We studied the effects of nanoparticles of organo-silane（NOS） compounds in the size range of20–80 nm on physical and mechanical properties in medium density fiberboard,and used NOS at four consumption levels of 0,5...We studied the effects of nanoparticles of organo-silane（NOS） compounds in the size range of20–80 nm on physical and mechanical properties in medium density fiberboard,and used NOS at four consumption levels of 0,50,100,and 150 g kg-1dry wood fibers.Density of all treatments was kept constant at 0.67 g cm-3.The water-repellent property of organo-silane significantly reduced water absorption（WA） and thickness swelling but mechanical properties declined due to the reduced proportion of wood-fiber as organo-silane was added to the matrix：the compression ratio of MDF panels and the integrity among wood-fibers both declined,resulting in reduced mechanical properties.We recommend use of 50 g of NOS/kg wood-fiber to improve WA and thickness swelling while retaining acceptable mechanical properties.展开更多
White rot fungi were optimized to cultivate highly active laccase. The characteristics of laccase incubated by continuous culture were compared with those of direct culture. The enzyme activity of laccase incubated by...White rot fungi were optimized to cultivate highly active laccase. The characteristics of laccase incubated by continuous culture were compared with those of direct culture. The enzyme activity of laccase incubated by continuous culture technology reached a higher value on the fifth day of the growth. The optimization incubation time of high activity laccase was the eleventh day. A large amount of highly active laccase can be obtained in a relatively short time by continuous culture to replace traditional laccase. After laccase treatment, the lignin composition of wood fibers were oxidation-catalyzed by laccase. The number of chemical-bonding points between the wood fibers was increased. The wood fibers treated by laccase were fabricated into boards and their mechanical properties improved with the laccase-incubation times. Compared with the fiberboards made from fibers that were pre-treated by laccase of incubation 5 days, the static bending strength of those that were pre-treated by laccase of incubation 11 days was increased by 18.95%, the elastic modulus was increased by 35.49%, and the internal bond strength was increased by 44.11%.展开更多
In the present study,described that preparation of oligoesterified wood fibre by theaddition reaction of the wood fibre with maleic anhydride(MA)and allyl glycidyl ether(AGE).Further,made of crosslinkable oligoesterif...In the present study,described that preparation of oligoesterified wood fibre by theaddition reaction of the wood fibre with maleic anhydride(MA)and allyl glycidyl ether(AGE).Further,made of crosslinkable oligoesterified fiber board at high temperature and underhigh pressues,accompanying plasticization of the wood fibre components.The product exhibitedthe high the modulus of repture in bending(MOR),good water repellency and dimesionalstability.展开更多
基金conducted as a joint research projectfinanced by SRTTU(Iran)UPM(Malaysia)
文摘We studied the effects of nanoparticles of organo-silane（NOS） compounds in the size range of20–80 nm on physical and mechanical properties in medium density fiberboard,and used NOS at four consumption levels of 0,50,100,and 150 g kg-1dry wood fibers.Density of all treatments was kept constant at 0.67 g cm-3.The water-repellent property of organo-silane significantly reduced water absorption（WA） and thickness swelling but mechanical properties declined due to the reduced proportion of wood-fiber as organo-silane was added to the matrix：the compression ratio of MDF panels and the integrity among wood-fibers both declined,resulting in reduced mechanical properties.We recommend use of 50 g of NOS/kg wood-fiber to improve WA and thickness swelling while retaining acceptable mechanical properties.
基金funded by National Natural Science Foundation of China(31170515)Specialized Research Fund for the Doctoral Program of Higher Education of China(20130062110012)Undergraduate Training Program for Innovation and Entrepreneurship of Northeast Forestry University,China(201410225157)
文摘White rot fungi were optimized to cultivate highly active laccase. The characteristics of laccase incubated by continuous culture were compared with those of direct culture. The enzyme activity of laccase incubated by continuous culture technology reached a higher value on the fifth day of the growth. The optimization incubation time of high activity laccase was the eleventh day. A large amount of highly active laccase can be obtained in a relatively short time by continuous culture to replace traditional laccase. After laccase treatment, the lignin composition of wood fibers were oxidation-catalyzed by laccase. The number of chemical-bonding points between the wood fibers was increased. The wood fibers treated by laccase were fabricated into boards and their mechanical properties improved with the laccase-incubation times. Compared with the fiberboards made from fibers that were pre-treated by laccase of incubation 5 days, the static bending strength of those that were pre-treated by laccase of incubation 11 days was increased by 18.95%, the elastic modulus was increased by 35.49%, and the internal bond strength was increased by 44.11%.
文摘In the present study,described that preparation of oligoesterified wood fibre by theaddition reaction of the wood fibre with maleic anhydride(MA)and allyl glycidyl ether(AGE).Further,made of crosslinkable oligoesterified fiber board at high temperature and underhigh pressues,accompanying plasticization of the wood fibre components.The product exhibitedthe high the modulus of repture in bending(MOR),good water repellency and dimesionalstability.
