical reactions of the proteins. The nutritional value of peanut protein compares favorably with other vegetable proteins; however, when compared with animal proteins, peanut protein is found to be deficient in lysine and methionine. Fibers, glues, sizings, and other industrial products have been made experimentally from peanut protein.

Grafting Studies on Cotton Cellulose

Abstract Graft copolymerization reactions of vinyl monomers with fibrous cotton cellulose that were initiated at free-radical sites formed on the cellulose molecule are discussed. The effects of experimental conditions on the methods of initiating these free-radical reactions and on the location of these sites on the cellulose molecule are outlined. Some of the properties of the fibrous cellulose graft copolymers are discussed.

Thermally Initiated Free-Radical Oxidation of Cellulose

Purified cotton cellulose was heated in the resonant cavity of the electron spin resonance spectrometer in static nitrogen, flowing nitrogen, and flowing air and in vacuum. The formation of free radicals in the samples of cotton was monitored at temperatures below 300°C. Cotton was treated with chemical additives and then heated in static nitrogen at atmos pheric pressure. At the same temperature of heating, a much greater concentration of free radicals was formed in purified cotton heated in static nitrogen than in cotton heated in flowing nitrogen or in vacuum. The rate of free-radical forma tion in cotton heated in flowing nitrogen was constant throughout the heating period. Cotton, heated at the same tem peratures and times in flowing air or in static nitrogen, showed a greater concentration of free radicals than cotton heated in flowing nitrogen. The effects of additives or the application of vacuum on the apparent energy of activation for the formation of free radicals in heated cotton were also investigated. The amount of char formed during pyrolysis, as indi cated by the intensity of the free-radical signal, was much greater for samples which contained additives or which were allowed to trap decomposition products than for untreated cotton purged free of volatile decomposition products, as they were formed.

Synthesis of some furoic and thenoic esters of the methyl d-Glucopyranosides, and their stability to high-energy radiation

Abstract The esters obtained by complete esterificatlon of methyl D-glucopyranosides with, respectively, 2-furoyl chloride (β-, 1: α-, 2), 2-furanacryloyl chloride (β-, 3: α-, 4) 5-bromo-2-furoyl chloride (β-, 5: α-, 6) 2-thenoyl chloride (β-, 7: α-, 8) 5-methyl-2-thenoyl chloride (β-, 9: α-, 10) 5-bromothiopheneacryloyl chloride (β-, 11: α-, 12) and 2-thiopheneacryloyl chloride (β-, 13: α-, 14) were subjected to irradiation (2.8 x 1019 eV/gh) in the solid state to a dosage of 7.1 x 1020 eV/g. The e.s.r. spectra of irradiated (irr.) methyl α- and β- d -D-glucopyranoside and irr. esters 1-14 were examined to determine the nature of the radiation damage: those of the unsubstituted d -glucopyranosides contain one very strong doublet and one very strong singlet, indicating that cleavage of the C-I-O bond (doublet) and dehydrogenation of the C-I-H bond (singlet) had occurred. The e.s.r. spectra of irr. furoates 1 and 2 contain strong doublets. but those of 3-6 have none, showing that the glycosidic bonds in the latter are highly stable to radiation damage, but those in 1 and 2 are stable compared to that in methyl α- d -glucopyranoside. The e.s.r. spectra of the irr. thenoic esters indicated that glycosidic bonds to 11 and 12 are highly stable to radiation initiated cleavage (absence of doublets), those in 7-10 are fairly stable (weak doublets), and those in 13 and 14 are more stable (strong doublets) than that in methyl α- d -glucopyranoside (very strong doublet) Radiation-initiated, dehydrogenation reactions were decreased for 7 and 8 (very weak singlets), 9 and 10 (very weak, and weak singlets), and 11 and 12 (strong singlets). compared with those of methyl α- d -glucopyranoside, 13, and 14 (very strong singlets). The radiation stability of these esters may arise from intramolecular transfer of energy to the ester groups, and be followed by dissipation of the energy. The anomeric form of methyl d -glucopyranoside has no influence on the localization of the energy.

Electron-spin resonance study of some irradiated D-glucopyranosides

Abstract The e.s.r. spectra generated in methyl α- D -glucopyranoside (1) and some selected derivatives thereof by high-energy radiation have been examined to determine the nature of the radiation damage. Evaluations of the e.s.r. spectra of irradiated methyl tetra-O-acetyl-α- D -glucopyranoside (2), methyl tetra-O-[(p-ethoxycarbonyl)benzoyl]-α- D -glucopyranoside (3), methyl tetra-O-(p-methoxybenzoyl)-α- D -glucopyranoside (4), methyl tetra-O-(p-nitrobenzoyl)-α- D -glucopyranoside (5), methyl tetra-O-(ochlorobenzoyl)-α- D -glucopyranoside (6), methyl tetra-O-p-tolylsulfonyl-β- D -glucopyranoside (7), methyl tetra-O-nicotinoyl-α- D -glucopyranoside (8), and methyl tetra-O-(phenylcarbamoyl)-α- D -glucopyranoside (9) contained mainly one type of stable free-radical, together with some secondary radical in low concentration. The e.s.r. spectrum of compound 1 consisted of one doublet and one singlet; this observation was explained by assuming that the free electron position is at C-1, so that the cleavage of the C-1O glycosidic bond would give rise to the doublet, and the dehydrogenation of the C-1H bond would give rise to the singlet. For most of the substituted D -glucopyranosides studied, irradiation gave singlet spectra which were explained by assuming the radical site to be C-1 (by the dehydrogenation of the C-1H bond). The aromatic groups present in the substituted D -glucopyranosides were known to protect the glycosides from radiation damage1. In the aromatically substituted D -glucopyranosides, no reducing power was measurable, even when the compounds were irradiated to dosages as high as 5.2 x 1021 eV/g; this was additional evidence that no cleavage of the C-1O glycosidic bond occurs during irradiation of these compounds. The absence of hyperfine splitting of the free electron at C-1 with H-2 was explained by a change in the conformation of the molecule after H-1 had been cleaved. Displacement of the hydrogen atoms would then occur to remove any deformation of the ring caused thereby; this would remove H-2 from the vicinity of the unpaired electron at C-1. No thermally induced free-radicals could be detected in these compounds, unless they were heated to charring.

Synthesis and properties of cellulose furoates. Nucleophilic displacement reactions of bromo-substituted cellulose furoates with tertiary amines☆

Abstract Cellulose furoates were prepared by the reaction of purified cotton cellulose with 2-furoyl chloride, 5-bromo-2-furoyl chloride, 5-methyl-2-furoyl chloride, and 2-furanacryloyl chloride in pyridine as the acid scavenger, with N,N-dimethylformamide as the diluent. The bromo-substituted cellulose furoates underwent nucleophilic displacement reactions with pyridine, N,N-dimethylcyclohexylamine, and triethylamine to give the corresponding quaternary salts. Infared spectra and physical properties of the fibrous cellulose furoates are reported. The mechanism of the nucleophilic displacement reaction is discussed.

Synthesis and properties of cellulose 2-thenoates. Nucleophilic displacement reactions of bromo-substituted 2-thenoates of cellulose with tertiary amines☆

Abstract The 2-thenoate and some substituted 2-thenoates of cellulose were prepared by the reaction of purified cotton cellulose with 2-thenoyl chloride ( 1 ), 5-methyl-2-thenoyl chloride ( 2 ), 2-thiopheneacryloyl chloride ( 3 ), 5-bromo-2-thenoyl chloride ( 4 ), and 5-bromo-2-thiopheneacryloyl chloride ( 5 ), in pyridine as the acid scavenger, with N , N -dimethylformamide as diluent. The bromo-substituted 2-thenoates of cellulose, obtained by reaction with 4 and 5 , respectively, undergo nucleophilic displacement reactions with pyridine, N , N -dimethylcyclohexylamine, and triethylamine to give the corresponding quaternary salts; the mechanism of the nucleophilic displacement reaction is discussed. The infrared spectra and other physical properties of the fibrous 2-thenoate and substituted 2-thenoates of cellulose are reported.

Reactions of carbohydrates, including cellulose, with boron alkoxides under anhydrous conditions

Abstract The reactions under anhydrous conditions of methyl α- d -glucoside, methyl α- d -mannoside, sucrose, cellobiose, O -methylcellulose, and purified cotton cellulose with such boron alkoxides as boron ethoxide, boron propoxide, and boron isopropoxide were investigated. The neat boron alkoxide, or a solution of the alkoxide in the parent alcohol, benzene, pyridine, ethylenediamine, or pyridineethylenediamine was used as the solvent in different experiments. With increase in molecular weight, reaction of the carbohydrate with boron alkoxides (neat, in benzene, or in the parent alcohol) either did not occur or was decreased, its extent being very low for higher members. In pyridine or ethylenediamine, the reactivity of carbohydrates toward boron alkoxides was increased. Cellulose did not react with the neat alkoxides, and, in pyridine, reacted with them to only a small extent, but in ethylenediamine, cellulose (both ground and in fiber form) reacted with the alkoxides.

Rot Resistance of Some Aromatic Derivatives of Cotton Cellulose

We have previously reported the radiation resistance of fibrous cotton cellulose containing benzhydryl, trityl, benzoyl, naphthoyl, cinnamoyl, and carbamoyl groups [2-5, 12]. Based on excitation and fluorescence spectra of substituted. glycosides [2, 8-11, 13] and subsequent weather-resistance testing, we have shown that only the fibrous cellulose containing benzoyl groups had weather resistance [4]. Earlier, others had also shown that fibrous cellulose containing cinnamoyl groups were not weather resistant [7, 14]. \Ve have found that fibrous cotton cellulose containing cinnamoyl, naphthoyl, benzhydryl, and trityl groups, prepared as previously described [5], have rot resistance in soil burial tests [1(a)] (Table I). It would appear that the substitution of some aromatic groups on cellulose