Thermosets and Elastomers

General:

Thermosets and Elastomers are man-made, synthetic and organic materials. Organic compounds consist of a base of carbon.

Properties:
Plastics as a material have been made ​​by a big name for its versatility in the art.

Some of the features are:

  • hard
  • fixed
  • spring return
  • soft
  • elastic
  • malleable
  • castable
  • weldable

 

Applications:
All plastics have certain characteristics that determine their use of the area.

Plastics also have properties that limit their applications.

  • Low thermal resistance
  • Some of flammable
  • Few plastics possess high strength
  • In part, not resistant to solvents


The variety of plastics is so large that can be found for almost all applications of the right one.

Manufacturing and construction:

The manufacture of plastics followed in many complicated chemical processes. The two most important sub-steps are synthesis and polymerization. From a raw material by synthesizing an intermediate is generated. This comes from individual molecules that are composed of a few atoms. The raw materials are called monomers. By a further chemical process, polymerization, the monomer molecules are stored together on many-jointed macromolecules. Monomers to produce, instead of the polymerization, the chemical steps polycondensation and polyaddition be used.

Raw materials and intermediate products:

Raw materials for plastics production are natural substances, such as cellulose, coal, petroleum and natural gas. In any case these are compounds of carbon (C) and hydrogen (H2). Also oxygen (02), nitrogen (N2) and sulfur (S) may be involved. The group of silicones as a main element silicon.
Besides natural gas, crude oil is the main raw material (feedstock) for the production of plastics.

Download
Raw materials and intermediate products.
JPG Bild 592.6 KB

Thermosets:

Source:http://www.billion.fr/-rubrique166-
Source:http://www.billion.fr/-rubrique166-

Production of thermosets:
Thermosets are often produced by polycondensation.
Polycondensation of two monomer molecules with the separation of water

After curing, they can not change their shape.

Structure of thermosets:

  • Closely linked macromolecules
  • At room temperature and harsh
  • Change their mechanical properties when heated only slightly
  • In hot, they decompose without melt before.
  • To mechanical impact react with tears or cracks.

Application:

  • Hood applications (water pump housings, pistons, pulleys, manifolds, etc.)
  • Helmets, like the fire helmet
  • Cable support systems
  • Performance and circuit breakers
  • Car body parts
  • Reflectors (headlights)
  • Household (iron heat shield, pot handles and oven door handles)

Elastomers:

Source:http://www.isgatec.com/de/seminare/oberflaechenveredelung/index.php
Source:http://www.isgatec.com/de/seminare/oberflaechenveredelung/index.php
Production of elastomers:
The main raw material is natural rubber or synthetic rubber.
The original rubber is vulcanized under heat.
The rubber goes into a rubbery state.

Structure of elastomers:

  • Loosely crosslinked macromolecules
  • By elastic force by several hundred percent.
  • This property is called elastic.
  • Limited formability warm.

Application:

  • They are not soft when heated and are not soluble in most solvents.
  • Therefore they are used for hygienic articles or chemicals gloves.
  • The rubber compound of the tires is also an elastomer.
  • O-rings, damping elements, sealing elements and hydraulic hoses or gasoline

Additional elastomers:

  • Thermoplastic elastomers (elastoplasts) 
    • when heated deformable
    • weldable
  • Liquid Crystalline Elastomers
  • Magnetorheological elastomers
    • By electromagnetic field, the molecules change, both in the shape and in length.

Determination of plastics:

How can I find out what plastic was used.

  • Appearance
  • Field of application
  • Surface texture
  • Mechanical properties (hard, brittle, rubbery, etc.)
  • Heating
  • Burning behavior

Kommentar schreiben

Kommentare: 0