What is isotropic pitch?
What is isotropic pitch?
Pitch is a viscoelastic material that is composed of aromatic hydrocarbons. Pitch is isotropic, but can be made anisotropic through the use of heat treatments. However, the most important in carbon fiber production is mesophase pitch due to the ability to melt spin anisotropic mesophase pitch without filament breakage.
What is pitch precursor?
Pitch Precursors Pitch is a polycyclic aromatic hydrocarbon obtained from petroleum asphalt, polyvinyl chloride or coal tar.
What is meant by mesophase in chemistry?
In chemistry and chemical physics, a mesophase is a state of matter intermediate between liquid and solid. Gelatin is a common example of a partially ordered structure in a mesophase. Further, biological structures such as the lipid bilayers of cell membranes are examples of mesophases.
What can carbon fiber be used for?
Carbon fiber — sometimes known as graphite fiber — is a strong, stiff, lightweight material that has the potential to replace steel and is popularly used in specialized, high-performance products like aircrafts, racecars and sporting equipment.
What do you understand by carbonisation?
2.1 Carbonisation Carbonisation is the term used when complex carbonaceous substances such as wood or agricultural residues are broken down by heating into elemental carbon and chemical compounds which may also contain some carbon in their chemical structure.
What was pitch used for?
Pitch was traditionally used to help caulk the seams of wooden sailing vessels (see shipbuilding), and to coat earthenware vessels for the preservation of wine. Pitch may also be used to waterproof wooden containers and in the making of torches.
What is the composition of carbon Fibre?
Carbon fiber is a material consisting of fibers around 5–10 μm in diameter and composed mostly of carbon atoms. Carbon atoms are bonded together in crystals that are aligned parallel to the long axis of the fiber. It is this crystal alignment that gives the fiber high strength-to-volume ratio.
What is carbon Fibre used for?
What are the types of mesophase of liquid crystal?
In calamitic mesogens, there are three types of mesophases namely the nematic, cholesteric and smectic originally classified by Friedel [7] based on the degree of positional and orientational order. The discovery of new phases in liquid crystals turns to be often associated with an increase of complexity.
What are nematic liquid crystals?
A nematic liquid crystal is a transparent or translucent liquid that causes the polarization (that is, the focusing in a plane) of light waves to change as the waves pass through the liquid. When a voltage is applied, an electric field is produced in the liquid, affecting the orientation of the molecule s.
