Synthesis, Characterization Of Benzoxazine Contained DOPO Based On Bisphenol A And Its Copolymerization Modification With Epoxy

1.Using appropriate materials to synthesized benzoxazine monomer. Double benzoxazine based on bisphenol A (DBOZ) was synthesized by using bisphenol A, aniline and paraformaldehyde with the mole ratio for 1:2:4. Using FT-IR,NMR,DSC and TG to characterized the chemical structure, the curing characteristics and the thermostability of DBOZ. All the results show that the resin has high heat resistance.2.From the standpoint of molecular design, we take the modification researchs of benzoxazine resin. Using materials of double benzoxazine based on bisphenol A and DOPO, THF as solvent was synthesized the single benzoxazine contained DOPO based on bisphenol A (DBDO). Using FT-IR, NMR to characterized the chemical structure of DBDO.Results show that the synthetic compounds is the target product. In N2 atmosphere, the initial decomposition temperature of DBDO is 353℃. In the temperature of 443℃, the fastest speed of decomposition was achieved, in the temperature of 800℃, the carbon residue rate was 39.60%.3. Using the method of molecular design, The reaction intermediate bisphenol A contained double DOPO(2DO) was synthesized by using double benzoxazine based on bisphenol A(DBOZ) and DOPO with THF as solvent。And the double benzoxazine contained double DOPO based on bisphenol A(2DD) was synthesized by using 2DO, aniline and paraformaldehyde. Using FT-IR, NMR to characterized the chemical structure of 2DO and 2DD. The curing characteristics was studied by DSC and the thermostability was studied by TG. Compared with double benzoxazine based on bisphenol A, the initial decomposition temperature increased near 41℃, the fastest speed of decomposition improved near 70℃ and the carbon residue rate increased near 3.21%.4. From the perspective of molecular design and blending modification, we take the modification researchs of benzoxazine resin. Single benzoxazine contained bis DOPO based on bisphenol A(1DD) was synthesized by using 2DO, aniline and paraformaldehyde. Using FTIR, NMR to characterized the chemical structure of 1DD. The curing characteristics was studied by DSC and the thermostability was studied by TG. Then the product was blended with epoxy resin of the mass ratio 0.5/1, according to certain procedures for heat curing, and last got the copolymer P1DD-ER. The flame retardant properties of copolymer was investigated by the UL-94 vertical burning test and limit oxygen index (LOI).Results show that the preparation of benzoxazine can be used as the curing agent of epoxy resin. And the copolymer has good flame retardant performance. The LOI can reach 37. The grade of UL94 is V-0.