More organic chemistry - AQACondensation polymerisation - Higher
Alkanes, alkenes, alcohols and carboxylic acids are different homologous series of organic compounds. Naturally occurring and synthetic polymers can be formed from a variety of monomers.
In addition polymerisationChemical reaction in which unsaturated monomers (small molecules) join together by addition reactions to produce a polymer (long molecule)., the monomerSmall molecule, usually containing a C=C bond, that can join end to end with other monomers to form a polymer molecule. must have a C=C double bondA covalent bond resulting from the sharing of four electrons (two pairs) between two atoms.. However, in condensation polymerisationChemical reaction in which monomers (small molecules) join together to produce a polymer and a small molecule such as water., the monomers do not need a C=C double bond but they do need two functional groups.
When two monomers react in a condensation reaction, a small molecule (usually water) is produced as a by-productSomething that is produced as a waste product..
Making polyesters
Polyesters occur naturally as biological polymers, but can also be made artificially. Man-made polymers are often used in clothing. Polyesters are an example of a condensation polymer. A simple polyester can be made from a monomer which has two hydroxyl groups (-OH) and another monomer which has two carboxylic acid groups (-COOH).
For example, ethane diol (HO-CH2-CH2-OH) can react with butanedioic acid (HOOC-CH2-CH2-COOH):
n HO-CH2-CH2-OH + n HOOC-CH2-CH2-COOH → (-CH2-CH2-OOC-CH2-CH2-COO-)n + 2n H2O
We can simplify the equation by using symbols to represent the carbon chain in the middle of each
of the two monomers.
n HO-■-OH + n HOOC-♦-COOH → (-■-OOC-♦-COO-)n + 2n H2O
