Polymers flame retardant can be divided into halogen and halogen-free two categories. The serious disadvantages of halogen flame retardant is that it reduces UV stability of flame retardant polymer substrate. It burns to produce more smoke, toxic gases, corrosive gases, and halogen flame retardants generally use with antimony trioxide together, therefore, smoke and toxic gases generate more.
In the research and application of fire retardant materials, people have gradually realized that smoke suppression and flame retardancy of equal importance. But for some materials, smoke suppression even more important than flame retardant, such as widely used materials PVC.
There are variety of halogen-free flame retardant. According to the types of flame retardant elements, they are often divided into magnesium-aluminum, phosphorus, nitrogen, phosphorus-nitrogen, Silicon, antimony, boron, molybdenum and graphite etc. Currently, consumption of halogen-free flame retardant in industry mainly are phosphorus (phosphonic) acid (includes halogen-containing derivative), zinc Borate, hydroxide, magnesium hydroxide, red phosphorus and antimony trioxide. Flame retardants are one of the most important polymer processing additives.
DOPO derivatives of its phenolic hydroxy or amino derivatives can be used as curing agent for polymers. They cured epoxy resin are very different from brominated epoxy resins, especially in flame retardant, thermal stability. Today's research and development of organic phosphorus compounds have a rapid development from chain-like structure to the ring. Such as phosphine phenanthrene compounds - DOPO and its derivatives has been paid attention due to its unique molecular structure (benzene and phenanthrene ring structure) and and have shown a great deal of excellent performance. So flame retardant DOPO derivative applications are great. Due to DOPO derivatives Ⅲ has two phenolic hydroxyl group, it can also be used as a curing agent for epoxy resin. Compared with TBBA for traditional curing epoxy, epoxy resin cured by it, Tg in General 40 ℃ higher, Td and charring rate is also higher. No trickle down and produce black smoke during combustion phenomenon, so it is very suitable as a circuit board substrates. If you have interest, please follow us at OKCHEM Linkedin Page or visit www.okchem.com, thanks!