In order to manufacture conductive paper, aniline was polymerized into the micro-pore wall of the pulp fiber by in-situ adsorption polymerization process using ammonium persulfate as oxidant. The effects of different ...
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In order to manufacture conductive paper, aniline was polymerized into the micro-pore wall of the pulp fiber by in-situ adsorption polymerization process using ammonium persulfate as oxidant. The effects of different doping conditions on the performance of conductive paper including the kinds and concentrations of dopants, temperature and time of secondary doping and co-doping were studied in detail. The results showed that organic sulphonic acids (toluene-p-sulfonic acid and sulfosalicylic acid) and sulfuric acid were excellent dopants. The optimum concentration of the dopants was 0.6 mol/L. The optimum temperature and time of secondary doping were less than 35°C and 7.5 hours. Higher temperature and longer time would not only lead to increase the surface resistivity, but also lead to the destruction of pulp fiber matrix. The optimum co-doping effect could be obtained when the mole ratio of toluene-p-sulfonic acid to sulfuric acid was 2:1.
In this paper, aniline was polymerized into the micro-pore wall of the pulp fiber by in-situ adsorption polymerization process in order to manufacture conductive paper. The effects of different reaction conditions inc...
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In this paper, aniline was polymerized into the micro-pore wall of the pulp fiber by in-situ adsorption polymerization process in order to manufacture conductive paper. The effects of different reaction conditions including amount of oxidant(potassium persulfate or ammonium persulfate), reaction temperature and reaction time on the surface resistance of conductive paper were studied in detail. The optimum adsorption polymerization conditions were: polymerization time 105 minutes, reaction temperature 5°C. The mass ratio of oxidant to aniline is dependent on the types of oxidant. When potassium persulfate was used as oxidant, the optimum mass ratio of oxidant to aniline was 1:2 and the surface resistivity of the conductive paper was 481 Ω/cm2. However, the optimum mass ratio of oxidant to aniline was 3:4 and the surface resistivity was up to 108 Ω/cm2 when ammonium persulfate was used as oxidant. Thus, ammonium persulfate is better than potassium persulfate as oxidant.
Taking cyclohexane as the oil phase, DADMAC, AM and AA as the monomers, based on the emulsifying system comprised of nonionic surfactants Span80 and Tween60, effects of monomer concentration, monomer fraction, hydroph...
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Taking cyclohexane as the oil phase, DADMAC, AM and AA as the monomers, based on the emulsifying system comprised of nonionic surfactants Span80 and Tween60, effects of monomer concentration, monomer fraction, hydrophile-lipophile balance(HLB) value, the dosage of emulsifier as well as electrolytes on the stability of inverse microemulsion were studied by method of conductometry and eyeballing. The experimental results show that stable inverse microemulsion system can be formed with the mass fraction monomer in the range of 50% to 65%, the stability of inverse microemulsion continuously increases with the increase of acrylamide based on the fixed mass fraction of the monomers. It is also found that the system with HLB value in the range of 5.36 to 8.54 is stable and is most sable with the HLB value of 7.48, the inverse microemulsion system is more stable when used more emulsifier, additionally, introduction of electrolytes into the system can make particles further fine and enhance stabilization performance.
Following a normal low temperature drying schedule, the small-diameter Birch lumbers （ 1 000mm× 45mm ×30mm） were dried with consecution-heats or intermittent-heating, visual drying defects （bow, crook, tw...
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Following a normal low temperature drying schedule, the small-diameter Birch lumbers （ 1 000mm× 45mm ×30mm） were dried with consecution-heats or intermittent-heating, visual drying defects （bow, crook, twist, check along grain and end check） were measured, and then statistical analyses were performed. It was found that the drying quality of small-diameter Birch lumbers could be improved with intermittent-heating, but the intermittent time should be prolonged. Prolonging intermittent time helped to weaken or even avoid wood distortion and drying checks. It wash＇ t helpful in avoiding crook. The drying quality of small-diameter Birch lumbers with all kinds of drying methods reached the second class of the Chinese National Standard. The drying quality reached the first class of the Chinese National Standard with the intermittent-heating in the area of visual wood defects.
The larch wood was treated by microwave irradiation under different radiant intensity and treating duration. The microwave-treated wood specimens together with the un-treated for comparison were impregnated by water i...
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The larch wood was treated by microwave irradiation under different radiant intensity and treating duration. The microwave-treated wood specimens together with the un-treated for comparison were impregnated by water in pressure vessel and then tested for permeability, mechanical properties and microstructure change by SEM to study the modification performance of microwave treatment on larch wood. The results showed that under suitable conditions of microwave treatment the permeability of larch wood was improved without noticeable decreasing of the modulus of rupture （MOR） and the modulus of elasticity （MOE）. The radial parenchyma and some pit membrane were ruptured, and tiny cracks were formed in the cell walls. The formation of tiny cracks in the cell walls serves as man-made channels of gas and liquid and this contribute to improve the permeability of the wood.
Wood is a kind of porous natural material with very poor electro-conductivity, and it has almost no function of electromagnetic shielding. The method of electroless nickel plating was used to produce wooden material w...
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Wood is a kind of porous natural material with very poor electro-conductivity, and it has almost no function of electromagnetic shielding. The method of electroless nickel plating was used to produce wooden material with electrical and effective electromagnetic shielding properties. Ni-P alloy layer was obtained on wood surface. The surface feature of plated wood veneer was observed by SEM and the surface composition and microstructure of the layer under different conditions were investigated by EDS and XRD respectively. Meanwhile, the relevant surface resistivity and electromagnetic shielding effectiveness were measured. Correlations of the phosphorous content in the layer to the structure of Ni-P alloy, electro-conductivity and electromagnetic shielding of plated veneers were discussed. SEM photos showed that the surface of electroless nickel plated veneers were covered with Ni-P alloy layer entirely, which made wood veneers more like metal. At the same time, the results showed that with the decreasing of the phosphorous content in the layer, the microstructure of Ni-P alloy layer transformed to be microcrystalline and electro-conductivity and electromagnetic shielding effectiveness were improved. When the phosphorous content was less than 2.37wt pct in the layer, the microstructure of Ni-P alloy layer was microcrystalline structure and its sur- face resistivity and electromagnetic shielding effectiveness were nearly 0.5Ω/□ and 55-60dB respectively.
Three kinds of composites （fiber/Polypropylene, fiber/Polyethelene, and fiber/Polystyrene） were made by using hot pressing process for substrate of floorboard and the properties of each kind of composites were teste...
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Three kinds of composites （fiber/Polypropylene, fiber/Polyethelene, and fiber/Polystyrene） were made by using hot pressing process for substrate of floorboard and the properties of each kind of composites were tested. MORs of PP/wood fiber, PS/fiber, and PE/fiber composites with coupling agent added were raised by 18.4%, 37.1%, and 42%. respectively, compared to those without coupling agent. Among the three kinds of fiber/plastic composites, fiber/PP composite has best mechanical properties, and it can meet quality standard of eligible grade product and come up to the excellent grade products of China when the coupling agent is added. The performance of composite made of PE/fiber or PS/fiber can exceed qualified product grade only with coupling agent added.
Hem-fir plywood were exposed to two brown rot fungi, Gloeophyllum trabeum and Postia placenta, and one white rot fungus, Trametes versicolor, to investigate the effect of fungal decay on mechanical properties of plywo...
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Hem-fir plywood were exposed to two brown rot fungi, Gloeophyllum trabeum and Postia placenta, and one white rot fungus, Trametes versicolor, to investigate the effect of fungal decay on mechanical properties of plywood. Results showed that modulus of rupture （MOR） and modulus of elasticity （MOE） of hem-fir plywood declined significantly by inoculating fungi, and weight loss of sample had a modest decrease. The fungi also made a greater effect on MOR than on MOE. Of three fungi, Postia placenta caused a most significant weight loss, and Gloeophyllum trabeum resulted in a largest flexural properties loss. Substantial declines in MOR and MOE of hem-fir plywood were also observed when the plywood samples were stored under wet conditions over 15 weeks, even in the absence of fungal attack.
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