In this paper,hexagonal boron nitride(h-BN)and ionic liquid(IL)were used as raw materials to synthesize IL functionalized boron nitride nanosheets(BNNS@IL)by in-situ exfoliation functionalization technolo-gy.BNNS has a lamellar structure with a thickness of 5～10 nm.The initial decomposition temperature of the BNNS@IL is 340 ℃,and it has good thermal stability.The flame retardant performance test showed that the limit-ing oxygen index(LOI)of BNNS@IL-PET reached 27％when the BNNS@IL addition was 2 wt％.Compared with pure PET samples,the peak heat release rate(pHRR),total heat release(THR)and total smoke release(TSP)of BNNS@IL-PET were reduced by 17.25％and 37.90％,respectively.25.90％.On this basis,the LOI value of 1 wt％ammonium polyphosphate(APP)was compounded to 30％,reaching the UL-94 V-l rating.Compared with pure PET,pHRR and THR were reduced by 44.26％and 50.14％,respectively,achieving better heat reduction and flame retardancy.SEM and Raman spectroscopy showed that BNNS@IL had both the physical barrier of BNNS and the catalytic char-forming effect of IL,and the addition of APP further promoted the dehydra-tion and carbonization of PET to produce a continuous dense expanded carbon layer and NH3 at the same time,real-izing the synergistic flame retardant effect of gas phase and condensed phase.
维普
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