Question

Explain the difference between (a) a synthetic and natural polymer. (b) a polyester and polyamide. (c) \(\alpha\) - and \(\beta\) -glucose.

Short answer

#Short_Answer# The main differences between synthetic and natural polymers are their origin and formation processes; synthetic polymers are man-made through chemical processes while natural polymers occur naturally in living organisms. Polyester and polyamide are different types of polymers with distinct chemical structures in their monomers and synthesis processes; polyesters are formed from organic acids and alcohols, while polyamides are formed from amines and carboxylic acids. \(\alpha\)- and \(\beta\)-glucose are isomeric forms of glucose that differ in the configuration at the anomeric carbon; \(\alpha\)-glucose has its -OH group in the axial position and is used in starch formation, while \(\beta\)-glucose has its -OH group in the equatorial position and is used in cellulose formation.

Step-by-step solution

Part (a): Synthetic and Natural Polymers

A polymer is a large molecule composed of many repeating units called monomers. They can be classified into two groups: synthetic and natural polymers. Synthetic polymers are man-made and created through chemical processes, whereas natural polymers occur in nature and are derived from living organisms. Synthetic polymers, such as plastics and synthetic rubber, are created by humans and can be engineered with specific properties tailored to their intended applications. Examples include polyethylene, polypropylene, and PVC. Natural polymers include materials such as proteins, cellulose, and DNA. These polymers are formed by biological processes within organisms and are essential to their structure and function.

Part (b): Polyester and Polyamide

Polyesters and polyamides are both types of polymers. They differ in the chemical structure of their monomers and the way they are synthesized. Polyesters are polymers that are formed by condensation polymerization between an organic acid (e.g., terephthalic acid) and an alcohol (e.g., ethylene glycol), with the elimination of a small molecule like water. A common example of polyester is polyethylene terephthalate (PET), which is widely used in the textile and packaging industries. Polyamides, on the other hand, are polymers formed by the condensation polymerization between an amine and a carboxylic acid or their derivatives (e.g., adipic acid and hexamethylenediamine for Nylon-6,6). This reaction results in the production of a polymer with amide linkages in the backbone, giving polyamides properties such as high strength and resistance to wear and chemicals. Examples of this are the nylons, which are commonly used in fabrics, ropes, and plastics.

Part (c): \(\alpha\) - and \(\beta\) -glucose

Glucose is a monosaccharide sugar that forms the building blocks of complex carbohydrates such as starch and cellulose. It exists in two isomeric forms, \(\alpha\)-glucose and \(\beta\)-glucose, which differ in the configuration at the anomeric carbon (C1). Isomers are molecules with the same chemical formula but different arrangements of atoms. In \(\alpha\)-glucose, the hydroxyl (-OH) group attached to the anomeric carbon is on the opposite side of the ring from the -CH2OH group, resulting in a trans configuration. Specifically, the -OH group on the anomeric carbon is in the axial position. In \(\beta\)-glucose, the hydroxyl (-OH) group attached to the anomeric carbon is on the same side of the ring as the -CH2OH group, resulting in a cis configuration. In this case, the -OH group on the anomeric carbon is in the equatorial position. The difference in configuration between these two isomers directly affects their properties and the way they are used in biological systems. \(\alpha\)-glucose is the building block of starch, a storage carbohydrate in plants, while \(\beta\)-glucose is the building block of cellulose, a structural carbohydrate providing support in plant cell walls.