Skip to content
Licensed Unlicensed Requires Authentication Published by De Gruyter May 10, 2022

Effect of expansion temperature on the properties of expanded graphite and modified linear low density polyethylene

Xiuyan Pang, Wenyu Zhang, Yafang Meng, Meifang Ma and Jianzhong Xu

Abstract

To study the influence of expansion temperature on the properties of expanded graphite (EBG), EBG300, EBG600, and EBG900 were prepared by heating expandable graphite (EG) at 300, 600, and 900 °C, respectively. Furthermore, the influence of these EBGs on the combustion performance and physical-mechanical properties of linear low density polyethylene (LLDPE) were investigated. The expansion volumes of EBG300, EBG600, and EBG900 increase with the rise of temperature, and a four-stage ordered structure of “graphite worm” gradually forms. The thermal stability increases gradually for EBG300, EBG600, and EBG900. On the contrary, the thermal conductivity decreases in sequence. However, the incorporation of EBG900 promotes the formation of a continuous network structure and makes the modified LLDPE to present the best heat transmission. The addition of 30 wt% of these EBGs significantly improves LLDPE’s flame retardancy and high-temperature thermal stability. The total heat release, the peak value of heat release rate, and the fire growth index of 70LLDPE/30EBG300 reduce by 69, 91, and 87% respectively, while the effective fire performance index improves seven times. The addition of these additives reduces the tensile strength and elongation at break, the larger the EBG size, the more obvious the effect.


Corresponding author: Xiuyan Pang, College of Chemistry and Environmental Science, Hebei University, Wusi East Road No. 180, Baoding, 071002, P. R. China; and Flame Retardant Material and Processing Technology Engineering Technology Research Center of Hebei Province; Key Laboratory of Analytical Science and Technology of Hebei Province, Hebei University, Baoding, P. R. China, E-mail:

Funding source: Natural Science Foundation of Hebei Province

Award Identifier / Grant number: B2015201028

  1. Author contributions: All the authors have accepted responsibility for the entire content of this submitted manuscript and approved submission.

  2. Research funding: This study was supported by project (No. B2015201028) of Natural Science Foundation of Hebei Province, P R China. We gratefully acknowledge the support.

  3. Conflict of interest statement: The authors declare no conflicts of interest regarding this article.

References

Akdogan, E., Erdem, M., Erdem Ureyen, M., and Kaya, M. (2020). Synergistic effects of expandable graphite and ammonium pentaborate octahydrate on the flame-retardant, thermal insulation, and mechanical properties of rigid polyurethane foam. Polym. Compos. 41: 1749–1762, https://doi.org/10.1002/pc.25494.Search in Google Scholar

Arslan, F. and Dilsiz, N. (2020). Flame resistant properties of LDPE/PLA blends containing halogen-free flame retardant. J. Appl. Polym. Sci. 137: 48960, https://doi.org/10.1002/app.48960.Search in Google Scholar

Ban, D.M., Chen, S.M., Li, P., and Lai, F. (2018). The relationship between structure and thermal property of two bisphenol A-derived polyphosphates. Polym. Bull. 75: 5103–5112, https://doi.org/10.1007/s00289-018-2318-x.Search in Google Scholar

Çalın, Ö., Kurt, A., and Çelik, Y. (2020). Influence of expansion conditions and precursor flake size on porous structure of expanded graphite. Fullerenes, Nanotub. Carbon Nanostruct. 28: 611–620, https://doi.org/10.1080/1536383X.2020.1726894.Search in Google Scholar

Chan, Y.Y., Chao, M., Feng, Z., Yuan, H., and Bernhard, S. (2022). A liquid phosphorous flame retardant combined with expandable graphite or melamine in flexible polyurethane foam. Polym. Adv. Technol. 33: 326–339, https://doi.org/10.1002/pat.5519.Search in Google Scholar

Chen, Y.J., Luo, Y.F., Guo, X.H., Chen, L.J., and Jia, D.M. (2020). The synergistic effect of ionic liquid-modified expandable graphite and intumescent flame-retardant on flame-retardant rigid polyurethane foams. Materials 13: 3095, https://doi.org/10.3390/ma13143095.Search in Google Scholar PubMed PubMed Central

Do, Q.C., Choi, S., Kim, H., and Kang, S. (2019). Adsorption of lead and nickel on to expanded graphite decorated with manganese oxide nanoparticles. Appl. Sci. 9: 5375, https://doi.org/10.3390/app9245375.Search in Google Scholar

Faghidian, S.A. (2020a). Higher order mixture nonlocal gradient theory of wave propagation. Math. Methods Appl. Sci.: 1–23, https://doi.org/10.1002/mma.6885.Search in Google Scholar

Faghidian, S.A. (2020b). Two-phase local/nonlocal gradient mechanics of elastic torsion. Math. Methods Appl. Sci.: 1–17, https://doi.org/10.1002/mma.6877.Search in Google Scholar

Faghidian, S.A. (2021a). Flexure mechanics of nonlocal modified gradient nano-beams. J. Comput. Des. Eng. 8: 949–959, https://doi.org/10.1093/jcde/qwab027.Search in Google Scholar

Faghidian, S.A. (2021b). Contribution of nonlocal integral elasticity to modified strain gradient theory. Eur. Phys. J. Plus 136: 559, https://doi.org/10.1140/epjp/s13360-021-01520-x.Search in Google Scholar

Faghidian, S.A., Zur, K.K., and Reddy, J.N. (2022). A mixed variational framework for higher-order unified gradient elasticity-Science Direct. Int. J. Eng. Sci. 170: 103603, https://doi.org/10.1016/j.ijengsci.2021.103603.Search in Google Scholar

Gulnura, N., Kenes, K., Yerdos, O., Zulkhair, M., and Di Capua, R. (2018). Preparation of expanded graphite using a thermal method. Mater. Sci. Eng. 323: 012012, https://doi.org/10.1088/1757-899X/323/1/012012.Search in Google Scholar

Hermanus Joachim, K., Walter Wilhelm, F., Washington, M., Albertus, T., and Albert, R. (2017). Thermal properties of polyethylene flame retarded with expandable graphite and intumescent fire retardant additives. Fire Mater. 41: 573–586, https://doi.org/10.1002/fam.2387.Search in Google Scholar

Huang, J.D., Tang, Q.Q., Liao, W.B., Wang, G.C., Wei, W., and Li, C.Z. (2017). Green preparation of expandable graphite and its application in flame-resistance polymer elastomer. Ind. Eng. Chem. Res. 56: 5253–5261, https://doi.org/10.1021/acs.iecr.6b04860.Search in Google Scholar

Lee, H.I., Kim, W.J., Heo, Y.J., Son, Y.R., and Park, S.J. (2018). Control of interlayer spacing of expanded graphite for improved hydrogen storage capacity. Carbon Lett. 27: 117–120, https://doi.org/10.5714/CL.2018.27.117.Search in Google Scholar

Li, J., Mo, X., Li, Y., Zou, H., Liang, M., and Chen, Y. (2018a). Influence of expandable graphite particle size on the synergy flame retardant property between expandable graphite and ammonium polyphosphate in semi-rigid polyurethane foam. Polym. Bull. 75: 5287–5304, https://doi.org/10.1007/s00289-018-2309-y.Search in Google Scholar

Li, L.J., Chen, Y.J., Qian, L.J., Xu, B., and Xi, W. (2018b). Addition flame-retardant effect of nonreactive phosphonate and expandable graphite in rigid polyurethane foams. J. Appl. Polym. Sci. 135: 45960, https://doi.org/10.1002/app.45960.Search in Google Scholar

Li, L.T., Wang, D.Z., Chen, S.P., Zhang, Y.Y., Wu, Y.F., Wang, N., Chen, X.L., Qin, J., Zhang, K., and Wu, H. (2020). Effect of organic grafting expandable graphite on combustion behaviors and thermal stability of low-density polyethylene composites. Polym. Compos. 41: 719–728, https://doi.org/10.1002/pc.25401.Search in Google Scholar

Li, Y., Jing, Z., Zhou, S.T., Chen, Y., Zou, H.W., Liang, M., and Luo, W.Z. (2014). Effect of expandable graphite particle size on the flame retardant, mechanical, and thermal properties of water-blown semi-rigid polyurethane foam. J. Appl. Polym. Sci. 131: 1082–1090, https://doi.org/10.1002/app.39885.Search in Google Scholar

Liu, J.N., Pang, X.Y., Shi, X.Z., and Xu, J.Z. (2020). Expandable graphite in polyethylene: the effect of modification, particle size and the synergistic effect with ammonium polyphosphate on flame retardancy, thermal stability and mechanical properties. Combust. Sci. Technol. 192: 575–591, https://doi.org/10.1080/00102202.2019.1584797.Search in Google Scholar

Liu, S.H., Zhu, J.H., and Wang, Z.X. (2017a). Research progress of thermally conductive composites filled with different forms of fillers. Dev. Appl. Mater. (Chinese) 31: 99–102, https://doi.org/10.19515/j.cnki.1003-1545.2017.01.018.Search in Google Scholar

Liu, T., Zhang, R.J., Zhang, X.S., Liu, K., Liu, Y.Y., and Yan, P.T. (2017b). One-step room-temperature preparation of expanded graphite. Carbon 2019: 544–547, https://doi.org/10.1016/j.carbon.2017.04.076.Search in Google Scholar

Liu, Z.Q., Hao, Y.S., Su, Y.J., Wei, Y.J., Wang, J.Y., Yan, H., Shen, W.C., Huang, Z.H., Wang, X.M., and Zhao, L.Y. (2019). A novel and facile prepared wound dressing based on large expanded graphite worms. J. Mater. Res. 34: 490–499, https://doi.org/10.1557/jmr.2018.473.Search in Google Scholar

Long, J.P., Li, S.X., and Liang, B. (2018). Synthesis and properties of a new halogen-free flame retardant for polyethylene. Pigm. Resin Technol. 47: 208–215, https://doi.org/10.1108/PRT-04-2016-0048.Search in Google Scholar

Lorenzetti, A., Dittrich, B., and Schartel, B. (2017). Expandable graphite in polyurethane foams: the effect of expansion volume and intercalants on flame retardancy. J. Appl. Polym. Sci. 134: 45173, https://doi.org/10.1002/app.45173.Search in Google Scholar

Lv, X.Y., Zeng, W., Yang, Z.W., Yang, Y.X., Wang, Y., Lei, Z.Q., Liu, J.L., and Chen, D.L. (2020). Fabrication of ZIF-8@polyphosphazene core-shell structure and its efficient synergism with ammonium polyphosphate in flame-retarding epoxy resin. Polym. Adv. Technol. 31: 997–1006, https://doi.org/10.1002/pat.4834.Search in Google Scholar

Ma, M.F., Pang, X.Y., and Chang, R. (2019). Enhancing flame retardancy, thermal stability, physical and mechanical properties of polyethylene foam with polyphosphate modified expandable graphite and ammonium polyphosphate. Int. Polym. Proc. 34: 239–247, https://doi.org/10.3139/217.3714.Search in Google Scholar

Pang, X.Y., Shi, X.Z., Kang, X.O., Duan, M.W., and Weng, M.Q. (2016). Preparation of borate-modified expandable graphite and its flame retardancy on acrylonitrile-butadiene-styrene resin. Polym. Compos. 37: 2673–2683, https://doi.org/10.1002/pc.23461.Search in Google Scholar

Pang, X.Y., Tian, Y., Duan, M.W., and Zhai, M. (2013). Preparation of low initial expansion temperature expandable graphite and its flame retardancy for LLDPE. Cent. Eur. J. Chem. 11: 953–959, https://doi.org/10.2478/s11532-013-0227-2.Search in Google Scholar

Pang, X.Y., Tian, Y., and Weng, M.Q. (2017). Preparation of expandable graphite with silicate assistant intercalation and its effect on flame retardancy of ethylene vinyl acetate composites. Polym. Compos. 36: 1407–1416, https://doi.org/10.1002/pc.23047.Search in Google Scholar

Pang, X.Y., Xin, Y.P., Shi, X.Z., and Xu, J.Z. (2019). Effect of different size-modified expandable graphite and ammonium polyphosphate on the flame retardancy, thermal stability, physical, and mechanical properties of rigid polyurethane foam. Polym. Eng. Sci. 59: 1381–1394, https://doi.org/10.1002/pen.25123.Search in Google Scholar

Peng, T.F., Liu, B., Gao, X.C., Luo, L.Q., and Sun, H.J. (2018). Preparation, quantitative surface analysis, intercalation characteristics and industrial implications of low temperature expandable graphite. Appl. Surf. Sci. 444: 800–810, https://doi.org/10.1016/j.apsusc.2018.03.089.Search in Google Scholar

Pham, T.V., Nguyen, T.T., Nguyen, D.T., Thuan, T.V., Bui, P.Q.T., Viet, V.N.D., and Bach, L.G. (2019). The preparation and characterization of expanded graphite via microwave irradiation and conventional heating for the purification of oil contaminated water. J. Nanosci. Nanotechnol. 19: 1122–1125, https://doi.org/10.1166/jnn.2019.15926.Search in Google Scholar

Shioyama, H. and Fujii, R. (1987). Electrochemical reactions of stage-1 sulfuric acid graphite intercalation compound. Carbon 25: 771–774, https://doi.org/10.1016/0008-6223(87)90149-7.Search in Google Scholar

Sobolciak, P., Abdulgader, A., Mrlik, M., Popelka, A., Abdala, A.A., Aboukhlewa, A.A., and Krupa, I. (2020). Thermally conductive polyethylene/expanded graphite composites as heat transfer surface: mechanical, thermo-physical and surface behavior. Polymers 12: 2863, https://doi.org/10.3390/polym12122863.Search in Google Scholar PubMed PubMed Central

Sorokina, N.E., Khaskov, M.A., Avdeev, V.V., and Nikol’Skaya, I.V. (2005). Reaction of graphite with sulfuric acid in the presence of KMnO4. Russ. J. Gen. Chem. 75: 162–168, https://doi.org/10.1007/s11176-005-0191-4.Search in Google Scholar

Tang, M.Q., Chen, M., Xu, Y., Chen, X.L., Sun, Z.D., and Zhang, Z.B. (2015). Combustion characteristics and synergistic effects of red phosphorus masterbatch with expandable graphite in the flame retardant HDPE/EVA composites. Polym. Eng. Sci. 55: 2884–2892, https://doi.org/10.1002/pen.24180.Search in Google Scholar

Tian, N.N., Gong, J., Wen, X., Yao, K., and Tang, T. (2014). Synthesis and characterization of a novel organophosphorus oligomer and its application in improving flame retardancy of epoxy resin. RSC Adv. 4: 17607–17614, https://doi.org/10.1039/c4ra01525h.Search in Google Scholar

Wang, B., Hu, S., Zhao, K., Lu, H., Song, L., and Hu, Y. (2011). Preparation of polyurethane microencapsulated expandable graphite, and its application in ethylene vinyl acetate copolymer containing silica-gel microencapsulated ammonium polyphosphate. Ind. Eng. Chem. Res. 50: 11476–11484, https://doi.org/10.1021/ie200886e.Search in Google Scholar

Wang, M.L. and Ji, L. (2012). Expansion mechanism of expandable graphite formed by natural graphite with different particle size. Adv. Mater. Res. 499: 16–19, https://doi.org/10.4028/www.scientific.net/AMR.499.16.Search in Google Scholar

Wang, N., Xu, G., Wu, Y.H., Zhang, J., Hu, L.D., Luan, H.H., and Fang, Q.H. (2016). The influence of expandable graphite on double-layered microcapsules in intumescent flame-retardant natural rubber composites. J. Therm. Anal. Calorim. 123: 1239–1251, https://doi.org/10.1007/s10973-015-5011-4.Search in Google Scholar

Weidenfeller, B., Höfer, M., and Schilling, F.R. (2004). Thermal conductivity, thermal diffusivity, and specific heat capacity of particle filled polypropylene. Composites, Part A 35: 423–429, https://doi.org/10.1016/j.compositesa.2003.11.005.Search in Google Scholar

Wu, Z.P., Shu, W.Y., Xiong, L.M., and Huang, K.Y. (2004). Study of ammonium polyphosphate synthesis and its flame tetardation. J. Cent. S. For. Univ. (Chinese) 24: 41–43.Search in Google Scholar

Xu, C.B., Jiao, C.L., Yao, R.H., Lin, A.J., and Jiao, W.T. (2018). Adsorption and regeneration of expanded graphite modified by CTAB-KBr/H3PO4 for marine oil pollution. Environ. Pollut. 233: 194–200, https://doi.org/10.1016/j.envpol.2017.10.026.Search in Google Scholar PubMed

Yang, G.C., Cai, J.R., Geng, Y.R., Xu, B.B., and Zhang, Q.H. (2020). Cu-modified ZSM zeolite has synergistic flame retardance, smoke suppression, and catalytic conversion effects on pulp fiber after ammonium polyphosphate flame-retardant treatment. ACS Sustain. Chem. Eng. 8: 14365–14376, https://doi.org/10.1021/acssuschemeng.0c03920.Search in Google Scholar

Yang, J.J., Chen, X.H., Zhou, H.L., Guo, W.C., Zhang, J., Miao, Z., and He, D.H. (2022). Synergistic effect of expandable graphite and aluminum hypophosphite in flame-retardant ethylene vinyl acetate composites. Polym. Adv. Technol. 33: 638–646, https://doi.org/10.1002/pat.5546.Search in Google Scholar

Zhao, H.M., Pang, X.Y., and Lin, R.N. (2016). Preparation of boric acid modified expandable graphite and its influence on polyethylene combustion characteristics. J. Chil. Chem. Soc. 61: 2767–2771, https://doi.org/10.4067/S0717-97072016000100004.Search in Google Scholar

Zhao, H., Zhou, W., Shen, W.C., and Kang, F.Y. (2002). Pore structure of exfoliated graphite and its varieties of liquid sorption. Mater. Sci. Eng. (Chinese) 20: 153–159, https://doi.org/10.14136/j.cnki.Search in Google Scholar

Zhao, M. and Liu, P. (2009). Adsorption of methylene blue from aqueous solutions by modified expanded graphite powder. Desalination 249: 331–336, https://doi.org/10.1016/j.desal.2009.01.037.Search in Google Scholar

Zhou, Y., Sun, W.C., Ling, Z.Y., Fang, X.M., and Zhang, Z.G. (2017). Hydrophilic modification of expanded graphite to prepare a high-performance composite phase change block containing a hydrate salt. Ind. Eng. Chem. Res. 56: 14799–14806, https://doi.org/10.1021/acs.iecr.7b03986.Search in Google Scholar

Received: 2022-01-04
Accepted: 2022-04-11
Published Online: 2022-05-10
Published in Print: 2022-07-26

© 2022 Walter de Gruyter GmbH, Berlin/Boston