Flame-Retardant Wood Composites Based on Immobilizing with Chitosan/Sodium Phytate/Nano-TiO2-ZnO Coatings via Layer-by-Layer Self-Assembly

Abstract

Composite coatings of inorganic nanomaterials with polyelectrolytes are promising materials for wood modification. Endowing wood with flame retardancy behavior can not only broaden the range of applications of wood, but also improve the safety of wood products. In this work, chitosan/sodium phytate/TiO2-ZnO nanoparticle (CH/SP/nano-TiO2-ZnO) composite coatings were coated on wood surface through layer-by-layer self-assembly. The morphology and chemical composition of the modified wood samples were analyzed using scanning electron microscopy and energy dispersive spectrometry. The thermal degradation properties and flame retardancy of the samples treated with different assembly structures were observed by thermogravimetric analysis, limiting oxygen test, and combustion test. Due to the presence of an effective intumescent flame retardant system and a physical barrier, the CH/SP/nano-TiO2-ZnO coatings exhibited the best flame retardant performance and required only approximately six seconds for self-extinguishing. The coated samples had a limiting oxygen index of 8.4% greater than the original wood.

Potential Use of Wollastonite as a Filler in UF Resin Based Medium-Density Fiberboard (MDF)

“…Many minerals have been added to resins as reinforcing fillers to improve the composite properties [ 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 ]. Silicate minerals have been shown to enhance the thermal conductivity in oriented strandboard, thereby reducing the potential energy [ 19 , 20 , 21 , 22 ].…”

Flame-Retardant Systems Based on Chitosan and Its Derivatives: State of the Art and Perspectives

“…To the best of the authors’ knowledge, the scientific literature reports only one very recent paper dealing with the use of chitosan as a component of flame retardant recipes for wood. In particular, Zhou and Fu [ 57 ] exploited the Layer-by-Layer technique for depositing assemblies made of chitosan, sodium phytate and TiO 2 -ZnO nanoparticles, according to the scheme shown in Figure 31 . In order to achieve a homogeneous coverage of the underlying substrate, 10 deposition cycles were performed, and for comparison, aiming at investigating the effect of a single component of the LbL architectures, wood was also coated with assemblies made of (i) chitosan, (ii) chitosan and sodium phytate, (iii) chitosan, sodium phytate and nano-TiO 2 , or (iv) chitosan, sodium phytate and nano-ZnO.…”

“…CH: Chitosan-coated (green); CH/SP: chitosan sodium phytate-coated (purple); CH/SP/nano-ZnO: chitosan/sodium phytate/nano-ZnO-coated (yellow); CH/SP/nano-TiO 2 : chitosan/sodium phytate/nano-TiO 2 -coated (blue); CH/SP/nano-TiO 2 -ZnO: chitosan/sodium phytate/nano-TiO 2 -ZnO-coated. Reprinted from [ 57 ] under CC BY 4.0 license.…”

“… Propensity for flame burning of wood and the coated samples: ( a1 , a2 ) original wood; ( b1 , b2 ) chitosan-coated sample; ( c1 , c2 ) chitosan sodium phytate-coated sample; ( d1 , d2 ) chitosan/sodium phytate/nano-ZnO-coated sample; ( e1 , e2 ) chitosan/sodium phytate/nano-TiO 2 -coated sample; ( f1 , f2 ) chitosan/sodium phytate/nano-TiO 2 -ZnO-coated sample. Reprinted from [ 57 ] under CC BY 4.0 license. …”

Effect of MF-Coated Epoxy Resin Microcapsules on Properties of Waterborne Wood Coating on Basswood

“…Today, microcapsule technology has been used in more and more fields. In the wood coating process [3,4], the waterborne coatings can reduce VOC (volatile organic compound) emissions and are therefore more environmentally friendly [5,6]. Still, cracking defects are likely to occur in the coating and subsequent use process, resulting in reduced mechanical properties, so self-healing microcapsule technology can be used to repair the cracks [7].…”