The Analysis of Synergistic Effects of Zeolites applied in Intumescent Halogen-free Flame-retardant ABS Composites.

Ammonium polyphosphate (APP) and pentaerythritol (PER) were selected to form intumescent flame-retardant (IFR) and halogen-free flame-retardant ABS/IFR/zeolite composites were prepared by melt blending. The influences of zeolite 4A, 13X on thermal behavior of mass loss, flame-retardant performance, microstructure, mechanical properties, and processability of composites were investigated. The results showed that zeolite 4A with a lower Si/Al ratio, stronger surface polarity, and lower loading not only had a better synergistic effect with IFR, which promoted the catalytic esterification of IFR, stabilized the charred residue, and made ABS/IFR composites possess higher flame-retardant performance, but also was beneficial to improving the mechanical properties and processability of composites. When the content of zeolite 4A was 1 wt%, ABS/IFR composites had better comprehensive properties. Its limiting oxygen index (LOI) value, impact strength, tensile strength, flexural strength, modulus, and melt index were 32.6%, 3.4 KJ/m2, 39 MPa, 38.7 MPa, 1337 MPa, and 24.5 g/10 min, respectively. [ABSTRACT FROM AUTHOR]