Effects of fire-retardant additives for acrylic coating on flame-retardancy of painted poplar wood

Document Type : Complete scientific research article

Authors

1 Master's student in wood conservation and improvement, Gorgan University of Agricultural Sciences and Natural Resources, Gorgan, Iran.

2 Assistant Professor, Department of Wood Technology and Engineering, Gorgan University of Agricultural Sciences and Natural Resources, Gorgan, Iran.

3 Professor, Department of Wood Technology and Engineering, Gorgan University of Agricultural Sciences and Natural Resources, Gorgan, Iran.

4 Associate Professor, Department of Wood Technology and Engineering, Gorgan University of Agricultural Sciences and Natural Resources, Gorgan, Iran.

Abstract

Background and objectives: Wood, as a renewable and environmentally friendly material, possesses unique mechanical, physical, and aesthetic properties that make it widely used in the construction, furniture, and decorative industries. However, wood is susceptible to degradation by various factors such as biological agents, weathering, and fire. Extensive efforts have been made to enhance the durability of wood, including the use of paints for protection against weathering and moisture. However, both wood and polymer-based paints are flammable. To address this issue, flame retardant materials have been incorporated into paint formulations to reduce flammability. This study aims to investigate the effects of flame retardants on the fire resistance and color changes of acrylic coatings applied to pine wood.
Materials and methods: In this research, the impact of flame retardant materials (zinc borate, di ammonium phosphate, nanosilica, and nanoclay) at concentrations of 10% and 20%, as well as their binary combinations (20%), in the structure of acrylic paint was examined for their fire resistance on colored pine wood. Subsequently, the tensile strength of the paint film, color changes of the wood samples, and their fire resistance were analyzed.
Results: The results of this investigation indicate that zinc borate and di ammonium phosphate did not have a discernible effect on the tensile strength of the paint film. However, the incorporation of nanoclay significantly increased the film's tensile strength, while the addition of nanosilica led to a notable decrease in this property. Among the tested samples, those containing zinc borate and di ammonium phosphate exhibited the least significant color changes. The introduction of flame retardant materials into the paint formulation resulted in improved fire resistance, with ammonium phosphate and nanoclay exhibiting superior performance in this regard. Importantly, there were no substantial differences observed between the 10% and 20% concentrations of the flame retardant materials across many of the conducted tests. Notably, the combination treatments of di ammonium phosphate-zinc borate and di ammonium phosphate-nanoclay demonstrated more effective outcomes concerning color changes and fire resistance.
Conclusion: The findings of this study reveal that di ammonium phosphate and zinc borate had the least detrimental effects on the tensile strength of the paint film and the color changes observed in both the wood samples and the paint film. Furthermore, these two flame retardant materials exhibited superior performance in enhancing fire resistance. Therefore, it is strongly recommended to incorporate di ammonium phosphate and zinc borate as flame retardants in acrylic paint formulations specifically intended for use on wood surfaces

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  1. 1.Kmeťová, E., Kačík, F., Kubovský, I., & Kačíková, D. (2022). Effect of expandable graphite flakes on the flame resistance of oak wood. Coatings. 12 (12), 1908.

    2.Akbarnezhad, M., Rasouli, D., Yousefi, H., & Mashkour, M. (2020). Weathering performance of beech wood coated with acrylic paint containing UV stabilizers of dihydroxy benzophenone and nano zinc oxide. Drvna Industrija. 71 (4), 403-409.

    3.Chuang, C. S., Tsai, K. C., Yang, T. H., Ko, C. H., & Wang, M. K. (2011). Effects of adding organo-clays for acrylic-based intumescent coating on fire-retardancy of painted thin plywood. Applied Clay Science. 53 (4), 709-715.

    4.Shah, A. U. R., Prabhakar, M., & Song, J. (2017). Current advances in the fire retardancy of natural fiber and bio-based composites–A review. International J. of Precision Engineering and Manufacturing- Green Technology. 4, 247-262.

    5.Bee, S. T., Sin, L. T., Cheng, B. S., Ratnam, C. T., & Rahmat, A. (2018). Electron beam irradiation of zinc borate flame retardant containing acrylonitrile-butadiene-styrene ABS composites. J. of Polymer Research. 25, 1-16.

    6.Yan, L., Xu, Z., & Wang, X. (2019). Synergistic flame-retardant and smoke suppression effects of zinc borate in transparent intumescent fire-retardant coatings applied on wood substrates. J. of Thermal Analysis and Calorimetry. 136, 1563-1574.

    7.Tang, S., Qian, L., Qiu, Y., & Dong, Y. (2018). Synergistic flame‐retardant effect and mechanisms of boron/phosphorus compounds on epoxy resins. Polymers for Advanced Technologies. 29 (1), 641-648.

    8.Rangavar, H., Khosro, S., & Javy, M. (2018). The effect of nano wollastonite on the fire resistance and the adhesion properties of the water-based acrylic coating on wood surfaces. Iranian J. of Wood and Paper Science Research. 3, 2.

    9.Tian, Y., Wang, C., Ai. Y., Tang, L., & Cao, K. (2023). Phytate-based transparent and waterproof intumescent flame-retardant coating for protection of wood. Materials Chemistry and Physics. 294, 127000.

    10.Standard British 476. (1991). Fire tests on buildingmaterials andstructures. Part 12: Method of test for ignitability of products by direct flame impingement.

    1. 11. Wang, Z., Han, E., & Ke, W. (2006). Effect of acrylic polymer and nanocomposite with nano-SiO2
      on thermal degradation and fire resistance of APP–DPER–MEL coating. Polymer Degradation and Stability.
      91 (9), 1937-1947.
    2. 12. Albdiry, M., Yousif, B., Ku, H., & Lau, K. (2013). A critical review on the manufacturing processes in relation to the properties of nanoclay/polymer composites. of Composite Materials. 47 (9), 1093-1115.
    3. 13. Drevelle, C., Duquesne, S., Le Bras, M., Lefebvre, J., Delobel, R., Castrovinci, A., & Vouters, M. (2004). Influence of ammonium polyphosphate on the mechanism of thermal degradation of an acrylic binder resin. of Applied Polymer Science. 94 (2), 717-729.
    4. 14. Duquesne, S., Magnet, S., Jama, C., & Delobel, R. (2005). Thermoplastic resins for thin film intumescent coatings–towards a better understanding of their effect on intumescence efficiency. Polymer Degradation and Stability.
      88 (1), 63-69.
    5. 15. Xiong, M., Wu, L., Zhou, S., & You, B. (2002). Preparation and characterization of acrylic latex/nano-SiO2 Polymer International. 51 (8), 693-698.
    6. 16. Lu, N., Zhang, P., Wu, Y.n., Zhu, D., & Pan, Z. (2019). Effects of size of zinc borate on the flame retardant properties of intumescent coatings. International J. of Polymer Science.
    7. 17. Yan, L., Xu, Z., & Wang, X. (2018). Synergistic effects of organically modified montmorillonite on the flame-retardant and smoke suppression properties of transparent intumescent fire-retardant coatings. Progress in Organic Coatings. 122, 107-118.