ABS/PET/APP mixtures with different synergic agents (SA) were prepared for investigating the effect of SA (2, 2’-bis (2-oxazoline) (BOZ), thermoplastic phenolic resins (TPPF), manganese dioxide, montmorillonite (MMT), zinc borate, 4A Zeolite, zinc oxide (ZnO), and attapulgite) on the flame retardancy of mixtures, and the thermal degradation and charring of ABS/PET/APP was analyzed. It was concluded that a novel intumescent flame retardant containing APP (acid source and a blowing agent) and PET (carbon source) was obtained because APP mainly catalyzed PET to degrade into charring in ABS/PET/APP mixture on heating. The flammability of ABS/PET/APP mixtures with different SA was measured by the limited oxygen index (LOI) and UL-94 tests. Except for ABS/PET/APP/attapulgite mixture, ABS/PET/APP mixtures with other SA all passed the V-0 rating in UL-94 tests, the LOI of which was improved compare with ABS/PET/APP mixture. Thermo-oxidative degradation behaviors of mixtures were analyzed by thermal gravimetric analyzer (TGA), which showed an increasing char yield of ABS/PET/APP mixtures due to the addition of SA. And scanning electron microcopy (SEM) showed the denser carbon layer formation on the surface of ABS/PET/APP mixtures with SA (except for attapulgite) after burning.
