The extractive free cherrywood on alkaline extraction gave, in 22.4 per cent yield, a hemicellulose composed of 106-ll4, 1-4 linked β-D-xylopyranose residues with side chains of 4-0--methyl-D-glucuronic acid attached to position 2 of every 7th anhydroxylose. The hemicellulose on hydrolysis yielded a neutral sugar, D-xylose, with traces of D-glucose and rhamnose. D-Xylose was characterized as the crystalline sugar, D-glucose was characterized as its p-nitroanilide, and rhamnose was characterized by electrophoresis and chromatography. An aldobiouronic acid was isolated from the acidic fragments and shown to be 2-0-(4-0-methyl-⍺-D-glucopyranosyluronic acid)-D-xylose by preparation of the crystalline acetate, methyl 2-0-[methyl (2,3-di-0-acetyl-4-0-methyl-⍺-D-glucopyranosyl) uronate ]-3,4-di-0-acetyl-D-xylopyranoside. The hemicellulose was methylated and the product fractionated to give three main fractions which were essentially homogeneous. Hydrolysis of one of the fractions yielded 2,3,4-tri-0-methyl-D-xylose (l mole) characterized by chromatography 2,3-di-0-methyl-D-xylose characterized as the crystalline sugar and anilide, and 2,3-di-0-methyl-D-lyxose characterized as the crystalline sugar and anilide (88 moles); and 2-0 and 3-0-methyl-D-xylose (l mole) characterized by electrophoresis. Traces of two disaccharides and an unknown monosaccharide were also found. A partially methylated aldobiouronic acid, 3-0-methyl-2-0- (2,3,4-tri-0-methyl-⍺-D-glucopyranosyluronic acid)-D-xylopyranose (l6 moles), was isolated and characterized as follows. The methyl ester methyl glycoside was prepared and then reduced to the disaccharlde. The disaccharide was hydrolysed to give 3-0-methyl-D-xylose and 2,3,-tri-0-methyl-D-glucose characterized as their crystalline anilides. Cherrywood hemicellulose resembles other glucuronoxylans isolated from hardwoods such as sugar maple and white birch but there is a higher uronic acid to xylose ratio than is usual for hardwood xylans. It resembles the xylan from white elm more closely in this respect. Recently apple-wood hemicellulose was isolated and shown to be similar to cherrywood hemicellulose. / Science, Faculty of / Chemistry, Department of / Graduate

Quantitative methods for sulphate and Na-base bisulphite micro-pulping and micro-analytical procedures were developed. Raw pulp and pulp carbohydrate yields were correlated with relative position within growth increments of black spruce and Douglas fir. Profiles varied at different pulp yield levels and with pulping process. No profiles were simply correlated with wood micro-specific gravities. Maximum raw pulp and pulp carbohydrate yields within growth increments shifted from earlywood to latewood as yield changed from high (80 ± 5%) to low (45 ± 5%) levels. Delignification rate differed within increments for both pulping processes. In the initial sulphate and Na-base bisulphite cooking stage, latewood lignin seemed to be more easily removed than that from earlywood. At high yield levels (80 ± 5%), the pulp residual lignin contents based on oven-dry pulp followed similar patterns in that maxima were found in early-wood, abruptly decreasing in the transition zone then slightly increasing in the latewood portion. At low yield levels (45 ± 5%), the residual lignin patterns varied slightly, or remained constant throughout the whole increment. Raw pulp yields, residual lignin contents and pulp carbohydrate yields (based on extractive-free water-free wood) were not significantly different for combined data of heartwood and sapwood, the two woods and two pulping processes, except for Na-base bisulphite pulp carbohydrate yields which showed significantly higher values for sapwood. Sulphate raw pulp yields and residual lignin contents obtained by combining data from all cooking levels and wood zones were not significantly different between the two species examined, except for Douglas fir carbohydrate yield which was significantly higher than that of black spruce. For Na-base bisulphite pulping, Douglas fir raw pulp yields and pulp carbohydrate yields were highly significantly greater than those from black spruce, whereas pulp residual lignin was not significantly different. / Forestry, Faculty of / Graduate

A technique is described for improving wood fibre web strength by copolymerization of a hydrocarbon drying oil (CTLA Polymer) within hand-sheets made from pure and admixed forms of high yield chemical (sulfite and sulfate) and groundwood fibres. Oil polymerization can be initiated successfully by prolonged thermal treatment at 145°C, as well as by the novel method of low dosage gamma-ray irradiation. The treatment strengthens inter-fibre bonding. Evidence for copolymerization was sought through assessment of tensile and related strength data on variously treated standard handsheets. Effectiveness of the polymerization on pulp types investigated as initiated by heat and low dosage irradiation is strongly related to surface colloidal and basic physical and mechanical properties of the fibres. Maximum strength parameters were obtained with oil saturated sulfite and groundwood handsheets following polymerization by thermal treatment. Copolymerization efficiency by irradiation, on the other hand, is estimated as 73% for sulfite, 65% for groundwood and 50% for kraft handsheets. Effectiveness of oil polymerization by irradiation was found to be proportional to dosages up to 10⁵rad. As anticipated, limit of strength improvement was not set entirely by intrinsic fibre strength, but was also influenced by surface colloidal properties of the fibres. Blends made from chemical-groundwood fibre mixtures behaved more or less proportional to individual pulp strengths and extent of blending. Copolymerized sulfite-groundwood blends at equal proportions approximated the tensile strength of similar kraft papers suggesting better economy with kraft fibres when papers of limited strength are produced. All other strength parameters (elastic modulus, tensile strain and tensile energy absorption) followed similar trends, or if different were of aid in explaining certain phenomena characteristic to treated fibre webs. The presence of graft copolymer could not be conclusively proven, since both the copolymer and oil homopolymer are insoluble in the usual organic solvents. A dual character of the oil polymer was demonstrated with glass filterpaper and highly purified commercial cellulose fibres. Effectiveness of oil polymerization in highly lignified mechanical pulps was greatly depressed by mild sodium chlorite treatment, although the strength and bonding capacity of such fibres increased considerably. This was taken as direct evidence for the possibility of a lignin-CTLA Polymer copolymer system. Site of chemical reaction has not been described, although means for assessment of such information are suggested. The study proves the usefulness of gamma irradiation as energy source for the copolyerization of drying oils in handsheets as replacement for the prolonged thermal treatment hitherto used by the hardboard industry. Added advantages of irradiation processed copolymerized papers are less discoloration, especially with high lignin content pulps, and lower elastic modulus, a factor clearly objectionable for some paper uses. / Forestry, Faculty of / Graduate

Samples of sawdust from poplar, alder and Douglas fir, were ground past screens ranging in size from 2.21 mm to 0.25 mm (60 mesh). A reduction in particle size significantly increased the in vitro rumen digestibility of poplar, but had little effect on the digestibility of alder or fir. The above woods, plus sludge (a by-product of the pulping process) were treated with NaOH solutions of 2, 4 and 6%. These solutions were used at three treatment periods of 0.5, 1.0 and 1.5 hours, and all treatments were carried out at 1.05 kg/sq cm and 121° C. NaOH treatment significantly increased the in vitro cellulose digestibility of all woods except fir. The optimum treatment conditions for increasing the in vitro cellulose digestibility of all woods were 4% NaOH at the 1.5 hour treatment period, except in the case of alder which was most digestible when treated with 2% NaOH for 1.5 hours. Gamma irradiation increased the in vitro cellulose digestibility of all woods. Alder and fir were most digestible when treated with 2 x 10⁸ rads, but poplar and sludge reached their peak digestibility when exposed to 1 x 10⁸ rads. Irradiation was found to decrease the cellulose and acid detergent fibre (ADF) content of all the woods studied. Acid detergent lignin (ADL) also decreased in response to irradiation in all woods except sludge. Irradiation had no effect on the ash content of any of the samples. Three methods of cellulose analysis were used on both untreated and irradiated wood, and there was a significant difference shown among the methods. The lowest values were obtained using Van Soests' KMnO₄ method, next were the results from Van Soests' 72% Hg₂SO₄ method, and the highest values were obtained using the Crampton and Maynard procedure for cellulose. Two lignin methods were also compared and it was found that the KMnO₄ lignin values were significantly higher than those obtained using the 72% H₂S0₄ method for lignin. / Land and Food Systems, Faculty of / Graduate

Changes in wood chemistry could have significant impact on both environmental and economic aspects of the pulp and paper industry. Consequently, a considerable amount of effort has been devoted to altering lignin content and/or modifing lignin monomer composition, a cell wall component whose removal is a major part of the chemical pulping process. Analysis of poplar transformed with a cinnamate 4-hydroxylase (C4H):ferulate5-hydroxylase (F5H) construct confirmed significant increases in the mole percent syringyl lignin in transgenic lines. Further, this study demonstrated significant increases in pulping efficiency from greenhouse grown transgenic trees. Compared to wild-type pulp, decreases of 23 kappa units (residual lignin) and increases of >20 ISO brightness units were observed in tree lines exhibiting high syringyl monomer concentrations (93.5% mol S). These changes were associated with no significant change in total lignin content or observed phenotypic differences in the trees. Additionally, pulp yields were not affected by the enhanced removal of lignin.. Furthermore, transgenic lines exhibit reduced fibre coarseness and increased cellulose viscosity. These results suggest that C4H-F5H transformed trees could be used to produce pulp for paper with substantially less severe delignification conditions (lower chemical loading or less energy), and that the pulp produced is of comparable quality to that of the wild-type poplar. Consequently, the ecological footprint left on the environment, measured by the amount of deleterious pulping by-products released into the environment may be significantly reduced. / Forestry, Faculty of / Graduate

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