Liquid crystal polymer:-
LCP are a class of aromatic polyester polymer. They are extremely unreactive and inert and highly resistance to fire. Liquid crystal polymer, sometimes called super polymers, which were commercially introduced in 1984. Liquid crystal polymer comprises as diverse a family as the polyamide, but lacks their chemical homogeneity. Most commercial LCP are co polyester, co polyamide or polyester amide, although many other linkages are possible. LCP structure range from partially aliphatic to wholly aromatic with widely varying melting point, use temp. Chemical/solvent resistance, flammability, processabiliity and cost. While only the thermotropic. This mover polymeric family excels in thermal and mechanical performance. The uniqueness of these polymer steams from the extraordinary crystalline structure, exhibiting ordered domains even in liquid state. These are chain like micro molecules of rigid structure, mainly because of the existence of aromatic ring such as aromatic polyamide and polyester. These are two major groups Lyotropic and Thermotropic. In the former group the liquid crystals are formed in an appropriate solution; usually forming fiber. The thermotropic group consists of dry a melt. The first having the arrogation polyester. When a dissolved melt cool in region of proper transition temp. A liquid crystal phase is formed. It is characterized by high order that create turbidity. The most common form is the pneumatic. A bundle of parallel, long, rods like molecules. Additional cooling to the primary transition temp. Lead to solidification into a solid crystalline phase.
Because of their various properties, LCPs are useful for electrical and mechanical parts, food container and any other application requiring chemical inertness and high strength. LCP is particularly attractive for microwave frequency electronics due to low relative dielectric constants, low dissipation Factor & commercial ability of laminates packaging micro electromechanical system (MEMS) is another area that LCP has recently gained more attention. Liquid crystalline polymers are those polymers which undergo several phase changes between crystalline solid and liquid phases. These intermediate phases are called as ‘mesophases’. The molecular arrangement in these mesophases changes with the type of mesophases. These mesophases are more ordered than the liquid state but they flow like liquid state. LCP are available in both amorphous and crystalline grades. The amorphous types with their high strength to weight ratio are particularly useful for weight sensitive items in aerospace. Most LCP can be injection molded extruded, thermoformed and blow molded. LCP ease of processing gives them the ability to fill long, narrow molds, which makes them eminently suitable for such high performance parts as electronic connectors.
Liquid crystalline polymers (LCP’s) are those polymers which undergo several phase changes between crystalline solid and liquid phases. These intermediate phases are called as ‘mesophases’. The molecular arrangement in these mesophases changes with the type of mesophase. These mesophases are more ordered than the liquid state but they flow like liquid state the verity of ordering type of these mesophases is shown below. Liquid crystalline polymers (LCPs) are best thought of as being a separate, unique class of TPs. Their molecules are stiff, rodlike structures organized in large parallel arrays or domains in both the melted and solid states. These large, ordered domains provide LCPs with characteristics that are unique compared to those of the crystalline and amorphous plastics. Liquid crystal polymers (LCPs), sometimes called super polymers, which were commercially introduced in 1984, are called self-reinforcing plastics because of their densely packed fibrous polymer chains....
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