i need 500 words at least What are some limiting properties

i need 500 words at least

What are some limiting properties of plastics, and in what general area do they fall?

Solution

PROPERTIES OF PLASTIC MATERIALS

Following are the general properties of plastics.

1. STRENGTH

The plastics are sufficiently strong and can be used for load bearing structural members. The strength of plastics can further be increased by reinforcing them with various fibrous materials.

Plastic as structural material has not gained much popularity because of the following resins.

2. WEATHER RESISTANCE

The plastics, prepared from phenolic resins, are only good in resisting weather effects. Certain plastics are seriously affected by ultraviolet light.

3. FIRE RESISTANCE

Plastics, being organic in nature, are combustible. But the resistance to fire temperatue depends upon the plastic structure.

4. DURABILITY

Plastics generally possess sufficient durability, provided they offer sufficient surface hardness. Thermoplastic varieties are found to be attacked by termites and rodents.

5. DIMENSIONAL STABILITY

Plastics easily maintain its shape and do not go under plastic deformations.

6. CHEMICAL RESISTANCE

Plastics offer great resistance to moisture, chemicals and solvents. Many plastics are found to possess excellent corrosion resistance. Plastics are used to convey chemicals.

7. THERMAL RESISTANCE

The plastics have low thermal conductivity and therefore foamed or expanded varieties of plastics are used as thermal insulators.

8. WORKING CONDITIONS

All operations like drilling, sawing, punching, clamping etc are carried out easily on plastics, just like wood.

9. MOISTURE RESISTANCE

This property depends upon variety of plastics used, for example, cellulose plastics are considerably affected by the presence of moisture, whereas polyvinyl chloride plastics offer high resistance to moisture.

10. DUCTILITY

Plastics, generally, have low ductility and hence plastic structural members may fail without prior warning.

11. MISCELLANEOUS PROPERTIES

In addition to above properties, plastics have following qualities.