For decades, together with many countries in the world, China has done a lot of work on the modification of wood, especially the modification of artificial fast-growing and high-yield wood. As one of the more effective ways of wood modification, wood and ceramic materials have become a hot spot in recent research. Wood's microstructure and characteristics Wood is an anisotropic, porous, fibrous organic polymer compound that contains cellulose, hemicellulose, and lignin.
Cellulose is the main component of the wood cell wall, and its properties play an important role in the physical and chemical properties of the wood. Since cellulose and hemicellulose are polysaccharides with grape pond units, and each glucose unit has three digestive tears, it is an active functional group. Therefore, many ways to modify wood are aimed at cellulose. Based on. The fibers of the wood are mainly distributed along the longitudinal direction of the kernel. Along this direction, they mainly exist in the form of bonds and one bond. The bond energy of the above two chemical bonds is very high, so the fracture is very difficult, which is why the wood resists in the longitudinal direction. Because of the very high tensile and compressive strength, only a small number of fibers are distributed in this direction in the radial direction. The main chemical bonds are hydrogen bonds and van der Waals forces. Therefore, the wood has very low compressive and shear strength in this direction. It is easy to crack along the longitudinal direction.
Wood anisotropy is due to the distribution of wood fibers in a certain direction. In a sense, the physical and chemical properties of cellulose determine the macroscopic physical and chemical properties of wood. Wood science, wood chemistry, and cellulose chemistry are the basis for wood modification, and they are also an important theoretical basis for the compounding of wood and ceramic materials.
Microstructures of Inorganic Ceramics Ceramics is a general term for a wide range of inorganic non-metallic materials with a wide variety of types. It is defined in both generalized and narrow sense. The first refers to narrowly defined kiln products that require high temperature processing and sintering, such as architectural ceramics, daily-use ceramics, and special ceramics. Superconducting materials are also a kind of ceramics. Second, they refer to the general term for silicate products. Cements and glass are also classified as foreign countries. Ceramics, ceramics here is a broad concept. With a typical silicon tetrahedron as the structural unit, it extends infinitely to form a three-dimensional network structure with some other metal or non-metal elements interspersed, resulting in variation and defects in the network structure and forming the microstructure characteristics of general ceramic materials. . This is also the main reason why inorganic silicate materials such as ceramics, cement, glass, and rock are relatively stable, high in hardness, high in compressive strength, and can withstand high temperatures of several hundred or more without melting and decomposition.
The above characteristics of ceramic materials are not possessed by wood, but it also has its inherent defects, namely poor toughness and easy to break, which is exactly the advantage of wood. The two elements are combined with each other and produce many little-known Pang has peculiar organosilicides, which have only been known to people in recent decades and have been rapidly applied and promoted, such as non-stick anti-stick coatings, silicone water repellants, silicone oils, and silicones. External wall paint and so on.
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