Published | 2022-06-01 |
Platform | Udemy |
Number of Students | 3 |
Price | $19.99 |
Instructors |
Vinay Arya
|
Subjects |
Polyester
Natural polymers: The polymers which occur in nature i.e., which occur
either in plants or animals, are called natural polymers. For example,
natural rubber, proteins, cellulose, starch (polysaccharides), wood, silk and
nucleic acids are natural polymers.
Synthetic polymers: Synthetic polymers are man-made polymers. These
polymers are made in laboratories or factories. Typical examples of
synthetic polymers include polyethene, PVC, nylon, terylene, Teflon,
synthetic rubber, Bakelite and melamine.
Semi-synthetic polymers: Chemically modified natural polymers are
called semi-synthetic polymers. For example, nitrocellulose, cellulose
acetate etc. are termed semi-synthetic polymers. These polymers are also
called chemically modified natural polymers.
Linear chain polymers: The polymers m which the constituent monomers
link with each other to form a long straight chain are called linear chain
polymers, or straight chain polymers.
Linear polymers are well packed and thus have high densities, high tensile
strength and high melting points. For example, high-density polythene
(HDPE) is a linear chain polymer.
Branched chain polymers: The Polymers which have side-chains
attached to the linear chains consisting of monomers are called branched
chain polymers.
The branched chain polymers are irregularly packed and thus have lower
tensile strength, lower melting point and lower density. For example,
low-density polythene (LDPE) has lower density, lower melting point and
lower tensile strength than the linear high-density polythene (HDPE).