1991 Fiscal Year Final Research Report Summary
Bonding between the woody fibers by the oxidative coupling of lignin model compounds with phenoloxidase.
| Project/Area Number |
02660179
|
|---|
| Research Category |
Grant-in-Aid for General Scientific Research (C)
|
| Allocation Type | Single-year Grants |
|---|
| Research Field |
林産学
|
|---|
| Research Institution | Kyushu University |
|---|
Principal Investigator |
YAMAGUCHI Haruhiko Faculty of Agriculture, Kyushu University, Assistant professor., 農学部, 助手 (10091381)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
SAKATA Isao Faculty of Agriculture, Kyushu University, Professor., 農学部, 教授 (10038169)
|
|---|
| Project Period (FY) |
1990 – 1991
|
| Keywords | phenoloxidase / woody fibers / phenols / dehydroxy polymerization / bonding / plybond strength / zutropfuerfahren / dialysis tube method |
|---|
| Research Abstract |
Peroxidase and laccase are the enzymes that catalyze the dehydrogenation of phenolic hydroxyl group and make up to phonoxy radicaI. For exampIe. when the Iaccase act to the isolated Iignin. although a part of Iignin change to low molecuIar-weight substancees. alarge portion of the lignin cross-linke to highe molecular-weight substanses. this polymerization reaction is the coupling-reaction between the radicals which are made up by the action of laccase. in the process of lignification. it is said that the I ignin-precursors, wich were 4 suppiied between cellulose and/or hemicellulose. polymerized by the actions of enzymes 5UCh Ss peroxidass. and then the bonding strength developed between the f ibers. In this study. we attempted that this dehydrogenation was made use the radicals were produced on the lign, in a woody fiber and/or on lignin-precursors. and then the woody fibers were bonded tgether through the radicalcoupling reaction. The peroxida5e waS PrOpared mom the bamboo shoots of
… More
Madake(Phyllastachys bambusoides Slob. et Zucc.). and laccase was prepared from the liquid-medium of Kawaratake(Coriolus versicolor IFO-8482). The dehydrogenation reactions were proceeded on the dialysis tube method with peroxidase and on the zut ropfuerfahren(the dropwise-additi on method)with laccase. In the results, Its. the optimum condit ions for the production of the dehydrogenative polymerization substance from the vanillic acid(UA-DHP)were was follows ; PH was about 6. reaction time was 24 hours. amount of veniIIic acid was more. activity of perox ida5e was about 15, 000 units. and the amount of 30% H202 WaS 8-1 nL. VA-DHP were precipitated and adsorbed on thermomechanical pull>(TMP). and then the vA-DHP-TMP complexes were used for the preparation or two-ply bonded paper. The plybonding strength(PS)of the paper were maximum on the same to the optimum condition of the VA-DHP production. The plybond strength were about 1.7 times of the strength of the plybonded paper to be made from the mixture of UA-DHP and TMP. It was thought that the coupling-bonds between the TMP and UA-DHP were formed when the vani Ilic acid were polymerized dehydrogenatively in the presence of TMP. and then the plybonding strength between the fibers was appeared. The production of dehydrogenative polymerization substance by the zutroptuerfahren6 with the laccase and the improvement of the bonding between the ribers by the activation of the woody fiber with the laccase. In the results, when the lignin in the TMP was activated by the function of laccase. and then the UA-DHP by the function of peroxidase were precipitated on the(ibors. the plybond strength were increased. The dehydrogenative polynerization reaction was applied to the manufacture of fiber board mom the double-disk refiner pulp(DDRP). In the results, when DDRP was treated by poxidase or laccase. the internal bonding strength(IB)and water-resistants of the boards were increased. In the laccase -treatment. the improvement of w Less
|
