In fact, the curing temperature of different types of curing agents is different, and the heat resistance of the cured products will also be different. How much do you know about this? Do you know the curing temperature of different types of Shandong epoxy resin curing agents? Is it unclear? Next, Kangyu New Materials, an epoxy resin manufacturer, will be introduced to you below, hoping to help everyone.
Generally speaking, using a curing agent with a high curing temperature can obtain a cured product excellent in heat resistance. For the addition polymerization type curing agent, the curing temperature and heat resistance increase in the following order: aliphatic polyamine<alicyclic polyamine<aromatic polyamine≈phenolic formaldehyde<anhydride.
According to the curing temperature, the curing agent can be divided into four categories: the curing temperature of the low-temperature curing agent is below room temperature; the curing temperature of the room temperature curing agent is room temperature ~ 50 ℃; the curing temperature of the intermediate temperature curing agent is 50 ~ 100 ℃; the curing temperature of the high temperature curing agent is above 100 ℃ .
Epoxy resin curing agent
There are few types of curing agents belonging to low-temperature curing types, such as poly-alcohol type and polyisocyanate type. T-31 modified amine and YH-82 modified amine developed and put into production in China can be cured below 0℃.
The reaction is a chemical reaction, which is greatly affected by the curing temperature. The temperature increases, the reaction speed is accelerated, and the gel time becomes shorter; the logarithm of the gel time generally decreases linearly with the increase of the curing temperature, but the curing temperature is too high, which often causes curing The physical properties are reduced, so there is an upper limit of the curing temperature; it is necessary to select a temperature that compromises the curing speed and the cured product performance as the appropriate curing temperature.
There are many types of room temperature curing types: aliphatic polyamines, alicyclic polyamines; low molecular polyamides and modified aromatic amines. Some of the middle-temperature curing types include cycloaliphatic polyamines, tertiary amines, azoles, and boron trifluoride complexes. According to epoxy resin manufacturers, aromatic polyamines, acid anhydrides, resole phenolic resins, amino resins, dicyandiamide, and hydrazides are among the high-temperature epoxy resin curing agents.
The heat resistance of the catalytic addition polymerization type curing agent is generally at the level of aromatic polyamines. The heat resistance of anionic polymerized (tertiary amine and imidazole compounds) and cationic polymerized (BF3 complex) is basically the same. This is mainly because although the initial reaction mechanism is different, they eventually form a network structure of ether bonds. .
Epoxy resin curing agent
For high-temperature curing systems, the curing temperature is generally divided into two stages. Low-temperature curing is used before the gel. After reaching the gel state or a state slightly higher than the gel state, the post-cure is heated and heated at a high temperature. The previous stage curing is pre-cure.
The epoxy resin needs to react with the curing agent to generate a three-dimensional three-dimensional structure to have practical value. Therefore, the structure and quality of the curing agent will directly affect the application effect of epoxy resin. The research and development of curing agents abroad are far more active than epoxy resins. Compared with the varieties of epoxy resins, there are more varieties of curing agents, and the confidentiality is very strong.
Each development of a new curing agent can solve one problem, which is equivalent to developing a new epoxy resin or opening up a new use of epoxy resin. It can be seen that the development of new curing agents is far more important than the development of new epoxy resins.