Influence of halloysite nanotubes coated with zinc hydroxystannate on the flammability of PVC/ABS blends

Halloysite nanotubes (HNTs) coated with zinc hydroxystannate (ZnSn(OH)6) (C-HNTs) was synthesized by homogeneous precipitation technique. The results of transmission electron microscopy (TEM) and X-ray diffraction (XRD) analysis show that HNTs can be uniformly coated with ZnSn(OH)6 when m(ZnSn(OH)6):m(HNTs)=1:10. The effects of C-HNTs on the flame retardant properties and thermal stability of PVC/ABS blends were investigated by the oxygen index testing, cone calorimeter instrument(CONE)and thermogravimetric analysis (TGA). The results indicate that the flame retardance and smoke suppression properties of PVC/ABS blends filled with C-HNTs are improved. Limited oxygen index (LOI) is increased to 36% and smoke production rate is decreased by 51%. By adding 4 phr C-HNTs, the charring residue at 850℃ for PVC/ABS blends is increased by 14.06%. It is also found that with the content of C-HNTs increasing, the tensile strength of the PVC/ABS blends decreases, while its elongation at break and impact strength increase first, and then decrease. ©, 2015, Chengdu University of Science and Technology. All right reserved.