Organophosphorus halogen-free flame retardants can be classified according to the differences in compound structures, mainly including the following categories:
Phosphate esters: Phosphate esters are thermally stable, high-boiling-point substances and also have a certain plasticizing effect. It decomposes into phosphoric acid or polyphosphoric acid through combustion and then reacts with polymers to exert flame-retardant effects. For example, tri (β -chloroethyl) phosphate, tributyl phosphate (TBP), triphenyl phosphate (TPP), etc. Some phosphate ester flame retardants have both flame-retardant and plasticizing functions. For instance, bisphenol A bis (diphenyl phosphate) (BDP) has a very high flame-retardant efficiency for oxygen-containing polymers.
Phosphonate esters: Like phosphate esters, they belong to an important category of organophosphorus halogen-free flame retardants, but specific product and application details are not explicitly mentioned in the reference information.
Phosphine oxides: For instance, trihydroxymethyl phosphine oxide (THPO) is a reactive organophosphorus flame retardant. Its molecular structure contains an active hydroxymethyl group, which can replace glycerol as a starting agent to participate in the polyether synthesis reaction. It is connected by P-C bonds and has excellent hydrolysis resistance.
Phosphorus heterocyclic compounds: such as DOPO and its derivatives, these flame retardants have high thermal stability and flame retardant efficiency, and are often used for flame retardant modification of polymer materials.
Phosphate ester polymers: such as polyphosphate ester flame retardants with hyperbranched structures (HPPEA), these flame retardants, through special molecular structure design, enhance flame retardant performance and compatibility with the substrate.
Organic phosphate type: This type of flame retardant usually contains phosphorus and organic groups. Through the flame-retardant effect of phosphorus and the plasticizing and compatibilizing effects of organic groups, the flame retardant performance of materials is jointly improved.
