Elaborate on the application characteristics of crosslinking agents in the textile industry

Elaborate on the application characteristics of crosslinking agents in the textile industry:

Crosslinking agent, also known as curing agent, curing agent or hardening agent, is mainly used in polymer materials, such as various rubbers or resins, to improve the strength, heat resistance, wear resistance and other properties of rubber. Crosslinking agents can maintain their stable performance at normal temperatures, so they can be stored at room temperature for a long time.

In order to improve durability, textiles need to be chemically treated with crosslinking agents during post-processing. Crosslinking agents act as bridging agents between linear molecules, allowing multiple linear molecules to bond and crosslink into a network or bulk structure. Crosslinking agents used in textiles are a type of compound that can form covalent bonds between fiber macromolecules and adhesive molecules, as well as between fiber macromolecules and auxiliary molecules, thereby improving their morphological stability, elasticity, and other physical and chemical properties.

Another common crosslinking agent in solvent based coatings is isocyanate crosslinking agent, which is currently not widely used in water-based textile coatings. Isocyanate R-N=C=O has two impurity accumulated double bonds, which are very active and easily react with other compounds containing active hydrogen. Therefore, this type of crosslinking agent generally exists in the form of trimer with better stability.

The main reactive group in isocyanate crosslinking agents is NCO, which reacts with hydroxyl, carbonyl, and amide groups to form multiple urethane bonds. This reaction can be carried out during high-temperature drying and can also be cured at low temperatures. It requires low construction conditions and is particularly suitable for the field of water-based textile coatings on high-speed assembly lines. Due to the long chain segments of the formed urethane bonds, it also has better flexibility than melamine crosslinking agents.