Polymers and macromolecules - class-VII

The compounds that are used to make synthetic fibres come from raw materials such as petroleum-based chemicals or petrochemicals. 

Synthetic fibres are cheaper than natural fibres. The synthetic fibers are cheap because they are built from cheap raw materials and produced very efficiently; for example, nylon and polyester are mostly built from oil by-products and are efficiently produced in huge amounts. 

Synthetic fibers are prepared by chemicals, this chemicals are available in cheap prize so that synthetic fibers can be produced in large quantity. Natural fibers are obtain from the natural sources which are present in the limited quantity.

Aramid fibers are a class of heat-resistant and strong synthetic fibers. They are used in aerospace and military applications, for ballistic-rated body armor fabric and ballistic composites, in bicycle tires, and as an asbestos substitute. 

Synthetic fibres melts on heating.

Synthetic fibers such as rayon, polyester melt on heating. Therefore it is not safe while cooking. It the clothes catch fire it can be disastrous. Cotton cloth is best and safe to wear in such conditions.

Polycot is obtained by mixing polyester and cotton.

Option (D) is correct as;  Synthetic fibres catch fire easily and on heating synthetic fibres melt and stick to the body of the person wearing it.

 Jute is a long, soft, shiny vegetable fibre that can be spun into coarse, strong threads. It is produced from plants in the genus Corchorus, family Malvaceae. 

Jute is one of the cheapest natural fibers, and is second only to cotton in amount produced and variety of uses. Jute fibres are composed primarily of the plant materials, cellulose (major component of plant fibre) and lignin (major components wood fibre). It is thus a ligno-cellulosic fibre that is partially a textile fibre and partially wood. It falls into the bast fibre category (fibre collected from bast or skin of the plant) along with Kenaf, Industrial Hemp, Flax (Linen), Ramie, etc. 

Blended fibers are manufactured from a mixture of two or more different type of fibers. Mixing fibers allows manufactures to form new textile yarns with distinct advantages. Each fiber retains its separate set of physical and aesthetic characteristics inherent in its design but the fabric acquires new characteristics depending on the type and percent of fibers used. Blends utilize the advantages of all the fibers to counteract the disadvantages of a single fiber. Synthetic fibers can be blended with natural fibers to create a material that is stronger, but more comfortable.

Synthetic fabrics are textiles made from man-made rather than natural fibers. Synthetic (chemically produced) fibres are made by joining monomers into polymers, through a process called polymerization. A synthetic fibre, when magnified, looks like plastic spun together. Polymerization is the formation of macromolecules through repetition of basic units. Initially, the various components are solids and first must be converted to a liquid state to be extruded into fibers. The materials are chemically converted, dissolved, or melted, turning into a thick liquid.

Clothes made of pure synthetic fibres are garishly lustrous. Synthetic fibres melt before burning. So clothes made of such fibres stick to the skin when in contact with a flame, causing burns. Therefore, they should not be worn in the kitchen or while setting off fireworks. 

Cellulose (say, cotton) is dissolved in a mixture of sodium hydroxide (NaOH) and carbon disulphide ($CS _2$, a solvent). A viscous liquid (i.e., a liquid which cannot flow freely) called viscose is obtained. The viscose is then forced through spinnerets (which have small holes) into an acid bath, and filaments of viscose rayon are obtained.

Plastic follow all the 4R principles: Reduce, reuse, recycle, restore.

Artificial fibres is other name given to synthetic fibres. Examples of synthetic fibres are nylon, PVC, polyester, etc.

Bakelite is the first synthetic thermosetting plastics.

Acrylic is a man-made fiber it resembles wool and hence it is also known as artificial wool or synthetic wool.  In commercial use acrylic is cheaper than natural wool and can be dyed in various colours.

The fabrics that are produced entirely from chemicals are known as synthetic fabrics. Examples of synthetic fabrics are nylon, polyester, rayon, and acrylic

Synthetic fibres are not obtained from natural resource but it is manufactured in a laboratory using petrochemicals. Synthetic fabrics are textiles made from man-made rather than natural fibres. Examples of synthetic fabrics include polyester, acrylic, nylon, rayon, acetate, spandex, latex, Orlon and kevlar. Synthetic (chemically produced) fabrics are made by joining monomers into polymers, through a process called polymerisation. 

Acrylic is a synthetic fiber that mimics the properties of wool, making it a popular choice for artificial woollen garments.

The given statement is true.

Natural polymer-These polymers are found in plants and animals. Examples are proteins, cellulose, starch, resins rubber and rayon.

Polystyrene is made of styrene monomer which is a synthetic polymer. The monomer is a liquid petrochemical.

NATURAL  POLYMER  -  The polymers found in nature, i.e., from plants & animals are known as natural polymers.
RAYON - Rayon is classified as semisynthetic polymer, as it is manufactured from naturally occuring polymers. It is purified from cellulose.
NYLON - $6$  -  Nylon - $6$ is a synthetic polymer, obtained by heating caprolactum with water at high temp.
DACRON  -  It is also a synthetic polymer. It is formed by interaction of ethylene glycol & terephthalic acid.
PROTEINS  -  Proteins are large macromolecules, containing one or more chains of amino acids. They are held together by peptide bonds. Amino acids are found in living organisms. Hence, they are natural polymer.

Cellulose is an organic compound consisting of a linear chain of several hundred to over ten thousand $\beta$ (1 $\rightarrow$4) linked $D - glucose$ units.

The S in Buna- S refers to styrene. Buna stands for butadiene and Na for sodium.
Buna-S refers to styrene Butadiene Rubber (SBR). It is copolymer of buta-1,3-diene and styrene in the ratio of 3:1 in the presence of sodium.

Among the following, cellulose is a natural polymer. It is a polysaccharide.

Natural polymers occur in nature and can be extracted. 

Acrylic fibers are synthetic fibers made from a polymer (polyacrylonitrile) with an average molecular weight of approx 100,000, about 1900 monomer units. 

There are two types of polymers: synthetic and natural. 

Polyisoprene is a natural polymer made of isoprene as the monomeric unit.

Acetate rayon is a organic polymer formed by acetylation of all remaining -OH's of linear cellulose chain. It is a synthetic filament, yarn, or fabric composed of a derivative of the acetic ester of cellulose.

Cellulose is not a synthetic polymer. It is a natural polymer.
It is a polysacchardie having molecular formula $(C _6H _{10}O _5) _n$. It has linear chain of $\beta(1\rightarrow 4)$ linked D-glucose units. There are several hundred to many thousands of such units in a chain.  Cellulose is an important structural component of  in the primary cell wall of green plants, many forms of algae and the oomycetes.