Nylon Kingthermal decomposition and hydrolysis reactions

WhenNylon KingThermal decomposition occurs, the molecular weight of the main chain to reduce the molecular weight of the main chain to reduce the melt viscosity is the first manifestation, causing the three-dimensional structure of the melt viscosity to rise, and become a gel, become insoluble infusible material. It is believed that the main reason is due to the nature of nylon king.

In an inert gas atmosphere, nylon king can be maintained for a period of time.300°CBut after a long time, obvious decomposition can be seen, producing ammonia and carbon dioxide. The products of decomposition are cyano and vinyl groups in the absence of oxygen.

In the presence of oxygen and water, nylon king in200C showed obvious decomposition tendency. In the presence of oxygen, heating can also cause cross-linking between molecular chains

Nylon KingIt is stable to room temperature water and boiling water, but it can be hydrolyzed in a high temperature environment, especially in a molten temperature state. In addition, the nylon king is also very stable in alkaline aqueous solution, even in10%NaOHsolution in85℃ treatment16Hours also do not see obvious changes. However, it is easy to hydrolyze in some acidic aqueous solutions.

 Nylon KingMolecular weight and molecular weight distribution

Considering the nylon kingofadaptability and processability, nylon king usually has15,000To30,000The molecular weight is adjusted, and if the molecular weight is too large, the molding processability deteriorates. Methods of measurement have been developed for a range of molecular weight polyamides, such as viscometry (solution viscosity method and melt viscosity method), then end group analysis (neutralization titration, colorimetry, potentiometric titration, conductometric titration), light scattering, osmometry, melt conductivity method, the solution viscosity method, where the conditions are more easily carried out in the laboratory.