Title: Chemical modification of lignocellulosics
Author: Rowell, Roger M.;
Source: Proceedings, International Workshop on Frontiers of Surface Modification and Characterization of Lignocellulosic Fibers : Fiskebackskil, Sweden, May 30-31, 1996. [S.l. : s.n., 1996]
Publication Series: Miscellaneous Publication
Description: Agro-based resources, also referrered to as lignocellulosics, are resources that contain cellulose, hemicelluloses, and lignin. Lignocellulosics include wood, agricultural residues, water plants, grasses, and other plant substances. When considering lignocellulosics as possible engineering materials, there are several very basic concepts that must be considered. First, lignocellulosics are hygroscopic resources that were designed to perform, in nature, in a wet enviornment. Secondly, nature is programmed to recycle lignocellulosics in a timely way through biological, thermal, aqueous, photochemical, chemical, and mechanical degradations. In simple terms, nature builds a lignocellulosic from carbon dioxide and water and has all the tools to recycle it back to the starting chemicals. We harvest a green lignocellulosic (for example, a tree) and convert it into dry products, and nature, with its arsenal of degrading reactions, starts to reclaim it at its first opportunity). In order to produce lignocellulosic-based composite materials with a long service life, it is necessary to interfere with the natural degradation processes for as long as possible. This can be done in several ways. Traditional methods for decay resistance and fire retardancy, for example, are based on treating the product with toxic or corrosive chemicals which are effective in providing decay and fire resistance but can result in environmental concerns. There is another approach which is based on the premise that the properties of any resource are a result of the chemistry of components of that resource. In the case of lignocellulosics, cell wall polymers, extractives, and inorganics are the components that, if modified, would change the properties of the resource. In order to make property changes, you must first understand the chemistry of the components and the contributions each play in the properties of the resource. Following this understanding, you must then devise a way to modify what needs to be changed to get the desired change in property. Properties of lignocellulosics, such as dimensional instability, flammability, biodegradability, and degradation caused by acids, bases, and ultraviolet radiation are all a result of chemical degradation reactions which can be prevented or, at least, slowed down if the cell wall chemistry is altered.
Keywords: Lignocellulosics, chemical modification
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Rowell, Roger M. 1996. Chemical modification of lignocellulosics. Proceedings, International Workshop on Frontiers of Surface Modification and Characterization of Lignocellulosic Fibers : Fiskebackskil, Sweden, May 30-31, 1996. [S.l. : s.n., 1996]
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