Wood species can be divided into two groups: hardwood and softwood. Softwoods are gymnosperm trees, while hardwoods are angiosperm trees. (Stenius 2000). The composition and structure of wood are a masterpiece of evolutionary design, which enable trees to grow tall and live for many years. The wood structure also enables the trees to survive for strong natural forces such as wind and gravity and the structure even provides for an efficient transport of water from the roots to the crown. Wood is a complex biocomposite built up of cells whose own building blocks, the wood polymers and their ideal composition, give rise to a superior weight-to-strength ratio for the wood material. Wood is essentially composed of cellulose, hemicelluloses, lignin, and extractives. Each of these components contributes to fiber properties, which ultimately impact product properties. In different wood species, however, their relative composition varies greatly, and also the chemical composition of wood varies quantitatively among tree species. According to the results, the lignin content and functional group were determined separately. In addition, the chemical structure was not similar between softwood and hardwood. Lignin is one of the important chemical constituents of lignocellulosic materials in wood and it is one of the most abundant biopolymers in nature. The physical …show more content…
It is synthesised in plants, algae and even in some animals, and it can also be synthesised by some bacteria. Cellulose, the major chemical component of fiber wall. Cellulose has a strong tendency to form intra- and inter-molecular hydrogen bonds by the hydroxyl groups on these linear cellulose chains, which stiffen the straight chain and promote aggregation into a crystalline structure and give cellulose a multitude of partially crystalline fiber structures and morphologies. Hemicelluloses are a group of heterogeneous polymers that play a supporting role in the
Shortleaf Pine (Pinus echinata) and Pulp and Lumber Production. Introduction Shortleaf pine (Pinus echinata) is commercially one of the four most important conifers in the southeastern United States. In fact, shortleaf pine has the widest range of all southern pines, spreading from Florida to New Jersey and from North Carolina to Oklahoma. Sidney Investments, a firm based in Dallas, Texas, is considering the purchase of a 360-acre parcel of forested land located in the Quachita Mountains of eastern Oklahoma. This land has been under timber production through one rotation to this point.
Redwoods were named for the color of their bark and heartwood. These trees have a high resistance to fungus and diseases due to the high tanin content in the wood. The dense, fibrous bark has an even higher content, and acts as an insulator from periodic fires which have plagued the countryside for centuries. Though these trees are immense, they have delicate foliage. The needles are narrow and sharp-pointed, and combine to form feathery sprays. The cones are an inch long and typically contain fourteen to twenty-four seeds. The older trees offspring sprout form their parents' roots in order to take advantage of the established root system.
Southern yellow pine has been popular for a long time and remains the preferred choice for building professionals. One can use southern yellow pine for building projects that are big and small. This wood is known for our nation’s most used and sustainably harvested wood resource. Southern yellow pine is a reliable product for any task such as building a deck or framing a house. It is one of the most useful kinds of wood considering it is a preferred choice from professional builders to do-it-yourselfers. This wood has many amazing benefits and is one of the most popular choices for outdoor decking. Southern yellow pine is the ideal choice of wood due to its strength & durability, broad availability, and cost efficient pricing.
Pinus lambertiana, commonly known as the sugar pine, is found on the west coast in the mountains of Nevada, California, Oregon and Mexico. The sugar pine is the tallest of all pines and has the longest cones of any conifer. It is very important in these regions for both economical purposes and the environment. (Habeck)
Junot Diaz’s “Wildwood” is a roller coaster of emotions. The author gives us a full view of the tempestuous relationship between Lola and her mother who discovers has breast cancer. Lola, a young girl who lives in New York with her brother and mother, early on we can see that Lola’s mother is particularly abusive and channels her frustrations towards her daughter. When her mother asks Lola to examine her breast for a lump, she has a premonition her life would change.
Barnett, J. R. (2004). Langenheim, J.H. Plant resins: chemistry, evolution, ecology and ethnobotany. Annals Of Botany, 93(6), 784-785. doi:10.1093/aob/mch103
STRUCTURE Kevlar Aramid Fiber is a synthetic (man-made) material known as Polymer. A polymer is a chain that is made up of many similar molecular groups, better known as ‘monomers’ that are bonded together. The ‘Monomers’ are made up of fourteen Carbon atoms, two Nitrogen atoms, two Oxygen atoms and ten Hydrogen atoms. A single Kevlar polymer chain could possibly have anywhere from one to five million monomers bonded together. A group of polymer chains can be organised together in a fiber.
The choice of wood also affects the violin's acoustical properties. Traditionally, violin makers used spruce and maple fr...
however, is a synthetic fiber. It is a polyamide whose molecular chains are formed by regularly
...ulose will be protected from anything that could potentially damage the cell otherwise. It also plays a part in helping cells keep their shape. Cell walls, along with cellulose, provide support for plants so that they can grow tall while maintaining their shape. The size of the plant will determine the amount of cellulose it will need, but all plants require some amount of it and make use of it constantly.
There are two popular ways of creating nylon for fiber applications. One, ¡°molecules with an acid (COOH) group on each end are reacted with molecules containing amine (NH©ü) groups on each end.¡± The nylon 6,6 is made in this fashion. The other common way of making nylon fibers is by polymerizing a compound containing an amine at one end and an acid at the other, to form a chain with reoccurring groups of (-NH-[CH©ü]n-CO-)x. If the x=5, the fiber is named nylon 6 (Nylon Fiber).
...icot stem. Label and sketch its parts. Take note of the position of the vascular bundle.
Taking wood from rainforests and old-growth forests is detrimental to the environment and society. However, it is possible for us to have sustainable wood if we make an effort.
present at all times but it must retain some of them. All plant life on Earth benefits from the ability of water to make a hydrogen bond with another substance of similar electronegative charge. Cellulose, the substance that makes up cell walls and paper products, is a hydrophilic substance ("water-loving"). It interacts with water but, unlike other hydrophilic substances, it will not dissolve in it. Cellulose can form strong hydrogen bonds with water molecules. This explains why a paper towel will "wick" water upwards when it comes in contact with it.
Bamboo is a widely used and it is an important material that is found typically anywhere in the world. It is generally found in rural areas as building materials in small tropical countries, this is due to bamboo having a high strength and low weight. Even though bamboo is referred to as a rural material, Architects and Engineers have begun to incorporating bamboo into buildings for strength and beauty. Bamboo is a versatile, renewable and sustainable resource in South Africa. It is easy to use bamboo in buildings, as simple tools can be used bend and cut it easily. Bamboo construction is also very resilient to wind, easy to build with and is even resistant to some natural disasters like earthquakes (if done and used properly). Bamboo is also used in landscape industry, interiors and as a temporary building material in construction.