AQA Chemistry A-level 3.3.12 Polymerisation PDF
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This document provides detailed notes on polymerisation, focusing on condensation polymers, including polyamides, polyesters, and polypeptides. It also covers hydrolysis and disposal methods for these polymers.
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AQA Chemistry A-level 3.3.12: Polymerisation Detailed Notes This work by PMT Education is licensed under https://bit.ly/pmt-cc https://bit.ly/pmt-edu-cc CC BY-NC-ND 4.0...
AQA Chemistry A-level 3.3.12: Polymerisation Detailed Notes This work by PMT Education is licensed under https://bit.ly/pmt-cc https://bit.ly/pmt-edu-cc CC BY-NC-ND 4.0 https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc 3.3.12.1 - Condensation Polymers Condensation polymers form when a water molecule is removed from the species of a reaction. There are three main types of condensation polymers. Polyamides These are formed in a reaction between dicarboxylic acid and a diamine. A molecule of water is removed, leaving an amide linkage. Example: -CONH- is the amide linkage. Examples of polyamides include nylon-6,6 made from hexamethylenediamine and hexanedioic acid. Example: https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc Kevlar is another common polyamide made from 1,4-benzenedicarboxylic acid and 1,4-benzenediamine. Example: Polyamides are commonly formed from long chain molecules which provides them with strength. Polyesters These are formed in a reaction between dicarboxylic acids and a diol, producing an ester linkage. Example: -COO- is the ester linkage. https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc Terylene (PET) is a common polyester made from ethanediol and 1,4-benzenedicarboxylic acid. Example: Polypeptides These molecules are formed from multiple amino acids. A single monomer can produce a polymer due to the presence of both a -NH and -OH group. Example: -CONH- is the peptide linkage. https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc Hydrolysis Condensation polymers can be broken down back into the constituent molecules by the addition of H2O. This is because water is attracted to the polar regions of the polymer meaning the links can be broken down. Example: Uses of Condensation Polymers Condensation polymers contain polar bonds such as those in the ester and amide links. Hydrogen bonding and dipoles can also form between separate polymer chains, holding them together in a strong structure. Example: This makes the polymers very useful for things such as bulletproof vests and heat protective materials. https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc 3.3.12.2 - Disposal of Polymers All polymers are very useful but can be hard to get rid of as waste products. Polyalkenes (addition polymers) are very inert with non-polar bonds meaning they are not easily broken down by species in nature. They are non-biodegradable. Therefore they have to be broken down by burning which produces harmful products such as SO2 or CO, this can lead to acid rain. Polyesters and polyamides can be broken down through hydrolysis due to the polarity within the polymer molecules. Therefore they are biodegradable and can be broken down easily in nature by naturally occurring water or moisture. This means polyester and polyamides can be put into landfill and will gradually break down. Some plastics can also be recycled, saving natural resources and reducing the amount of waste that has to be put into landfill. However, it is a difficult and time consuming process as all the plastics have to be sorted and washed before they can be recycled. Example: https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc
