The Basics of Polymers
Polymers are large molecules that are composed of repeated subunits known as monomers. They are categorized into three main categories, namely natural polymers, synthetic polymers, and semi-synthetic polymers. Natural polymers are naturally occurring polymers like silk, wool, and DNA. Synthetic polymers are artificially made polymers like plastics, nylon, and Teflon. Semi-synthetic polymers are made by combining natural polymers with synthetic polymers. In this article, we will discuss which of the following is not a semi-synthetic polymer.
What are Semi-Synthetic Polymers?
Semi-synthetic polymers are made by modifying the natural polymers using synthetic chemicals. The natural polymers are chemically modified by adding synthetic monomers to them. This modification enhances the properties of the natural polymers or imparts new properties to them. The semi-synthetic polymers have characteristics that are intermediate between those of natural and synthetic polymers.
Examples of Semi-Synthetic Polymers
Some examples of semi-synthetic polymers are cellulose acetate, rayon, and cellulose nitrate. Cellulose acetate is made by treating cellulose with acetic anhydride. It is used in the production of photographic films, eyeglass frames, and cigarette filters. Rayon is made by treating cellulose with carbon disulfide. It is used in the production of clothing, upholstery, and surgical dressings. Cellulose nitrate is made by treating cellulose with nitric acid. It is used in the production of lacquers, explosives, and celluloid.
Which of the Following is Not a Semi-Synthetic Polymer?
The answer to this question is natural rubber. Natural rubber is a natural polymer that is obtained from the latex of rubber trees. It is composed of isoprene monomers. Natural rubber is not a semi-synthetic polymer because it is not chemically modified using synthetic chemicals. However, natural rubber can be modified using various chemical processes to enhance its properties.
The Properties of Natural Rubber
Natural rubber has unique properties like high elasticity, good resistance to wear and tear, and low compression set. It is used in the production of various products like tires, gloves, footwear, and adhesives. Natural rubber is also used in the production of latex foam, which is used in mattresses, pillows, and cushions.
The Modification of Natural Rubber
Natural rubber can be modified using various chemical processes like vulcanization, epoxidation, and crosslinking. Vulcanization is a process in which natural rubber is treated with sulfur to improve its elasticity, strength, and resistance to heat and aging. Epoxidation is a process in which natural rubber is treated with an epoxide to enhance its adhesion and resistance to solvents. Crosslinking is a process in which natural rubber is treated with a crosslinking agent to improve its properties like heat resistance and chemical resistance.
The Advantages of Semi-Synthetic Polymers
Semi-synthetic polymers have various advantages like improved properties, reduced cost, and easy availability. They are used in various applications like textiles, packaging, and construction. Semi-synthetic polymers are also eco-friendly because they are made by combining natural and synthetic polymers.
The Conclusion
In conclusion, natural rubber is not a semi-synthetic polymer because it is not chemically modified using synthetic chemicals. Semi-synthetic polymers are made by modifying natural polymers using synthetic chemicals. Some examples of semi-synthetic polymers are cellulose acetate, rayon, and cellulose nitrate. Semi-synthetic polymers have various advantages like improved properties, reduced cost, and easy availability.