Investigation of the properties of polystyrene-based wood plastic composites: effects of the flame retardant loading and magnetic fields

Abstract

<jats:title>Abstract</jats:title> <jats:p>Polystyrene-based wood plastic composites (WPCs) containing ammonium polyphosphate (APP) and iron (Fe) powder were prepared in this work by solution blending with the aid of an alternating magnetic field. The mechanical, electrical, thermal and fire performances of the WPCs were analyzed through mechanical testing, thermogravimetry and CONE calorimeter. The addition of Fe powder decreased the tensile strength and increased the impact strength. The APP promoted the formation of sufficient char on the material’s surface and enhanced the flame retardant properties. Furthermore, an alternating magnetic field was used to align the Fe powders. After the magnetic treatment, the electrical conductivity and thermal properties were found to increase considerably compared with those without treatment. The <jats:italic>Agari</jats:italic> model presented the most reasonable prediction of thermal conductivity as a function of Fe content among three classical thermal conduction models. According to the morphological observations, the iron particles in the composites tended to rearrange along the direction of the magnetic field after treatment, resulting in the enhancement of both thermal and electrical conductivities. The prepared WPCs in this study exhibited good flame retardant properties together with the acceptable mechanical properties of the composites.</jats:p>

A Branched Polyelectrolyte Complex Enables Efficient Flame Retardant and Excellent Robustness for Wood/Polymer Composites

“…The tensile and impact strength significantly increases to 22.28 MPa and 6.77 kJ/m 2 for WPC with 15% PEC. As compared to the mechanical properties of some other flame retardant-WPC [2,[27][28][29][30][31][32][33] (Figure 7c), such as WPC with expandable graphite, APP, and synergist, even some other phosphorus nitrogen flame retardants, they generally have a lower impact (1.9~6.7 kJ/m 2 ) or tensile strength (10.4~22.1 MPa), which cannot take into account both, so the overall mechanical properties are not ideal. On the contrary, PEC obviously generates a synchronous promotion on strengthening and toughening WPC.…”

“…Hence, such "soy-bean" PEC particles are evenly distributed within composites (Figure 7(f1,f2)). During stretching, the stress transfers effectively from the HDPE matrix to wood fibers through the enhanced interface via hydrogen bonding interactions, penetration, and [2,[26][27][28][29][30][31][32]. SEM images of WPC (d 1 ,d 2 ), WPC/APP 15% (e 1 ,e 2 ), WPC/PEC 15% (f 1 ,f 2 ), and WPC/PEC 25% (g 1 ,g 2 ).…”

“… Mechanical properties and fractural morphology of WPC with APP and PEC: ( a ) Strain–stress curves, ( b ) impact strength, and ( c ) comparison with other reported flame retardants [ 2 , 26 , 27 , 28 , 29 , 30 , 31 , 32 ]. SEM images of WPC ( d 1 , d 2 ), WPC/APP 15% ( e 1 , e 2 ), WPC/PEC 15% ( f 1 , f 2 ), and WPC/PEC 25% ( g 1 , g 2 ).…”