The special plastic
Generally refers to a special function, can be used for aviation,
aerospace and other special applications in the field of plastic.
Such as fluorine plastic and silicone has outstanding resistance to
high temperature, self-lubricating, special functions, reinforced
plastic and foam has high strength,Water
slide cushioning properties, which belongs to the category of
special plastic plastic.
A reinforced plastics:
Reinforced plastic raw materials in the form can be divided into
granular ( such as calcium plastic reinforced plastic ), fibrous (
such as glass fiber or glass cloth reinforced plastic ), sheet (
such as mica reinforced plastics ) three. According to materials
can be divided into cloth reinforced plastic ( such as rags to
enhance or asbestos reinforced plastic ), inorganic mineral filled
plastics ( such as quartz and mica filled plastics ), fiber
reinforced plastic ( such as carbon fiber reinforced plastics )
three.
B foam:
Foam can be divided into rigid, semi rigid and soft foam three.
Rigid foam without pliability, compressive hardness large, only
reaches a certain value of stress to produce deformation, stress
relief can not be recovered; soft foam full flexibility,
compressive hardness is small, easy to deformation, stress relief
after the restitution, residual deformation; semi rigid foam
flexibility and other performance between hard with soft foam.
Two, normally characteristics classification
According to all kinds of plastic with different physicochemical
characteristics, can be divided into the plastics thermoset and
thermoplastic two types.
( 1) a thermoplastic plastic
Thermoplastic plastic ( Thermo plastics ): refers to the heated
melting, can flow into the mold cooling after molding, and heating
and melting the plastic; can be used for heating and cooling, make
its produce reversible changes ( liquid left / solid ), is called a
physical change. General purpose thermoplastic its continuous use
temperature below 100 DEG C, polyethylene, polyvinyl chloride,
polypropylene, polystyrene and known as the four general plastics.
Thermoplastic and hydrocarbons, containing polar vinyl, gene
engineering, cellulose and other types.
When heated,Plastic wood soft, hard when cooled, can be repeatedly softening and hardening and keep a definite shape. Soluble in a solvent, with fusible soluble properties. Thermoplastic plastics have excellent electrical insulation, particularly polytetrafluoroethylene ( PTFE ), polystyrene ( PS ), polyethylene ( PE ), polypropylene ( PP ) has a very low dielectric constant and dielectric loss, is suitable for high frequency and high voltage insulating material. Thermoplastic molding is easy processing, but heat resistance is low, easy to creep, the creep degree with load, environmental temperature, solvent, humidity and change.
In order to overcome the weakness of thermoplastic plastics, meet in space technology, the development of new energy and other areas of application needs, all countries in the development of melt molded heat-resistant resin, such as polyether ether ketone ( PEEK ), polyether sulfone ( PES ), poly ether sulfone ( PASU ), polyphenylene sulfide ( PPS ) etc.. Take them as the matrix resin for composite material has higher mechanical properties and resistance to chemical corrosion, hot forming and welding, interlayer shear strength ratio of epoxy resin.
As with polyether ether ketone as matrix resins and carbon fiber composites, fatigue resistance than epoxy / carbon fiber. Its good impact resistance, at room temperature with good creep resistance, good processability, from 240 to 270 DEG C in continuous use,Playground equipment is an ideal high temperature insulating material. Using polyethersulfone as matrix resins and carbon fiber composites at 200 degrees C has higher strength and hardness, at - 100 degrees C can still maintain good shock resistance; nontoxic, nonflammable, smoke at least, radiation resistance, it can be used for spacecraft expected key components, can also be molding processing a radar antenna cover.
Formaldehyde cross-linking plastic, including phenolic plastics amino plastics ( such as urea formaldehyde melamine formaldehyde etc. ). Plastic film other cross-linking plastic includes unsaturated polyester, epoxy resin, adjacent benzene two diallyl ester resin.
