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Wood modification definitions

Chemical reaction between reactive sites in wood components and a chemical reagent to form a non-polar bond between the two is defined as chemical modification. This definition excludes all impregnation treatments which do not form covalent linkages such as polymer inclusions, some coatings, heat treatments, etc. [Pg.304]

To calculate several of the cost items listed in Table 2.1, requires the depreciable and fixed capital costs. The depreciable capital cost is the capital required for equipment and its installation or modification in the process, and all the facilities required to operate the process. There is some variation in the definition of fixed capital cost. References [1-5], define the fixed capital as consisting of the depreciable capital cost, land cost, and site or land development cost. Woods [10], however, omits land cost and land development cost so that that the fixed capital cost equals the depreciable capital cost. We will adopt the first definition here. For now, assume that we know the depreciable capital cost. We will develop a procedure for its evaluation later. In Example 2.1 estimate the production cost using Table 2.1. [Pg.55]

A new, crystalline modification termed cellulose-x has been reported. It is obtained by treating cotton or wood pulp with concentrated hydrochloric acid at room temperature, or, in a particularly pure form, by the use of phosphoric acid at 50°. A definite interpretation of the structure cannot be given at present, but x-ray results indicate that a unit cell having the same dimensions as that of the high-temperature form of cellulose [cellulose IV (unit-cell dimensions a = 8.12, 6 = 10.3, c = 7.99 A. /8 = 90°) 2 is the most probable one, but having the pyranose rings of the central chain displaced by half a D-glucose residue with respect to the corner chains. The infrared spectrum lies between those of cellulose II and cellulose IV. [Pg.221]

In this chapter no distinction is made between a real chemical modification (acetylation), where covalent bonds between the reagent and the chemical constituents of wood are formed, and the impregnation modification, where monomers diffuse into the wooden cell wall and become polymerized there, like Hill suggested in his definitions (see above), because it was shown that DMDHEU and furfuryl alcohol not only swell the cell wall and polymerize there but also have the potential to form some covalent bonds. ... [Pg.330]


See other pages where Wood modification definitions is mentioned: [Pg.44]    [Pg.43]    [Pg.692]    [Pg.816]    [Pg.283]    [Pg.45]    [Pg.346]   


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