Liquid Crystal Polymer (Liquid Crystal Polymer), referred to as LCP. is a new type of high-performance engineering plastics developed in the early 80's
Overview
LCP is a new class of polymers with outstanding performance. LCP is a class of materials containing a wide range of.
a, solvatochromic liquid crystals: need to be processed in solution;
b, thermotropic liquid crystals: can be processed in the molten state.
Initially industrialized liquid crystal polymers are solvatochromic poly(p-phenylene terephthalamide) (Kevlar?) developed by DuPont in the United States. Since this type of polymer can only be processed in solution and cannot be melted, it can only be used as fibers and coatings. The following covers only thermotropic LCP.
LCP Appearance: beige (also white opaque solid powder);
LCP Density: 1.35-1.45g/cm?
Classification of heat resistance of liquid crystal resins (low, medium and high heat-resistant types)
Type Heat distortion temperature/°C ASTM classification Japanese classification Brand name example
Low heat-resistant <177 Type I Type III Vectra? A430, Rodrun? LC3000
Medium heat-resistant
177～243
Type IIType II Zenite? 6330, Vetra? A130, Novaccurate? E335G30, Sumikasuper? E7000, Rodrun? LC5000, Ueno LCP?1000
High Heat Resistance >243 Type III Type I Type I Xydar? 930, Zenite?6130 Vectra? C130, Ueno LCP?2000, Titan LCP? LG431, Novaccurate? E345G30
Representative Properties of Highly Heat-Resistant Liquid Crystal Polymers
Grade Xydar?
G-930 Titan?
LG431 Zenite?
7130 Zenite?
6130 Vectra?
E130i Vectra?
c130
Relative Density 1.60 1.63 1.66 1.67 1.61 1.62
Tensile strength / MPa 135 139 145 150 165 159
Bending Strength/MPa 172 170 174 170 221 214
Izod Notched Impact Strength/(J/m) 96 299 160 123 208 176
Heat Deflection Temperature (1.82 MPa)/°C 271 275 289 263 276 255
Two, LCP characteristics and applications
1, characteristics
a, LCP has self-reinforcing: with an exceptionally regular fibrous structure characteristics, and thus does not enhance the liquid crystal plastics can be achieved or even more than ordinary engineering plastics with a few dozen percent of glass fiber reinforced mechanical strength and its modulus level. If the glass fiber, carbon fiber and other enhancement, more far more than other engineering plastics.
b, liquid crystal polymers also have excellent thermal stability, heat resistance and chemical resistance, creep characteristics of most plastics, liquid crystal materials can be negligible, and wear-resistant, wear-resistant are excellent.
c, LCP's weather resistance, radiation resistance is good, with excellent flame retardancy, can extinguish the flame and no longer continue to burn. Its combustion level reaches UL94V-0 level.
d, LCP has excellent electrical insulation properties. Its dielectric strength is higher than general engineering plastics, good arc resistance. In continuous use temperature 200-300 ℃, its electrical properties are not affected. Intermittent use temperature up to 316 ℃ or so.
e, LCP has outstanding corrosion resistance, LCP products in the concentration of 90% acid and concentration of 50% alkali will not be eroded in the presence of industrial solvents, fuel oils, detergents and hot water, will not be dissolved after contact, and will not cause stress cracking.
2, applications
a, electrical and electronic is the main market for LCP: electrical and electronic surface assembly welding technology on the dimensional stability of the material and heat resistance has high requirements (can withstand the surface assembly technology used in the gas phase welding and infrared welding);
b, LCP: printed circuit boards, satellite electronic components, jet engine parts, automotive mechanical parts, medical aspects;
c, LCP added to high filler or alloy (PSF/PBT/PA):
as integrated circuit encapsulation materials,
instead of epoxy resin for the coil skeleton encapsulation materials;
for fiber optic cable connector sheath and high-strength components;
instead of ceramics for the chemical industry with the separation tower in the
Replacing ceramics as filler material in chemical separation towers.
Replaces glass fiber reinforced polysulfone and other plastics (panels on the exterior of spacecraft, braking systems on the exterior of automobiles).
LCP has been used in microwave oven containers, which can withstand high and low temperatures.LCP can also be made into printed circuit boards, electronic parts for artificial satellites, and jet engine parts: used in electrical, electronic and automotive mechanical parts or components; and also used in medical applications.
LCP can be added to high filler as an integrated circuit encapsulation material to replace the epoxy resin for the coil skeleton encapsulation material to replace the epoxy resin for the coil skeleton encapsulation material; for fiber optic cable connector sheath cover and high strength components; instead of ceramic for the chemical industry with the separation of the tower of the filler material, etc.. LCP can also be mixed with polysulfone, PBT, polyamide and other plastics **** made of alloys, high mechanical strength after molding parts to replace the glass fiber reinforced polysulfone and other plastics, not only to improve the mechanical strength properties, but also to improve the use of strength and chemical stability. LCP is currently being studied for use in astronauts external panels, automotive exterior braking system.
Three, LCP injection molding process
Since the performance and use of the modified level of difference is very large, its processing process variables are also very large, it should be adjusted accordingly to the following ranges:
1, drying: 140 ℃ ~ 140 ~ 150 ℃ / 5-7Hr
2, injection temperature: 260 ~ 300 ~ 410 ℃
3, Mold temperature: 100～100～240℃
Four, the main production companies
①Du Pont,
②Eastman,
③Solvay,
④Ticona,
⑤Mitsubishi Engineering Plastic Corporation,
⑥Sumitomo,
⑦Poly Plastics (a joint venture of Ticona and Nippon Daicel Chemical Corporation),
8 Toray,
in addition to Ueno Fine Chemicals and Unitika.
V, other understanding
Thermogenic LCP has all aromatic polyester and *** polyester structure. It also has a dense arrangement of straight-chain polymer chain structure, the formation of products with good unidirectional mechanical properties characteristics. Good high temperature performance (heat distortion temperature of 121 ~ 355 ℃), good radiation resistance, hydrolysis resistance, weather resistance, chemical resistance, inherent flame retardancy, low smoke generation, high dimensional stability, low moisture absorption, very low coefficient of linear expansion, high impact strength and rigidity (by the same weight comparison, the strength of the LCP is greater than steel, but the rigidity is only 15% of the steel).LCP can be resistant to acids, solvents and chemicals such as hydrocarbons, and has good barrier properties.
Liquid crystal aromatic polyester in the liquid crystal state because of its macromolecular chain is oriented, it has an exceptionally regular fiber-like structure, special performance, product strength is very high, and is not inferior to metals and ceramics. Tensile strength and flexural modulus can exceed the various thermoplastics developed in the past 10 years. Different monomers are used to produce liquid crystal polyesters with different performance, processability and price. The choice of filler and the amount of filler added also affect its performance.
Editorial
Two Link Control Protocol
LCP , short for Link Control Protocol
is a subset of the PPP protocol, in which the sender and the receiver in PPP communication determine those information necessary in data transmission by sending LCP packets.LCP checks the the identification of the linking device and decides whether to accept or reject it; determines the number of packet bytes that can be received in the transmission; and checks whether the configurations of the two parties match, and breaks the link if they do not. Data can only be realized for network communication if the LCP packet link is available. The LCP is responsible for the creation, maintenance, and termination of links between devices.
Editorial
Three International Student Organization AIESEC Terms
In AIESEC LCP stands for Local Committee President, or Chapter President. For example, LCP of AIESEC ZJU MoC is the president of the AIESEC chapter at Zhejiang University in mainland China.
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Four Electrical and Electronic Technology
Low-Cost Programmer (LCP) Low-Cost Programmer
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Five, financial terminology
Listing Company Planner (LCP) Business Listing Planner
Six, psychological terms
LCP life course-persistent offenders Lifetime persistent offenders. Defined by psychologist Terrie Moffitt, this group of people commit their antisocial behaviors under different conditions and scenarios. Typically, LCP offenders commit antisocial behavior throughout their lives.
Seven, the terminology of the cooling system
LCP Liquid Cold Plate Liquid Cold Plate, is based on the heat dissipation requirements of the higher effect of the equipment, instrumentation and the development of a new type of heat dissipation system, part of the patent in the Aavid Thermal Systems, Inc., the current liquid-cooled plate is divided into several types of substrate plate embedded tubes on the plate is a kind of a substrate on the sink, and then the upper and lower substrate merger. Brazing up is another program. Some products are very complex process, brazing temperature is also very high, be careful. In the face of increasing demand for heat dissipation, the materials and solutions used in liquid cooling panels have become more challenging.
VIII. Orthopedic terminology
1. Locking Compression Plate (LCP) is a new technique of internal fixation of fracture developed on the basis of power compression plate and point-contact plate.
2. It has the advantages of reliable fixation, low rate of nail withdrawal and few complications. At the same time of strong internal fixation, early functional exercise can be started, which can shorten the recovery period of the patient and maximize the restoration of the function of the joint.