What is the relationship between the ammonia value of amino silicone oil and yellowing?

The various properties that amino silicone oil imparts to fabrics, such as softness, smoothness, and fullness, are mostly caused by the amino groups in the polymer. The amino content can be expressed by the ammonia value, which refers to the number of milliliters of hydrochloric acid of 1 equivalent concentration required to neutralize 1 g of amino silicone oil. Therefore, the ammonia value is directly proportional to the mole percentage of the amino content in the silicone oil. The higher the amino content, the higher the ammonia value, and the softer and smoother the finished fabric will feel. This is because the increase in amino functional groups greatly increases its affinity for the fabric and forms a more regular molecular arrangement, thus giving the fabric a soft and smooth feel. .

However, the active hydrogen in the amino group is easy to oxidize to form a chromophore, causing the fabric to become yellowish or slightly yellowish. In the case of the same amino group, obviously as the amino group content (or ammonia value) increases, the probability of oxidation increases, and the yellowing becomes serious.

As the ammonia value increases, the polarity of amino silicone oil molecules increases, which provides a favorable prerequisite for the emulsification of amino silicone oil, which can be made into microemulsions, and the selection of emulsifiers and the size and distribution of the particle size in the emulsion are also related to The ammonia value is related.