WOOD is a material orthotropic found as primary content for the trunk of a tree. The trees are characterized by growing each year and logs that are composed of fibers of cellulose united with lignin. Plants that do not produce wood are known as herbaceous .
Once cut and dried, the wood is used for many applications.
Manufacture of pulp or pasta, raw material formaking role .
Feed the fire referred to as firewood is one of the simplest forms of biomass .
Structure of the wood
* Outer bark : is the outermost layer of the tree. It consists of cells of the same tree. This layer provides protection against agents atmospheric.
* Cambium : is the layer that follows the bark and gives rise to other two layers: layerinside or layer of xylem , to form wood, and a layer outside or layer of phloem which is part of the cortex.
* Sapwood : is the wood of more recent formation and for her travel most of the compounds of the sap . The cells carry the lifeblood, which is a sugary substance that some insects can feed. It is a more white layer because there travels more sap than for the rest of the wood.
*Heartwood (or heart): is the hard and consistent wood. It is formed by physiologically inactive cells and is located in the center of the tree. It is darker than sapwood and sap no longer flows through it.
* Vegetable marrow : is the central area of the trunk, which has low resistance, so is generally not used.
Composition of the wood
In media compositionis composed of 50% of carbon (C), 42% of oxygen (Or), 6% of hydrogen (H) and 2% of rest of nitrogen (N) and other elements.
The main components of the wood are the cellulose , a polysaccharide which is about half of the total material, the lignin (about 25%), which is a polymer resulting of the Union of several acids and alcohols phenylpropyl and provides hardness and protection, and thehemicellulose (about 25 per cent) whose function is to act as a Union of the fibers. There are other minority components as resins, wax, fats and other substances.
It is a structural polysaccharide consisting of glucose that is part of the wall of plant cells. Its empirical formula is (C6H5or10)n, with the minimum value of n = 200.
Its functions are the serve of our endurance to the plantand give a plant protection. It is very resistant to chemical agents, insoluble in all solvents and also impervious to air dry, its temperature of chipping under pressure of a bar are approximately 232,2 ° C.
Links for hydrogen between contiguous chains of cellulose.
Cellulose is a structural polysaccharide in the plants since it forms...