NC State
BioResources
  • Researchpp 1509-1516Wong, Z., Chen, K., and Li, J. (2010). "Formation of vanillin and syringaldehyde in an oxygen delignification process," BioRes. 5(3), 1509-1516.AbstractPDF
    The formation of vanillin and syringaldehyde during an oxygen delignification process was evaluated. The cleavage of conjugated Cα-Cβ bonds in phenolic lignin caused by the attack of oxygen leads to the formation of aromatic aldehydes and ketones. The formation mechanism was confirmed by the organic compounds identified in the spent liquor by GC/MS. Additionally, the formation of aromatic aldehydes and ketones of hardwood, softwood, and grass was investigated. The results showed that the formed aromatic aldehydes and ketones were related to the units of lignin structure. Among the aromatic aldehydes and ketones present in the spent liquor from oxygen delignification, vanillin and syringaldehyde are of high content, making the spent liquor a potential resource for vanillin and syringaldehyde production.
  • Researchpp 1517-1529Rekaby, M. M., El-Thalouth, I. A., Rahman, A. A. H., and El-Khabery, S. A. E. (2010). "Technological evaluation of carboxymethyl sesbania galactomannan gum derivatives as thickeners in reactive printing," BioRes. 5(3), 1517-1529.AbstractPDF
    Galactomannan gum isolated from the seeds of sesbania was subjected to chemical modification via carboxymethylation in non-aqueous medium using monochloroacetic acid under the catalytic action of sodium hydroxide. The obtained derivatives were subjected to measuring the degrees of substitution (D.S.), rheological properties of their pastes, and evaluated as thickeners in printing cotton fabrics with reactive dyes. Highly substituted derivatives could be used successfully as thickening agents in printing cotton fabrics either alone or in admixture with sodium alginate. Prints acquire soft handle, colour strength (K/S), and fastness properties nearly identical to corresponding samples that were printed using sodium alginate.
  • Researchpp 1530-1541Zhou, Y., Renneckar, S., Pillai, K. V., Li, Q., Lin, Z., and Church, W. T. (2010). "Layer-by-layer nanoscale bondlines for macroscale adhesion," BioRes. 5(3), 1530-1541.AbstractPDF
    The objective of this study was to test the bonding performance of nanoscale bondlines, which were fabricated with polyelectrolytes by layer-by-layer assembly process onto wooden substrates. In this study, environmental scanning electron microscopy (ESEM) was used to characterize adsorbed multilayers of polyacrylic acid and polyallylamine hydrochloride on the wood surface. Cross-linking between PAA and PAH layers at various temperatures was studied using Fourier Transform Infrared Spectroscopy (FTIR). The evaluation of polyelectrolyte multilayers as bonding agents for wood was conducted through compression shear block and flexural bending tests. Altogether, this research demonstrates a route to utilize nanoscale coatings as bonding agents.
  • Researchpp 1542-1553Azizi Mossello, A., Jalaluddin, H., Resalati, H., Rushdan I., Paridah, M. T., Fallah Shamsi, S. R. and Ainun, Z. M. A. (2010). "Soda-anthraquinone pulp from Malaysian cultivated kenaf for linerboard production," BioRes. 5(3), 1542-1553.AbstractPDF
    The goal of this study was to prepare soda- anthraquinone pulp from kenaf whole stem and to compare the resultant core and bast pulps for linerboard production. Pulping was done under mild cooking conditions (active alkali 12-15%) with a cooking time of 30-90 min and a temperature of 160ºC. During the pulping process, kappa numbers ranged from 56.0 to 20.6, while total yields varied from 58.4 to 54.2% with a rejection rate of 2.3 to 0.1%. Based on the quality of pulp produced, kappa numbers 49.4 and 25.4 was selected as symbolic of high and low pulps respectively. The results of the study revealed significant difference between the properties of core, whole stem (KHK and KLK), and bast pulps. Core pulps with low freeness and high drainage time the study found produced sheets with greater density, tensile index, burst index and RCT, with lower light scattering coefficient and tear index than bast pulp. Whole stem pulps showed properties between those of core and bast pulps. Moreover, KLK with high drainage time produced papers with significantly higher strength properties than KHK.
  • Researchpp 1554-1564Zamani, A., and Taherzadeh, M. J. (2010). "Production of low molecular weight chitosan by hot dilute sulfuric acid," BioRes. 5(3), 1554-1564.AbstractPDF
    A new method was developed for production of low molecular weight chitosan, in which high molecular weight chitosan was treated with dilute sulfuric acid at 120°C. Chitosan was dissolved in the acid solution in a few minutes, and as depolymerized to low molecular weight chitosan by longer times. Low molecular weight chitosan was recovered from the acid by cooling down the solution and increasing the pH to 8-10. A low molecular weight chitosan with Mv (viscosity average molecular weight) of 174×103 was prepared from a high molecular weight chitosan (Mv = 1,388×103) with 82% recovery by using 72 mM sulfuric acid solution for 30 min. Increasing the time to 240 min reduced the Mv to 24×103, though the recovery of chitosan was reduced to 54%. Higher concentrations of acid (216 and 360 mM) resulted in higher depolymerization degrees and lower recoveries of chitosan in identical treatment times. Analysis of glucosamine and N-acetyl glucosamine showed that the prepared low molecular weight chitosan had more than 80% purity.
  • Researchpp 1565-1580Zhao, X., van der Heide, E., Zhang, T., and Liu, D. (2010). "Delignification of sugarcane bagasse with alkali and peracetic acid and characterization of the pulp," BioRes. 5(3), 1565-1580.AbstractPDF
    Sugarcane bagasse was delignified with alkali and peracetic acid in a two-stage process to obtain pulps with high yield and low kappa number. The experimental results indicated that alkali pretreatment prior to peracetic acid (PAA) delignification could significantly reduce PAA loading by partially removing lignin and swelling the fibers. An optimum condition for the two-stage delignification was obtained for pulping of sugarcane bagasse. The pulps were further characterized by chemical composition analysis, strength property tests, Fourier Transform Infrared Spectroscopy (FTIR), X-Ray Diffraction (XRD), and Thermal Gravimetric Analysis (TGA). It was found that the alkali-PAA process could be conducted under milder conditions with resulting higher pulping selectivity, higher degree of polymerization (DP), and superior mechanical properties of pulps, compared to the kraft pulping process. Both kraft pulps and alkali-PAA pulp had similar FTIR spectra, XRD spectra, and TGA (DTG) curves. However, further analysis indicated that the alkali-PAA pulp had higher infrared crystallization index and cellulose crystallinity.
  • Researchpp 1581-1594Chen, H., Chen, Y., Zhan, H., and Fu, S. (2010)."Enhanced biodegradation of pulping effluents by a statistical experimental design using microbial consortia," BioRes. 5(3), 1581-1594.AbstractPDF
    Statistically based experimental designs were used to construct a mixed-culture community for maximizing the chemical oxygen demand (COD) degradation of pulping effluents by the use of six different strains, i.e., Agrobacterium sp., Bacillus sp., Enterobacter cloacae, Gordonia, Pseudomonas stutzeri, and Pseudomonas putida. Significant effects of single and mixed strains on COD degradation were quantified first by applying a fractional factorial design (FFD) of experiments, and four strains were selected as the main driving factors in the process of biodegradation of effluents. Then the Steepest Ascent method was employed to approach the experimental design space, followed by an application of response surface methodology to further optimize the proportion of cell concentration for different strains in pulping effluent. A quadratic model was found to fit COD removal efficiency. Response surface analysis revealed that the optimum levels of the tested variables for the degradation of COD, and optimized cells concentrations (OD600) of four strains in mixed-culture community were 0.35 Agrobacterium sp., 0.38 Bacillus sp., 0.43 Gordonia sp., and 0.38 P. putid., respectively. In a confirmatory experiment, three test runs were performed by using the optimized conditions, and a COD removal efficiency of (65.3 ± 0.5)% was observed, which was in agreement with the prediction.
  • Researchpp 1595-1604Azizi Mossello, A., Harun, J., Ibrahim, R., Resalati, H., Shamsi, S. R. F., Tahir, P. M., and Yusoff, M. N. M. (2010). "Evaluation of linerboard properties from Malaysian cultivated kenaf soda-anthraquinone pulps versus commercial pulps," BioRes. 5(3), 1595-1604.AbstractPDF
    Malaysian cultivated kenaf has been identified as a suitable raw material for linerboard production. This study examines the soda-antraquinone (soda-AQ) pulp of kenaf fibers versus old corrugated container (OCC) and unbleached softwood kraft pulps as the main sources for linerboard production. The results showed significant differences among the pulp properties. The unbleached kraft pulp with very high freeness required high beating to reach an optimized freeness and produced paper with the highest strength properties, except for tear resistance. The OCC gave paper with the lowest strength properties. In the case of kenaf fractions, bast pulp with high freeness needed less beating than softwood and produced paper with high tear resistance. Core fiber, which had the lowest freeness and highest drainage time, led to paper with high strength but very low tear resistance. Kenaf whole stem pulp showed intermediate properties between core and bast and close to those of unbleached softwood pulp, but with very lower beating requirement. Finally, kenaf whole stem, due to its strength properties, moderate separation cost, and simple pulping process, was judged to be more suitable for commercialization for linerboard production in Malaysia.
  • Researchpp 1605-1617Han, W., Chen, K., Yang, R.-D., Yang, F., Zhao, C., and Gao, W. (2010). "Utilization of bagasse fiber for preparation of biodegradable flame retarding composites (BFRCS)," BioRes. 5(3), 1605-1617.AbstractPDF
    Bagasse is a renewable resource characterized by its low cost and environmental friendliness. In this work a novel technological process was proposed to make flame retarding composites (BFRCs) by using bagasse fiber. The bagasse was disintegrated by twisting it up and applying high consistency refining, and then it was used to prepare BFRCs via hot pressure. Chemical groups and thermal properties of bagasse fiber were studied through the use of FTIR spectroscopy, a universal mechanical testing machine, and TGA, while properties of BFRCs were also analyzed by SEM, and the surface water resistance and burning characteristics were measured. Results showed the pyrolysis temperature of bagasse fibers to be about 273oC. Chemical groups were not changed, while the content of groups was reduced a little during the manufacturing process. The BFRCs showed good performance for water resistance, and the optimum value was 1.7 g. They also had good flame retardant performance. The index of flame spread was 13.6 and the smoke index was 108, which reaches Class A by the ASTM E84-08 Standard.
  • Researchpp 1618-1625Kabir, M. A., Huque, M. M., Islam, M. R., and Bledzki, A. K. (2010). "Mechanical properties of jute fiber reinforced polypropylene composite: Effect of chemical treatment by benzenediazonium salt in alkaline medium," BioRes. 5(3), 1618-1625.AbstractPDF
    Raw jute fiber was treated with o-hydroxybenzenediazonium salt (o-HBDS) in alkaline media. Raw and modified jute fiber were used to prepare composites by mixing with polypropylene (PP) plastic in different weight fractions (20, 25, 30, and 35%) of jute fiber. The mechanical properties except elongation at break of o-HBDS-treated (in alkaline medium) jute fiber-PP composite were higher than those of PP alone, raw jute fiber-PP composites, and alkali-treated jute fiber-PP composites. The elongation at break of treated jute-PP composite decreased to a large extent as compared to that of PP. The increase of tensile strength, tensile modulus, flexural strength, flexural modulus, and Charpy impact strength were found to be exceptionally high (in some cases ~200%) as compared to those of literature values.

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