Summary and meaning of words used in lecture :-

THINGS TO KNOW

-5 R principle

Reduce

Reuse

Recover

Recycle

Refuse

-Rayon is know as artificial silk

-Nylon is used for mountain ropes as it very strong

-Rayon is obtained from tree pulp but it is an artificial fiber as it is processed chemically

-Thermosetting plastics are made up from long chains of molecules that are cross-linked.. Once heated, thermosetting plastics can be molded, shaped and pressed into shapes. Once set they cannot be reheated since they are permanently set.

-Artificial fiber do not absorb water

-Polymers are  any of a class of natural or synthetic substances composed of very large molecules, called macromolecules, that are multiples of simpler chemical units called monomers