Recycling and treatment of waste curing agent in Jilin

The curing reaction is a chemical reaction, which is greatly affected by the curing temperature. The higher the temperature, the faster the reaction speed, and the shorter the gel time; The logarithm of gelation time decreases linearly with the increase of curing temperature. However, if the curing temperature is too high, the performance of the cured product will often decline, so there is an upper limit of the curing temperature; Select the temperature that makes a compromise between the curing speed and the properties of the cured product as the appropriate curing temperature. According to curing temperature, curing agents can be divided into four categories: low-temperature curing agents curing temperature below room temperature; The curing temperature of room temperature curing agent is between room temperature and 50 ℃; Medium temperature curing agent is 50~100 ℃; The curing temperature of high-temperature curing agent is above 100 ℃. There are few kinds of curing agents that belong to low temperature curing type, such as polyurethanes, polyisocyanates, etc; T-31 modified amine and YH-82 modified amine developed and put into production in China can be cured below 0 ℃. There are many kinds of room temperature curing type: aliphatic polyamines, alicyclic polyamines; Low molecular polyamide and modified aromatic amine, etc. A part of alicyclic polyamines, tertiary amines, midazoles and boron trifluoride complexes are of medium temperature curing type. The high-temperature curing agents include aromatic polyamines, acid anhydrides, resol resins, amino resins, dicyandiamide and hydrazide.

For the high-temperature curing system, the curing temperature is generally divided into two stages. The low-temperature curing is adopted before the gel. After the gel state or the state slightly higher than the gel state is reached, the high-temperature heating is used for post cure. Compared with the previous stage, the curing is pre cure.

In terms of hue, alicyclic group is shallow and basically transparent, while aliphatic group and aromatic group have significant coloring degree. In terms of viscosity, there are also great differences. The alicyclic group is only a fraction of Pa · s, while polyamide is very viscous, up to several Pa · s, and most aromatic amines are solid. The length of application period is exactly opposite to the curing property. The aliphatic group has high reactivity, while the alicyclic group, amide and aromatic group decrease in turn.

Different range of products have different performance; High reactivity, rapid curing at room temperature or low temperature; Relatively insensitive to humidity. It has certain color stability; Good chemical corrosion resistance, especially solvent resistance; Good high temperature performance when used for thermal curing; Good chemical resistance and good electrical and mechanical properties.