The Hydrolysis Of Asa Is An Autocatalytic Reaction--a Brief Discussion On The Preservation Of Asa Raw Materials

Based on the different long carbon-hydrogen chains that make up the ASA molecule, the ASA raw materials currently used in papermaking can be divided into the following categories:

1. 16 carbons, linear, containing isomers;

2. A mixture of 16 carbons and 18 carbons, containing isomers and some branched products;

3. 18 carbons, containing isomers;

4. More than 20 carbons, linear, containing isomers

One of the advantages of using ASA is that the concentration of active ingredients in the raw materials is almost 100%, so the factory can save transportation and storage costs. Most of the ASA currently supplied on the market contains a small amount of surfactant (the purpose is to make ASA easier to emulsify), but this content is very small and can be ignored.

Before being emulsified, the ASA raw materials should be protected at all times to avoid damage by moisture. The hydrolysis reaction of ASA (see the figure below) is obviously an autocatalytic reaction. Once the hydrolysis is triggered, all the ASA raw materials in the storage tank will be consumed quickly. Generally, ASA storage tanks are filled with dry air or nitrogen to avoid the intrusion of moisture.

If there is an ASA sizing problem, it is necessary for the plant to check the quality of the ASA immediately. Hydrolyzed ASA can dissolve in the original ASA material, so it is difficult to distinguish. However, hydrolyzed ASA is more viscous and tends to separate to the bottom of the tank under the action of gravity. Therefore, when testing, samples can be taken from the bottom of the container and compared with the samples from the top. The amount of hydrolyzed ASA can be measured using infrared spectroscopy.