14 июля, 2015 
Malyar Buffers are often added to stabilise the pH of the reaction mass. The reasons for the need for buffers are as below:
a) some surfactants are pH sensitive with regard to micelle formation and latex stability
b) some initiators are pH sensitive
c) copolymerisation may occur better at a specific pH, e. g. acrylic acid and methacrylic acid do not form copolymers easily above pH 5.
d) some monomers may be hydrolysed at alkaline pH.
Typical buffers employed commercially are borax, sodium hydrogen phosphate and sodium bicarbonate. Most latices are used at pH greater than 7.5. Where a buffer has been employed to keep the pH acidic during polymerisation, it is often necessary to adjust the final pH upon completion of the polymerisation. Ammonia is frequently added on completion of polymerisation to ensure the final latex is alkaline, but care must be exercised in its use since destabilisation of the latex can result.
The pH stability of the latex is dependent on the chemical nature of the polymer. Persulphate initiators tend to give acidic residues and buffers are necessary to keep the pH of the system between pH 4 and pH 5. Above pH 9 amino substituted monomers tend to become colour sensitive. Where acidic monomers are present the stability is usually good at low pH values.
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