Advanced Materials Research Vols. 236-238

Abstract: The resol-type resin was prepared with a high yield from the liquefied products of walnut shell in phenol, which was reacted with formaldehyde under low alkaline conditions. The effects of reaction temperature and time on the yield and viscosity of the resol resin were investigated. Results showed that the optimum resol resinification conditions were a reaction temperature of 80°C and a reaction time of 2 h. The biomass-based resol resin from liquefied products of walnut shell was successfully applied to produce phenolic foam with diisopropyl ether as the blowing agent, Tween 80 as the surfactant and hydrochloric acid as the catalyst, respectively. The obtained foams showed satisfactory mechanical properties and a uniform fine cellular structure.

Abstract: The liquefaction of cellulose in the presence of phenol without or with sulfuric acid as catalyst was investigated. The liquefied products were characterized by GC/MS and FTIR. Results showed that reaction temperature and reaction time had obvious effects on liquefaction of cellulose. Sulfuric acid showed an excellent catalytic degradation. The chemical compositions of the liquefied products produced using sulfuric acid catalyst or not were almost identical, and the majority of the identified liquefied products were methylene bisphenol and its isomers. During the process of liquefaction, the degradation of cellulose and condensation polymerization occurred at the same time. The last liquefied products were greatly dependent on the reaction conditions.

Abstract: The strain Jgj-1 was isolated from Gaoan bauxite ore. The relations of desilication of the strain Jgj-1 and the pH of solution, temperature, shaking speed, incubation time, particle size were investigated. The results shows the optimum conditions of bioleaching are as following: at 28°C, initial pH value is 7.2, particle size 0.056mm, 200rpm shaking speed, incubation 5-7 days.

Abstract: The primary goal of this study was optimized condition for hydrolyzed of papermaking waste (poplar sawdust) as a potential bio-ethanol source by sulfuric acid pretreatment. Based on 2³ factorial design, fifteen operations were performed by varying on T, t and c (T: hydrolysis temperature, t: hydrolysis time and c: sulfuric acid concentration). The components of the hydrolysate and solid fractions were analyzed by GC, X-RD and SEM, respectively. The results showed that optimal condition was T 44.8°C, t 120min and c 60%, and reducing sugar yield of 43.3% can be obtained. Through GC detection, glucose content of 26.10 g/L and xylose content of 9.00 g/L is available in hydrolyzate for fermentation. The residue crystallinity declined 74.34% from XRD analysis, the fiber structure was destroyed completely by acid hydrolysis from SEM photograph.

Abstract: Bioenergy is a renewable energy with such advantages as low cost, simple construction, and it is also quite economic and effective. The bioenergy application directly displaces greenhouse gas emissions and does not contaminate environment. Based on these characteristics, biomass as a source of bioenergy has been attracting much more concern in recent years. This paper aims to introduce mechanism of biomass gasification, types of gasifiers, applications and research progress at home.

Abstract: The researches about upgrading of methane from biogas by pressure swing absorption are introduced in this paper. Biogas contains 55~70% methane (CH₄) which is the main component of natural gas. If other components of biogas are removed, biogas is upgraded to SNG (Substitute Natural Gas). The processes of upgrading of methane from biogas by PSA or VPSA (Vacuum Pressure Swing Adsorption) are presented. Different techniques which are used for upgrading of biogas are evaluated. Finally, prospect about this process is made.

Abstract: The research presented in the paper focuses on the specific process of Gutta-percha extraction and refinement. Gutta-percha was extracted from the residues of leaves, which is based on the comprehensive utilization technology of Eucommia Ulmoides leaves. After extracted and separated chlorophyll, β-carotene, lignans, aucubin, chlorogenic acid, flavonoid, polysaccharide and proteins, etc. with the method of Multi-stage Countercurrent Extraction, the green leaves changed into the residues, which was then steeped in petroleum ether (whose boiling range is from 60 to 90°C) and generated precipitation in acetone. The results of this research indicate that: Gutta-percha extracted from the residues owns light color, which resolves the big issue that the gum was restricted for deep color in exportation. Besides, the yield of the gum in this experiment is approximate 2.0%, the increasing rate rising by 17.6% compared with 1.7% of other immediate extraction methods’. What’s more, the cost of the process flows introduced in the paper is lower than others, with less consumption, less waste and more efficient solvent circle utilization. And a new way for gutta-percha extraction was presented.

Abstract: Longitudinal and transverse modulus of elasticity(MOE) tests of plybamboo form with different moisture content were performed. The results show that both longitudinal MOE and transverse MOE decrease with the increasing of the moisture content of the plybamboo form, which decrease linearly at low moisture content stage. Curve regression equations of longitudinal and transverse MOE of plybamboo form were constructed by the method of numerical fitting, and linear regression equations at low moisture content stage were also constructed. Decline of plybamboo form strength itself and bonding invalidation lead to the decrease of MOR The results of variance analysis and significance test of four regression equations show that all the regression equations achieve very significant level.

Abstract: β-chitosan preparation from squid pens was carried out using aqueous NaOH with the ultrasonic assistance. Single factor experiments and L₉ (3⁴) orthogonal experiments were used to investigate the effect of three parameters (reaction time, concentration of NaOH and reaction temperature) on deacetylation of β-chitin. The optimal conditions for deacetylation of chitin were reaction temperature 80°C, reaction time 2 h and concentration of NaOH 50%. The optimal conditions allowed deacetylation degree of β-chitin from 71.32% to 92.91%. The β-chitosan from squid pens was confirmed by Fourier transform infrared spectroscopy. The antibacterial activities of the prepared β-chitosans again staphylococcus aureus (S. aureus) and Escherchia coli (E.coli) were then determined and compared by the MIC (minimum inhibitory concentration). Results indicate that β-chitosans with different degrees of deacetylation (DD) possess different antibacterial activity. The growth of S. aureus can be easily inhibited by prepared β-chitosan than E.coli.

Abstract: Using different rank coals as filler, coal-soy protein isolate (SPI) composites were prepared by compression molding processing using glycerol as plasticizer. The structure of the coals used were characterized by Fourier transform infrared (FTIR), ultimate analysis, and surface functional group analysis. The effects of coal structure on the mechanical properties, water resistance, and thermal properties were investigated. The results showed that, in different rank coals, the atomic ratio of oxygen to carbon, carboxylic acid groups, phenolic hydroxyl groups, lactone bonds, and aliphatic chains decreased with coal rank. The strength, water resistance, and glass transition temperature of coal-SPI composites decreased with coal rank. Lower ran coal filler with more reactive functional groups caused the composites strong but brittle. While, higher rank coals provide poor mechanical properties for the composites.