Polyurea(PUA)is widely valued in protective coatings and structural reinforcement because of its impressive mechanical strength and resistance to corrosion.Its high flammability,together with the poor dispersion that ...Polyurea(PUA)is widely valued in protective coatings and structural reinforcement because of its impressive mechanical strength and resistance to corrosion.Its high flammability,together with the poor dispersion that often comes with simply blending in flame retardants,continues to limit its use in demanding environments.To overcome these issues,this study introduces a different approach.We grafted 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide(DOPO)onto the surface of a metal-organic framework(MOF)and then partially amino-functionalized the DOPO layer,ultimately creating an amino-modified DOPO-MOF hybrid.The introduced amino groups can directly react with the isocyanate(-NCO)groups in the PUA matrix,allowing the flame-retardant component to be integrated via reactive integration rather than physical blending.This approach helps avoid the interfacial defects and the mechanical weakening typically observed in conventional blending.With 5 wt% ZIF-67@DOPO-NH2 added to the PUA system,the composite successfully reached a UL-94 V-0 classification and showed a notable increase in limiting oxygen index(LOI),from19.2% to 23.8%.The peak heat release rate and total heat release dropped by 36.3% and 38.7%,respectively.Meanwhile,the tensile strength decreased from 25.74 to 22.52 MPa,while the elongation at break remained above 300%,indicating that the material maintained excellent toughness.展开更多
We aimed to enhance the flame retardancy of epoxy resin(EP)by synthesizing a novel,halogen-free flame retardant through a one-pot method.The synthesis utilized 9,10-dihydro-9-oxa-10-phospha-phenanthrene-10-oxide(DOPO)...We aimed to enhance the flame retardancy of epoxy resin(EP)by synthesizing a novel,halogen-free flame retardant through a one-pot method.The synthesis utilized 9,10-dihydro-9-oxa-10-phospha-phenanthrene-10-oxide(DOPO),furfurylamine(FA),and benzene propionaldehyde(BPA)as raw materials.We conducted differential scanning calorimetry(DSC)analysis to investigate the effects of FPD on the curing process and thermal properties of EP.Our findings reveal that incorporating FPD into EP can facilitate a faster curing process and increase the carbon residue post-combustion.Specifically,the FPD/EP-7 composite demonstrates a limiting oxygen index(LOI)of 34.9%and achieves a UL-94V-0 rating with a phosphorus content of 0.91wt%.These results indicate that FPD significantly enhances the thermal stability and charring rate of EP,thereby improving its flame retardancy.Although the addition of FPD slightly reduces the mechanical properties of EP,the composite material maintains excellent performance.展开更多
基金financially supported by Natural Science Foundation of Shandong Province(Grant No.ZR2021ME019).
摘要Polyurea(PUA)is widely valued in protective coatings and structural reinforcement because of its impressive mechanical strength and resistance to corrosion.Its high flammability,together with the poor dispersion that often comes with simply blending in flame retardants,continues to limit its use in demanding environments.To overcome these issues,this study introduces a different approach.We grafted 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide(DOPO)onto the surface of a metal-organic framework(MOF)and then partially amino-functionalized the DOPO layer,ultimately creating an amino-modified DOPO-MOF hybrid.The introduced amino groups can directly react with the isocyanate(-NCO)groups in the PUA matrix,allowing the flame-retardant component to be integrated via reactive integration rather than physical blending.This approach helps avoid the interfacial defects and the mechanical weakening typically observed in conventional blending.With 5 wt% ZIF-67@DOPO-NH2 added to the PUA system,the composite successfully reached a UL-94 V-0 classification and showed a notable increase in limiting oxygen index(LOI),from19.2% to 23.8%.The peak heat release rate and total heat release dropped by 36.3% and 38.7%,respectively.Meanwhile,the tensile strength decreased from 25.74 to 22.52 MPa,while the elongation at break remained above 300%,indicating that the material maintained excellent toughness.
基金Funded by the Fundamental Research Funds for the Central Universities(WUT:2023III012JL)。
摘要We aimed to enhance the flame retardancy of epoxy resin(EP)by synthesizing a novel,halogen-free flame retardant through a one-pot method.The synthesis utilized 9,10-dihydro-9-oxa-10-phospha-phenanthrene-10-oxide(DOPO),furfurylamine(FA),and benzene propionaldehyde(BPA)as raw materials.We conducted differential scanning calorimetry(DSC)analysis to investigate the effects of FPD on the curing process and thermal properties of EP.Our findings reveal that incorporating FPD into EP can facilitate a faster curing process and increase the carbon residue post-combustion.Specifically,the FPD/EP-7 composite demonstrates a limiting oxygen index(LOI)of 34.9%and achieves a UL-94V-0 rating with a phosphorus content of 0.91wt%.These results indicate that FPD significantly enhances the thermal stability and charring rate of EP,thereby improving its flame retardancy.Although the addition of FPD slightly reduces the mechanical properties of EP,the composite material maintains excellent performance.