Synthesis Of Phosphonates Reactive Flame Retard Ant And Their Application In Polyurethane

Rigid plyurethane foam (RPUF) products are widely applied in particular, the global RPUF products accounted for about 1/2 of consumption, with good thermal insulation effect. But this material has a fatal drawback is flammable, limiting its application. In this paper, using catechol and o-phenylphenol as raw materials to synthesis which contains P-H bond phosphonate ester intermediates BDPO and DOPO reaction with the C=O bond and the C=N bond containing compounds based on the reactivity of addition reaction. Further seven kinds of organic phosphorus, nitrogen flame retardants were designed and synthesized, and the application in RPUF material was studied. All test results show that the flame retardant has a positive effect on the modification of the RPUF. The main contents as follows:1、In the synthesis of flame retardant section, the paper discusses respectively the synthesis process of two kinds of flame retardants. The first category is the organic phosphorus flame retardant, phosphonates intermediates BDPO were synthesized as raw material and using catechol, phosphorus trichloride and anhydrous formic acid, then react with acetone and benzene formaldehyde to produce two kinds of hydroxyl-containing organophosphorus flame retardants BDOP and BDBM. Second types of organic phosphorus nitrogen flame retardant, another phosphonate intermediate DOPO was synthesized from o-phenylphenol, phosphorus trichloride as the main raw materials, DOPO and BDPO react with three kinds of containing C=N bond (Schiff base) to generate organic phosphorus nitrogen flame retardant compound BDMD、PBMD、PBMO、PDOP and PDOM. Seven kinds of flame retardant was synthesized, the yield was more than 60%. And with 1H NMR、31P NMR、IR and elemental analysis characterization of all compounds structure, with TGA analysis the thermal properties of flame retardant.2、In contrast, different proportions of BDOP, BDMD, PBMD and PDOP were used for the flame retardant modification of RPUF, respectively. And with LOI, UL-94, CONE and TGA on the flame retardant RPUF combustion properties and thermal performance test. All flame retardant RPUF samples in the UL-94 test at grade V-2 or above, TGA results showed that the flame retardant RPUF compared with the neat RPUF show good thermal stability, the residual carbon layer structure after combustion of SEM characterization results show that organic phosphorus flame retardant have dense carbon layer structure, organic phosphorus nitrogen flame retardant have intumescent characteristics. When the flame retardant PBMD adding amount was 10%, the limiting oxygen index is increased from 21.0 to 28.2, the parameters of CONE indicate the flame retardant PDOP has good flame retardant property of RPUF, the bending and compressive properties tests showed that flame retardant PDOP on the flame retardant modification of RPUF did not have effect the mechanical properties.