what are polyamides give eg and explain their formation?
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Polymer is defined as a chemical substance of a high molecular mass formed by the combination of a large number of simple molecules, called monomers. e.g.,
Polymerisation
The process by which the monomers get combined and transformed into polymers. is known as polymerisation.
Polymers are also called macromolecules due to their large size but converse is not always true. A macromolecule mayor may not contain monomer units, e.g., chlorophyll (C55H72O5N4Mg) is a macromolecule but not a polymer since there are no monomer units present so we can conclude that all polymers are macromolecules while all macromolecules may not be polymers in nature.
formation of polymer
When many molecules of a simple compound join together, the product is termed a polymer and the process polymerization. The simple compounds whose molecules join together to form the polymers are called monomers. The polymer is a chain of atoms, providing a backbone, to which atoms or groups of atoms are joined.This unit provides an overview of the main types of polymers characterised by how they are made, how their structures govern their general properties and how these properties can be refined by their formulation using a range of additives. Finally the unit summarises the range of processing techniques that can be used to convert polymers into a vast range of different products.Each of the other units in the Polymers section describes the manufacture, properties and uses of an individual polymer or group of polymers in more detail.
Polymers are large molecules, a type of macromolecule. Their chemical properties are similar to those of simple molecules. For example, if the polymer contains a carbon-carbon double bond, as in poly(but-1,3-diene), it will undergo additions reactions with, say hydrogen or bromine.
If it contains an aromatic ring, as in poly(phenylethene) (often known as polystyrene), it will undergo substitution reactions, say with nitric acid.
The major differences between smaller molecules and polymers lie not with their chemical properties but with their physical ones. Their larger sizes lead to much stronger intermolecular forces leading in turn to much higher melting points, and the characteristic properties of hardness and flexibility. These intermolecular forces are even stronger when the polymer chains pack together in a regular way as in HPDE (high density poly(ethene)) and have regions of crystallinity.
When heated, it melts and the crystallinity is lost. As it does not have a sharp melting point, the temperature at which this occurs is termed the melt transition temperature, Tm. Above this temperature, the polymer is amorphous.
Some polymers are hard and amorphous, having no regions of crystallinity, for example, poly(methyl 2-methylpropenoate). The temperature at which they become soft and pliable is termed the glass transition temperature
I hope it is helped you
Polymerisation
The process by which the monomers get combined and transformed into polymers. is known as polymerisation.
Polymers are also called macromolecules due to their large size but converse is not always true. A macromolecule mayor may not contain monomer units, e.g., chlorophyll (C55H72O5N4Mg) is a macromolecule but not a polymer since there are no monomer units present so we can conclude that all polymers are macromolecules while all macromolecules may not be polymers in nature.
formation of polymer
When many molecules of a simple compound join together, the product is termed a polymer and the process polymerization. The simple compounds whose molecules join together to form the polymers are called monomers. The polymer is a chain of atoms, providing a backbone, to which atoms or groups of atoms are joined.This unit provides an overview of the main types of polymers characterised by how they are made, how their structures govern their general properties and how these properties can be refined by their formulation using a range of additives. Finally the unit summarises the range of processing techniques that can be used to convert polymers into a vast range of different products.Each of the other units in the Polymers section describes the manufacture, properties and uses of an individual polymer or group of polymers in more detail.
Polymers are large molecules, a type of macromolecule. Their chemical properties are similar to those of simple molecules. For example, if the polymer contains a carbon-carbon double bond, as in poly(but-1,3-diene), it will undergo additions reactions with, say hydrogen or bromine.
If it contains an aromatic ring, as in poly(phenylethene) (often known as polystyrene), it will undergo substitution reactions, say with nitric acid.
The major differences between smaller molecules and polymers lie not with their chemical properties but with their physical ones. Their larger sizes lead to much stronger intermolecular forces leading in turn to much higher melting points, and the characteristic properties of hardness and flexibility. These intermolecular forces are even stronger when the polymer chains pack together in a regular way as in HPDE (high density poly(ethene)) and have regions of crystallinity.
When heated, it melts and the crystallinity is lost. As it does not have a sharp melting point, the temperature at which this occurs is termed the melt transition temperature, Tm. Above this temperature, the polymer is amorphous.
Some polymers are hard and amorphous, having no regions of crystallinity, for example, poly(methyl 2-methylpropenoate). The temperature at which they become soft and pliable is termed the glass transition temperature
I hope it is helped you
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