The Effect of Fire Retardants on the Flammability, Mechanical Properties, and Wettability of Co-Extruded PP-Based Wood-Plastic Composites

Abstract

In this work, fire retardants (FRs) such as aluminum trihydroxide (ATH), zinc borate (ZB), melamine, graphite, and titanium oxide (TiO 2 ) were loaded into the shell layer of a co-extruded polypropylene (PP)-based wood-plastic composite (WPC). The incorporated retardants reduced the peak of the heat release rate by 8 to 22%, depending on the type of FR. Other studied parameters, such as ignition time and mass loss rate, were improved after the FR loading. The total heat release decreased slightly (except for the graphite-WPC). The effective heat of combustion was independent of the presence of the FR or, in the case of graphite, slightly increased. Carbon monoxide production increased (ZB, graphite) or was not changed significantly (ATH, melamine, and TiO 2 ). It was also observed that the tensile strength improved after the FR loading; however, the tensile modulus decreased, except for the graphite-WPC. The impact strength improved or was independent of the FR loading, as in the case of the sample with ATH. The wettability of the composites decreased with filler loading, except for ZB, which showed the highest water absorption value among the studied composites.

Effect of expandable graphite on thermal and flammability properties of poly(lactic acid)‐starch/poly(ɛ‐caprolactone) blend systems

“…The EHC for the composites was higher than that for the blend, but decreased with increase in EG content. Turku et al and Wei et al reported similar findings. Blending PLA‐starch with PCL led to a 40% increase in av‐MLR compared to PLA‐starch alone, and this is attributed to PCL with a high av‐MLR.…”

Effect of Pentaerythritol on the Properties of Wood-Flour/Polypropylene/Ammonium Polyphosphate Composite System

“…Because of their excellent performance, low cost, high dimensional stability throughout their lifetime, and high relative strength and stiffness (Stark et al 2010;, WPCs have been widely used in decking products, automotive parts, and construction products (Ashori 2008;Ndiaye et al 2008;Leu et al 2012;Arao et al 2014;Turke et al 2014;Wu et al 2014). However, the main drawback limiting wider application of WPCs is their high flammability, which is because the two main components (woodflour or fiber and plastic) are themselves flammable (Li et al 2010;Arao et al 2014;Pan et al 2014).…”

The influence of carbon‐based fillers on the flammability of polypropylene‐based co‐extruded wood‐plastic composite

“…Another reason for this was the too small loading amount of EG. According to the results of our previous research, the incorporation of 10 wt% of graphite reduced the pHRR by 13%; also, the ignition time was significantly delayed [23]. Naumann et al report that the pHRR was reduced by 55% after 15% of EG loading, and the THR was significantly reduced as well [5].…”

“…The composites with the modified outer layer produced by recently invented co-extrusion techniques can improve the mechanical and physical properties [21][22][23] as well as durability [24,25]. It was also shown that the presence of FRs in the shell layer reduced flammability [23]. This result was comparable with the FRs action in the traditional WPC [26].…”

“…Taken into account that the most destructive processes in composites are surface‐controlled processes, the modification of the material surface could improve composite performance as well as save the cost of the final product. The composites with the modified outer layer produced by recently invented co‐extrusion techniques can improve the mechanical and physical properties as well as durability . It was also shown that the presence of FRs in the shell layer reduced flammability .…”