Give classification of plastics, Electrical Engineering

Assignment Help:

Give classification of plastics and also the differences between them.

Plastics are materials (containing carbon as common element) that have organic substances of high molecular weight and are able of being formed in required shape throughout or after their manufacture. The organic substances are termed as resins polymers and are derived from natural gas and petroleum. The polymers are mixed along with other materials to change their properties. There are two kinds of plastics: thermoplastics, thermosettings.

Thermoplastic materials:-

The properties of these plastic materials do not change considerably if they are melted and then cooled and solidify. They are deformable at higher temperature.

Thermoplastic materials: The properties of such plastic materials do not change considerably when they are melted and after that cooled and solidify. They can be repeatedly dissolved or melted in various solvents. They are additional elastic, less brittle and do not lose elasticity while subjected to prolonged heating. They are less apt to age thermally. Again and again they can be remoulded in any shape after heating. Several of them possess extraordinary high insulating properties and they are water repellent. They are polymers of linear structure that is their molecules are elongated and are like thread. This, kind of structure is soluble, fusible, highly plastic, able of forming thin flexible threads as well as films. Illustrations are Polytetra Flouroethylene (P.T.F.E. or Teflon) and Polyvinyl Chloride (P.V.C.)

Thermosetting Plastic Materials: They are either softening or originally soft upon heating but harden permanently on more heating and they cannot be resoftened when they have set and hardened.

They undergo huge changes while subjected to high temperatures for rather sometimes. They are called as baked and no longer can melt or be dissolved. They are more brittle, less elastic and lose their elasticity while subjected to prolonged heating. Therefore they cannot be remoulded in various shapes once they are hardened and set. They are used, while insulation is to withstand high temperatures without losing or melting its shape and also mechanical strength. Thermosetting plastic substances are space-polymers and the molecules branch off in different directions throughout polymerisation. Such structure makes them extremely rigid, fusible, poorly soluble, and enable of forming elastic films and threads. Examples are Phenol formaldehyde (i.e. Bakelite), Epoxy resins.


Related Discussions:- Give classification of plastics

SINGLE-PHASE INDUCTION MOTORS MOTORS, HOW DOES SINGLE PHASE INDUCTION MOTOR...

HOW DOES SINGLE PHASE INDUCTION MOTORS DEVELOP A STARTING TORQUE ?

Torque angle, describe torque angle in ships electrical propulsion system

describe torque angle in ships electrical propulsion system

What is the significance of negative voltage, Q. What is the significance o...

Q. What is the significance of giving a negative voltage to the gate higher than that of the source?  This is done to reach the saturation at a lower of level of V DS .  The re

Role of consumers in distribution reform, Role of Consumers in Distribution...

Role of Consumers in Distribution Reform In the reforms procedure, mandatory metering for all consumers is being implemented.  Consumers should implement this measure. Public

FET, shockely equation?

shockely equation?

Find out form factor and peak factor, Find out Form factor and Peak factor:...

Find out Form factor and Peak factor: For the output of full wave rectifier, find out (a) RMS value, (b) Average value, (c) Form factor, and (d) Peak factor. S

Speed control of three phase induction motors , Speed  Control of Three  ...

Speed  Control of Three  Phase Induction Motors Three  phase  induction motors are invariably used in the application where in speed in  required to be  constant  or adjustabl

Explain working of electrically erasable programmable rom, Q. Working of El...

Q. Working of Electrically erasable programmable rom EEPROM is used for remote-area applications. The device is provided with special pins which, when activated electrically, a

Compute the maximum flux passing through the coil, Q. The 50-turn coil in t...

Q. The 50-turn coil in the configuration of Figure is rotated at a constant speed of 300 r/min. The axis of rotation is perpendicular to a uniform magnetic flux density of 0.1 T. T

Show the force exerted on each is about one million tons, Q. Consider two 1...

Q. Consider two 1-C charges separated by 1min free space. Show that the force exerted on each is about one million tons.

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd