This work focused on the study of physical, mechanical and flame-retardant properties of polypropylene (PP)/pecan nutshell (PNS) and ammonium polyphosphate (APP) biocomposites. The effect of PNS particle size and APP content on the final properties of the biocomposites was studied. Cone calorimetry showed that the addition of 30% (by weight) of PNS to PP reduces the pHRR (peak of the heat release rate) to 41% and improves the flame retardancy of PP. PNS with APP acts synergistically and further reduces the pHRR to 69%, due to the formation of a char layer during the combustion of materials. TGA showed that PNS particle size affects the thermal stability of the compounds, and all biocomposites have two stages of decomposition and formation of a carbonaceous residue. Further, DSC showed that PNS works as a nucleating agent, reduces Δ, Hc and increases Tc of biocomposites, and this effect is more pronounced with 325 mesh particle size. UL 94 tests showed that PNS particle size affects the burning rate of the compounds and PP/PNS/APP reaches V2 rating. Finally, the addition of PNS in combination with APP produced an increase in the stiffness of the compounds, although the addition of maleic anhydride-grafted PP (PP-g-MA) provided elastic properties to PP/PNS/APP biocomposites.

This is an attempt to develop thermally stable shellac–, epoxy coating blends with flame-retardant properties. The monophosphazene and silicon precursors were synthesized with PCl5 and dichlorodimethylsilane (DCMS) as phosphorus and silicon sources, respectively. The synthesized phosphazene and silicon precursor moieties were then reacted with shellac in various concentrations to prepare the modified shellac. The shellac/modified shellac and epoxy coatings were then mixed to form the blend formulations and coated onto the mild steel panels. The structure confirmation of both the precursors was achieved using physicochemical analysis, FTIR and NMR, while the modified shellac was characterized using FTIR. Furthermore, the thermal, mechanical and flame-retardant properties of the coating blends were analyzed. The Tg values and the degradation curves showed that the coating blends with Si and P modification were more thermally stable than the unmodified shellac blends. The maximum LOI obtained was 27 for the highest concentrations of P and Si in the coating, similarly, the calculations based on the char yields of LOI also showed the similar trend of increasing values although the values were lower than the practical LOI values. The barrier properties were predicted depending on the results of water absorption and gel content values which showed that the crosslinking density was increasedwith increasing concentrations of shellac in the coating.

Despite the extensive use of polyolefins, especially in the form of lithium-ion battery (LIB) separators, their flammability limits their large-scale battery applications. Therefore, the fabrication of flame-retardant LIB separators has attracted much attention in recent years. In this work, composite separators were fabricated by applying a ceramic-based composite coating composed of a metal hydroxide as a filler and flame-retardant agent (Aluminium hydroxide, Al(OH)3) and a binder (Poly(vinylidene Fluoride-co-hexafluoropropylene), P(VDF-HFP)) to the polypropylene (PP) commercial separator. Thermal shrinkage, thickness, air permeability, porosity, wettability, ionic conductivity, flame retardancy, and electrochemical performance of the fabricated ceramic-coated composite separator were investigated. The results showed that the addition of Al(OH)3 particles improved thermal shrinkage (~8 %) and flame retardancy of the commercial separator, which can prevent dimensional changes at high temperatures and significantly increase LIBs safety. Applied 11 μ m ceramic-based coating layer on PP commercial separator had 76 % porosity that increased the value of air permeability from 278. 15 (s/100 cc air) to 312. 8 (s/100 cc air), causing much facile air permeation through the pores of commercial separator than the composite one. Furthermore, suitable electrolyte uptake and the contact angle of ceramic coated separator (135 % and 91. 19° , respectively) facilitated ion transport through the pores, which effectively improved the ionic conductivity of Al(OH)3-coated PP separator (about 1. 4 times higher than bare separator). Moreover, the cell comprising Al(OH)3-coated PP separator had better cyclic performance than that of bare PP separator. All these characteristics make the fabricated flame-retardant Al(OH)3 composite separator an appropriate candidate to ensure the safety of the large-scale LIB.

Present work reports the synthesis of phosphorus-containing imine derivative of vanillin for application in the flame-retardant (FR) polyurethane (PU) coatings. The multifunctional vanillin–, imine–, phosphorus (VEDAP) compound involved a two-stage synthesis in which the first stage contained the imine formation by the reaction of vanillin (a biobased compound) and ethylenediamine (EDA). The latter stage continued with the incorporation of phosphorus moiety into the compound. The synthesized compound was incorporated into a commercial PU 2-pack formulation with different concentrations and coated onto the mild steel panels. The chemical structures of the intermediates were confirmed using Fourier-transform infrared (FTIR) spectroscopy, determination of the hydroxyl values, and nuclear magnetic resonance (NMR) spectroscopy. The thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) results revealed an increase in the degradation temperatures of the VEDAP containing coatings and the char yield. The heat resistance index temperatures (THRI) showed significant improvement in thermal stability with increasing concentration of VEDAP. The change in the coating formulations' crystallinity was studied using X-ray diffraction (XRD) method. The mechanical properties almost retained even for higher loading of VEDAP while biobased content apparently increased with increasing concentrations of VEDAP. The flame-retardant properties were checked using the limiting oxygen index (LOI) and UL-94 vertical burning test. The VEDAP has remarkably imparted flame retardancy with the highest LOI value of 29 with no dripping and self-extinguishing behavior within 10 s.