Synergistic Effect Of Nano-REO And CNT On The Flame Retardant Properties Of A Novel PP/IFR System

In the system of polypropylene(PP),ammoniumpolyphosphate(APP),dipentaerythritol(DPER),added carbon nanotubes(CNT) and rare earth oxides(REO) as a flame retardant synergist and prepared by melt blending PP composites.And selected three typical outer electron structure:Lanthanum oxide(La2O3),Cerium oxide(CeO2),Neodymium oxide(Nd2O3)Then studied the synergist effectt on composites flame retardancy and thermal stability properties.The research results were summarized as follows:(1) The system consisting of flame retardants IFR(APP:DPER =3:1) and synergists could effectively improve the retardancy of PP. When the addition of REO and CNT was1%wt,PP could achieve UL94 V-0 level and its LOI value increased from 22.1% to 32.1%.At this time, flame retardant PP system also performed well in the effectivity(EFF) and synergistic effectivity(SE).(2) Synergistic effect of REO with different catalytic activity in PP was investigated systemically. REO increased the thermal stability in high temperature range and final char yield and decreased the Tonset of IFR and PP slightly.(3) Cone also showed REO and CNT had excellent synergistic flame retardant effect.The flame retardant systems could restrain combustion heat release of PP, and significantly reduce the peak of heat release rate PHRR.(4) The image of char showed that a small amount of REO and CNT could catalyze the esterification crosslinking reaction, promote the formation of dense carbon layer and had good antioxidant capacity to improve the resistance of condensed phase flammable.(5) For instance,Nd2O3?The system could make carbon residue of PP on burning increased, and regularity and dense carbon layers formed could effectively insulate thermal and oxygen in surroundings so as to enhance flame retardancy. In the system, Nd2O3 and CNT palyed the role that promoted to form char and stabilized the residual carbon.