Comparative study of thermal degradation and flame retardancy between straw flour and wood flour on wood–polypropylene composites

Abstract

The main aim of this study was to evaluate the thermal degradation and flame retardancy of straw flour (SF)-polypropylene (PP) composites and wood flour (WF)-PP composites. Biomass silica exists in SF, despite only 18 wt% loading of ammonium polyphosphate (APP); the APP in combination with biomass silica can effectively improve the flame retardancy on total heat release, heat release rate (HRR), mass loss rate, time to ignition (TTI), and limited oxygen index; it can obtain UL-94 V-0 rating, reduce the average and peak HRR by 44% and 41%, respectively, and increase the TTI by 8%. It attributes to the interaction effect between biomass silica in SF and APP, which more effectively enhances the thermal stability of the SF/PP/APP composites at high temperature and increases the char residue. The silica could form an intercalated network in char structure and then boost the physical integrity. The enhanced physical integrity and thermal stability lead to an effectively synergetic effect on flame retardancy of SF/PP/APP composites.

Fabrication of flame‐retardant wood plastic composites based on wasted bean dregs with recycled PE via mechanochemical crosslinking

“…19 Using Phosphorus-based halogenfree flame retardant combined with synergist also is a common and popular route to enable WPC to meet the demanding fire-safety requirements in industries, but they are still roughly 25 wt% needed within WPC composites. 20 Thus, there is a great deal of work to be further optimized to achieve highly effective fire retardancy, due to the wide variety of phosphorus-based flame retardant and complex interface compatibility. 21 As far as we know, the dispersion and compatibility of fillers within polymer matrix can be greatly improved by insitu polymerization, 22 obtaining a satisfactory composite with evolutionary properties.…”

“…is considered as an economical and environmentally friendly approach to enhance fire‐safety of WPC, whereas it has less benefit for limiting oxygen index (LOI) of materials and deteriorates their mechanical properties 19 . Using Phosphorus‐based halogen‐free flame retardant combined with synergist also is a common and popular route to enable WPC to meet the demanding fire‐safety requirements in industries, but they are still roughly 25 wt% needed within WPC composites 20 . Thus, there is a great deal of work to be further optimized to achieve highly effective fire retardancy, due to the wide variety of phosphorus‐based flame retardant and complex interface compatibility 21 …”