The enhancement of the flame retardance of bamboo fibre/HDPE composites: Cerium doped H2Ti2O5·H2O nanotubes effects

Abstract

In this study, H2Ti2O5·H2O nanotubes (TNTs) and Ce-doped titanate nanotubes (Ce-TNTs) were synthesised via hydro-thermal synthesis and incorporated into bamboo fibre/high-density polyethylene (HDPE) (BH) composites to enhance the flame retardance of these composites. Transmission electron microscopy (TEM), X-Ray Diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) analyses showed that Ce ions were well doped into the crystal lattice of TNTs, but these ions slightly affected the sizes of TNTs. Both 6 wt% TNTs and 6 wt% Ce-TNTs were well distributed in the bamboo fibre/HDPE matrix, and promoted the formation of a network structure in the BH composites. Cone calorimetry test and limiting oxygen index test indicated that TNTs enhanced the flame retardance of the BH composites. Compared to those of BH0, the time to ignition (TTI) of bamboo fibre/HDPE composites incorporating TNTs (BHT) was delayed from 29 s to 36 s, and peak heat release rate (pHRR), average heat release rate (av-HRR) and total heat release (THR) of BHT decreased from 658.6, 222.7 and 55.8 kW/m2 to 503.0, 158.0 and 39.6 kW/m2, respectively. The improvement mainly attributed to adsorption effect of TNTs. When Ce-TNTs were used as a substitute for TNTs, the TTI of bamboo fibre/HDPE composites incorporating Ce-TNTs (BHC) composites were further delayed to 41 s, and pHRR, av-HRR and THR decreased to 399.1, 138.0 and 34.5 kW/m2, respectively.