Have a look at your surroundings, everything that you will observe is made up of polymers. You can differentiate the polymers as natural polymers or synthetic polymers. Let us first have a quick look at the definition of polymers and then we will move on to classifying the natural and synthetic polymers. A polymer is defined as a large molecule which is formed by repetition of similar or different kinds of monomers (where the monomer is a small molecule which repeats itself to form a polymer). Moving on to classifying the types of polymers, we can broadly classify the polymers as:
- Natural polymers: The polymers which are obtained naturally are called natural polymers. A natural polymer has its origin in plants and animals. Starch, cellulose, proteins, natural rubber etc. are the examples of natural polymers. Let us briefly discuss these natural polymers:
- Starch: It is a polymer which forms the food reserve for all the plants. The monomer of starch is – D – glucose. When a polymer of starch is formed hundreds of – D – glucose molecules are joined through a linkage known as glycosidic linkage.
- Proteins: They are the building blocks for animals. Proteins are simply polypeptides and are formed when amino acids undergo polymerization. The structure of proteins can either be long chains or cross-linked. Hundreds of amino acids link together to form a protein molecule; the arrangement is highly organized.
- Rubber: Natural rubber is a polymer of 2- methylbuta-1, 3-diene. This polymer is popularly known as isoprene. Natural rubber is obtained from the rubber tree in the form of latex which is a milky juice of the rubber plant.
2. Synthetic polymers: The man-made polymers or the polymers which are synthesized in the laboratory are called synthetic polymers. Synthetic polymers find a large application in our daily life. Most of the things that we use are made up of synthetic polymers. Some of the typical examples of synthetic polymers are polyethylene, polyvinyl chloride, Bakelite, nylon, synthetic rubbers.
- Synthetic rubber: As we know that natural rubber is a polymer of 2- methylbuta-1, 3-diene but synthetic rubbers are either homopolymers of 1, 3- butadiene derivatives or copolymers of 1, 3- butadiene or its derivatives with another unsaturated monomer. In general, the synthetic polymer is any polymer which can be stretched to at least twice its length and regains its original shape after being stretched.
- Polyethylene (most commonly known as polyethylene): It is derived from unsaturated hydrocarbons. This synthetic polymer is used in making a large number of household articles. We have two types of synthetic plastic; that is low-density plastic which is chemically inert, robust and destitute in conducting electricity. Hence it is widely used in making toys, insulation wires and pipes. On the other hand, we have high-density polyethene which is also chemically inert. It is highly crystalline in nature. It is stiffer, harder and has greater tensile strength. It is used in the making of containers, pipes, and bottles.
So far we have seen the natural polymers, the difference between natural and synthetic polymers and the different types of synthetic polymers, rubber. The concepts are written for a quick revision if you want to know the further details kindly log on to byjus.com.