Question

what is the difference between an amorphous, an oriented, and a crystalline plastics?

Answer 1

Amorphous plastics have no defined shape, can easily alter the shape.amorphous polymer soften gradually as temperature rises.these type of polymers do not have patterned order between molecules, and molecular structure doesnot exists in crystallization. for example PVC and atactic polymers, the presence of polar group can restrict the crystallization in this type of polymers.These are more transparent,and these have lower dimensional stability , lower shrinkage upon cooling.

crystalline polymers consists of highly organized and tightly packed molecules or the polymer molecules lineup regularly to give crystalline structure.this type of polymers have high density and high melting points.force of attraction of polymer molecules are strong.these have high resistance, greater shrinkage on coooling, high dimensional stability and lower creep.for example nylon, polyamide.

oriented polymer can sustain a machnical load depend upon the strength of covalet bonds and the forces between the molecules.orientation of polymer means, when a substantial fraction of polymer chains can be alligned in the load bearing direction, a large portion of the load can be transmitted to the main chian covalent bonds.this orientation of polymer .example:fibre.