Curing Agent ManufacturersExplain the curing temperature and heat resistance of curing agent
The curing temperature of all kinds of curing agents is different, and the heat resistance of curing objects is also great. Generally, a curing agent with high curing temperature can be used to obtain excellent heat-resistant curing. For added polymerization curing agents, the curing temperature and heat resistance are increased in the following order:
The heat resistance of catalytic polymerization curing agent is generally at aromatic dopamine level. The heat resistance of anionic polymerization (tert-amine and imidazole antiquities) and cationic polymerization (BF3 complexes) is basically the same, which is mainly because the initial reaction mechanism is different, but all form the mesh structure of ether bond bonding.
The curing reaction belongs to the chemical reaction, which is greatly affected by the curing temperature, the temperature is increased, the reaction speed is accelerated, the gel time is shorter, and the value of the gel time decreases with the curing temperature, which tends to decrease in a straight line. However, the curing temperature is too high, often make the curing properties decline, so there is an upper limit of the curing temperature, the curing speed and curing properties must be selected to compromise the temperature, as the appropriate curing temperature. According to the curing temperature can be divided into four types of curing agent: Low temperature curing agent curing temperature below room temperature, room temperature curing agent curing temperature of room temperature ~50℃, medium temperature curing agent for 50~100℃, high temperature curing agent curing temperature of more than 100 ℃.
There are few curing agents belonging to low temperature curing type, such as T-31 type, multi-isocyanate type, etc., and the modified amine and YH-82 modified amines developed and put into operation in China can be cured under 0 ℃. There are many kinds of room temperature curing type: aliphatic polyamine, lipid-ring polyamine, low molecular polyamide and modified aromatic amine. It belongs to the medium temperature curing type, which has some lipid ring polyamine, tert-amine, squinting and boron trifluoride complexes. Aromatic polyamine, anhydride, methyl phenolic resin, amino resin, dicyanamide and hydrazine are the most high-temperature curing agents.
For high temperature curing system, curing temperature is generally divided into two stages, in the gel before the use of low-temperature curing, in order to reach the gel state or slightly higher than the gel state after curing (post-cure), compared to the previous period curing for pre-curing (pre-cure).
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