Additive

According to the principle of chemical reactions, additive can only exert its coupling effect under hydrolysis conditions, but this does not mean that water must be added to the system. The water adsorbed and bound in the material and the water vapor in the air can usually meet the requirements for hydrolysis. Whether additive is pre hydrolyzed depends on specific conditions.

Hydrolyzed additive usually has poor stability and short shelf life, so it should be used now rather than stored for a long time. If the additive solution has obvious viscosity increase and gel like suspended precipitation, it means that most additive is invalid due to self polymerization, and this additive solution can no longer be used.

The solvent for additive is usually water, alcohol, or a mixture thereof, without deionized water, but never water containing fluoride ions.

The concentration of additive in aqueous solution should not be too high, usually below 5%, otherwise the self polymerization rate of additive hydrolysate will be significantly accelerated, which can easily cause solution stratification and affect use and storage.

Non amino additive generally needs to be hydrolyzed at pH 3-5, and weak acids such as formic acid and acetic acid are usually used to adjust the pH value. However, the hydrolysis of additive must be accompanied by sufficient stirring, which can last up to 12 hours.