| A series of novel phenolic hydroxyl-containing reactive-type orgnophosphorus flame retardants used in epoxy resins and alkene-containing reactive-type orgnophosphorus flame retardants used in polystyrene were synthesized. The flame retardances were tested and evaluated.By-products in the bottom products during the production of DOPO-HQ were analyzed, the structures of the two main by-products were identified as two isomers of o-2DOPO-HQ (2,5-bis(6-oxido-6H-dibenz[c,e][1,2]oxaphosphorin-6-yl)benzene-1,4-diol); causes and mechanism for the production of o-2DOPO-HQ were found during the synthesis of DOPO-HQ through experiments, and the conditions on production of DOPO-HQ were optimized. Since two active hydroxyl groups were present in the molecule of o-2DOPO-HQ with higher phosphorus content than DOPO-HQ, o-2DOPO-HQ should be good reactive-type flame retardant for epoxy resins. Therefore, o-2DOPO-HQ was synthesized starting from DOPO-HQ through successive oxidation and addition reactions; o-2DOPO-HQ exhibited excellent flame retardance according to flammability testing results.The cross-coupling reaction of DOPO with halogenated phenols were achieved for the first time, novel phenolic hydroxyl-containing reactive-type DOPO-based flame retardants used in epoxy resins were synthesized; the cross-coupling reactions of 2'-hydroxybiphenyl-2-ylphosphinic acid (HPPA) or diphenyl phosphine oxide (DPO) with halogenated phenols were studied according to the above result, new reactive-type flame retardants used in epoxy resins were synthesized.An approach for the synthesis of 2-methylene-3-phosphorylalkanoates (MPA) via S_N2-S_N2' reactions of Baylis-Hillman bromides (BHB) with R"R'P(O)H was put forward for the first time. Methyl 2-((diphenyl-phosphoryl)(phenyl)methyl)acrylate(MPA-1)was incorporated into polystyrene as reactive-type orgnophosphorus flame retardant monomer via radical polymerization, flammability testing results shown that MPA-1 greatly improved flammability of polystyrene.
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