This work examines the physical and electrical breakdown characteristics of kenaf paper coated with Polyvinyl Alcohol (PVA) for application in power transformers. The paper was made from kenaf bast fibers using the soda pulping method, whereby the pulps were subjected to 12,000 beating revolutions. PVA with weight percentage concentration up to 6% was introduced to the beaten kenaf through a spin coating approach. The structure of the kenaf paper was examined through Scanning Electron Microscopy (SEM). The physical properties examined were apparent density, Tensile Index (TI), Burst Index (BI), and Tear Index (TeI), while AC breakdown voltage and strength were analyzed for the electrical property. It is found that the beating and external PVA improve the kenaf paper’s apparent density, TI, BI, and AC breakdown strength while the TeI decreases.

• Abdulkhani, A., Hojati Marvast, E., Ashori, A., Hamzeh, Y., & Karimi, A. N. (2013). Preparation of cellulose/polyvinyl alcohol biocomposite films using 1-n-butyl-3-methylimidazolium chloride. International Journal of Biological Macromolecules, 62, 379-386. https://doi.org/10.1016/j.ijbiomac.2013.08.050

• Afra, E., Mohammadnejad, S., & Saraeyan, A. (2016). Cellulose nanofibils as coating material and its effects on paper properties. Progress in Organic Coatings, 101, 455-460. https://doi.org/10.1016/j.porgcoat.2016.09.018

• Amin, N. A. M., Ishak, M. T., & Md Din, M. F. (2018). AC breakdown voltage and partial discharge of palm oil as insulating liquid with the presence of cellulose particles. [Paper presentation]. IEEE 7th International Conference on Power and Energy (PECon), Kuala Lumpur, Malaysia. https://doi.org/10.1109/PECON.2018.8684062

• Auhorn, W. J. (2006). Chemical additives. In H. Holik (Ed.), Handbook of Paper and Board (pp. 62-149). Wiley. https://doi.org/10.1002/3527608257.ch3

• Balan, T., Guezennec, C., Nicu, R., Ciolacu, F., & Bobu, E. (2015). Improving barrier and strength properties of paper by multi-layer coating with bio-based additives. Cellulose Chemistry and Technology, 49(8), 607-615.

• Bao, C., Guo, Y., Song, L., & Hu, Y. (2011). Poly (vinyl alcohol) nanocomposites based on graphene and graphite oxide: A comparative investigation of property and mechanism. Journal of Materials Chemistry, 21(36), 13942-13950. https://doi.org/10.1039/c1jm11662b

• Baur, M., Knauel, J., Calcara, L., & Pompili, M. (2017). Insulating liquids breakdown voltage determination: Test method efficiency. [Paper presentation]. 2017 IEEE 19th International Conference on Dielectric Liquids (ICDL), Manchester, United Kingdom. https://doi.org/10.1109/ICDL.2017.8124657

• Brännvall, E. (2009). Overview of pulp and paper processes. In M. Ek, G. Gellerstedt & G. Henriksson (Eds.), Pulping Chemistry and Technology (pp. 1-13). Walter de Gruyter. https://doi.org/10.1515/9783110213423

• Edeerozey, A. M. M., Akil, H. M., Azhar, A. B., & Ariffin, M. I. Z. (2007). Chemical modification of kenaf fibers. Materials Letters, 61(10), 2023-2025. https://doi.org/10.1016/j.matlet.2006.08.006

• Elanseralathan, K., Joy, T. M., & Nagabhushana, G. R. (2000). Breakdown of solid insulating materials under high frequency high voltage stress. [Paper presentation]. Proceedings of the IEEE International Conference on Properties and Applications of Dielectric Materials, Xi’an, China. https://doi.org/10.1109/icpadm.2000.876399

• Feng, D., Hao, J., Yang, L., Liao, R., Chen, X., & Li, J. (2020). Comparison of AC breakdown characteristics on insulation paper (pressboard) immersed by three-element mixed insulation oil and mineral oil. High Voltage, 5(3), 298-305. https://doi.org/10.1049/hve.2019.0103

• Finch, C. A. (Ed.). (1973). Polyvinyl Alcohol; Properties and Applications. John Wiley & Sons.

• Gao, W., Xiang, Z., Chen, K., Yang, R., & Yang, F. (2015). Effect of depth beating on the fiber properties and enzymatic saccharification efficiency of softwood kraft pulp. Carbohydrate Polymers, 127, 400-406. https://doi.org/10.1016/j.carbpol.2015.04.005

• Hammett, A. L., Youngs, R. L., Sun, X., & Chandra, M. (2001). Non-wood fiber as an alternative to wood fiber in China’s pulp and paper industry. Holzforschung, 55(2), 219-224. https://doi.org/10.1515/HF.2001.036

• Hubbe, M. (2006). Bonding between cellulosic fibers in the absence and presence of dry-strength agents – A review. BioResources, 1(2), 281-318. https://doi.org/10.15376/biores.1.2.281-318

• Huber, P., Lyannaz, L., & Carré, B. (2012). Specks masking by the coating layer in coated paper made from deinked pulp. Nordic Pulp and Paper Research Journal, 27(2), 466-471. https://doi.org/10.3183/NPPRJ-2012-27-02-p466-471

• Kamata, Y., Endoh, K., Furukawa, S., Endoh, F., Nonomura, K., Iwata, Y., Horiuchi, S., & Takasu, N. (1990). Dielectric strength of oil-immersed transformer insulation with Superimposed ac and lightning impulse voltage. IEEE Transactions on Electrical Insulation, 25(4), 683-687. https://doi.org/10.1109/14.57090

• Kamoga, O. L. M., Byaruhanga, J. K., & Kirabira, J. B. (2013). A review on pulp manufacture from non wood plant materials. International Journal of Chemical Engineering and Applications, 4(3), 144-148. https://doi.org/10.7763/ijcea.2013.v4.281

• Karlsson, H. (2010). Strength properties of paper produced from softwood kraft pulp – Pulp mixture, reinforcement and sheet stratification (Doctoral dissertation). Karlstad University, Sweden. http://www.diva-portal.org/smash/get/diva2:317178/FULLTEXT01.pdf

• Krause, C. (2012). Power transformer insulation - History, technology and design. IEEE Transactions on Dielectrics and Electrical Insulation, 19(6), 1941-1947. https://doi.org/10.1109/TDEI.2012.6396951

• Li, X., Li, J., Xiang, C., Zhang, J., Bao, L., & Ran, H. (2016). The influence of oil-impregnated insulation paper’s thickness on electrical breakdown strength. [Paper presentation]. IEEE Conference on Electrical Insulation and Dielectric Phenomena (CEIDP), Toronto, Canada. https://doi.org/10.1109/CEIDP.2016.7785511

• Liu, Z., Liu, Q., & Wang, Z. D. (2016). Effect of electric field configuration on streamer and partial discharge phenomena in a hydrocarbon insulating liquid under AC stress. Journal of Physics D: Applied Physics, 49(18), Article 185501. https://doi.org/10.1088/0022-3727/49/18/185501

• Lundgaard, L. E., Hansen, W., & Ingebrigtsen, S. (2008). Ageing of mineral oil impregnated cellulose by acid catalysis. IEEE Transactions on Dielectrics and Electrical Insulation, 15(2), 540-546. https://doi.org/10.1109/TDEI.2008.4483475

• Mathes, K. N. (1991). A brief history of development in electrical insulation. [Paper presentation]. Proceedings of the Electrical Electronics Insulation Conference, Boston, Massachusetts. https://doi.org/10.1109/eeic.1991.162590

• McShane, C. P., Corkran, J. L., Rapp, K. J., & Luksich, J. (2003). Aging of paper insulation retrofilled with natural ester dielectric fluid. [Paper presentation]. Annual Report Conference on Electrical Insulation and Dielectric Phenomena, New Mexico, USA. https://doi.org/10.1109/ceidp.2003.1254810

• Medhekar, N. V., Ramasubramaniam, A., Ruoff, R. S., & Shenoy, V. B. (2010). Hydrogen bond networks in graphene oxide composite paper: Structure and mechanical properties. ACS Nano, 4(4), 2300-2306. https://doi.org/10.1021/nn901934u

• Mo, Y., Yang, L., Zou, T., Hou, W., & Liao, R. (2019). Preparation of composite insulating paper with decreased permittivity, good mechanical and thermal properties by kevlar/nano cellulose fibrils/softwood pulp hybrid. IEEE Access, 7, 104258-104268. https://doi.org/10.1109/ACCESS.2019.2930981

• Moore, S., Rapp, K., & Baldyga, R. (2012). Transformer insulation dry out as a result of retrofilling with natural ester fluid. [Paper presentation]. Proceedings of the IEEE Power Engineering Society Transmission and Distribution Conference, Florida, USA. https://doi.org/10.1109/TDC.2012.6281441

• Ni, S., Liu, N., Fu, Y., Bian, H., Zhang, Y., Chen, X., Gao, H., & Dai, H. (2021). Laccase-catalyzed chitosan-monophenol copolymer as a coating on paper enhances its hydrophobicity and strength. Progress in Organic Coatings, 151, Article 106026. https://doi.org/10.1016/j.porgcoat.2020.106026

• Norrman, K., Ghanbari-Siahkali, A., & Larsen, N. B. (2005). 6 Studies of spin-coated polymer films. Annual Reports on the Progress of Chemistry - Section C, 101, 174-201. https://doi.org/10.1039/b408857n

• Nuruddin, M., Gupta, R., Tcherbi-Narteh, A., Hosur, M., & Jeelani, S. (2015, June 10-12). Thermal and mechanical properties of cellulose nanofibers reinforced polyvinyl alcohol composite films. [Paper presentation]. The 69th FPS International Convention. Atlanta, Georgia.

• Qu, G., Cui, H., Zhu, Y., Yang, L., & Li, S. (2020). Substantial improvement of the dielectric strength of cellulose-liquid composites: Effects of traps at the nanoscale interface. Journal of Physical Chemistry Letters, 11(5), 1881-1889. https://doi.org/10.1021/acs.jpclett.0c00235

• Ramli, M. R., Arief, Y. Z., Azli, S. A., Muhamad, N. A., Lau, K. Y., Farhan, M., Bashir, N., Mohd, N. K., Huey, L. W., & Kiat, Y. S. (2014). Partial discharge characteristics of palm fatty acid ester (PFAE) as high voltage insulating material. [Paper presentation]. The 2nd IEEE Conference on Power Engineering and Renewable Energy (ICPERE), Bali, Indonesia. https://doi.org/10.1109/ICPERE.2014.7067217

• Schaible, M. (1987). Electrical insulating papers - An overview. IEEE Electrical Insulation Magazine, 3(1), 8-12. https://doi.org/10.1109/MEI.1987.290616

• Schuman, T., Wikström, M., & Rigdahl, M. (2003). The effect of hot calendering of the substrate on the barrier properties of poly(vinyl alcohol)-coated papers. Nordic Pulp and Paper Research Journal, 18(1), 81-89. https://doi.org/10.3183/npprj-2003-18-01-p081-089

• Schuman, T., Wikström, M., & Rigdahl, M. (2004). Coating of surface-modified papers with poly(vinyl alcohol). Surface and Coatings Technology, 183(1), 96-105. https://doi.org/10.1016/j.surfcoat.2003.09.059

• Shokrieh, M. M., Mahmoudi, A., & Shadkam, H. R. (2015). Hybrid polyvinyl alcohol and cellulose fiber pulp instead of asbestos fibers in cement-based composites. Mechanics of Composite Materials, 51(2), 231-238. https://doi.org/10.1007/s11029-015-9494-7

• Song, R., Ino, H., & Kimura, T. (2009). Mechanical property of silk/bamboo composite paper for effective utilization of waste silk. Journal of Textile Engineering, 55(3), 85-90. https://doi.org/10.4188/jte.55.85

• Umair, M., Azis, N., Halis, R., & Jasni, J. (2019). Investigation on the effect of beating on the physical and mechanical properties of untreated kenaf based insulation paper. [Paper presentation]. IEEE 5th International Conference on Smart Instrumentation, Measurement and Application (ICSIMA), Songkhla, Thailand https://doi.org/10.1109/ICSIMA.2018.8688758

• Umair, M., Azis, N., Halis, R., & Jasni, J. (2020). Investigation of kenaf paper in the presence of pva for transformers application. Materials, 13(21), 1-23. https://doi.org/10.3390/ma13215002

• Wai, N. N., Nanko, H., & Murakami, K. (1985). A morphological study on the behavior of bamboo pulp fibers in the beating process. Wood Science and Technology, 19(3), 211-222. https://doi.org/10.1007/BF00392050

• Wistara, N., & Young, R. A. (1999). Properties and treatments of pulps from recycled paper. Part I. Physical and chemical properties of pulps. Cellulose, 6(4), 291-324. https://doi.org/10.1023/A:1009221125962

• Yenidoğan, S. (2019). Nanocrystalline cellulose and polyvinyl alcohol coating application to cardboard packaging papers and investigation of the effects on paper properties. Medziagotyra, 26(3), 317-322. https://doi.org/10.5755/j01.ms.26.3.21499

• Zhang, P., Wang, Q., Guo, R., Zhang, M., Wang, S., Lu, C., Xue, M., Fan, J., He, Z., & Rao, W. (2019). Self-assembled ultrathin film of CNC/PVA-liquid metal composite as a multifunctional Janus material. Materials Horizons, 6(8), 1643-1653. https://doi.org/10.1039/c9mh00280d

• Zhou, C., & Chen, G. (2017). Space charge and AC electrical breakdown strength in polyethylene. IEEE Transactions on Dielectrics and Electrical Insulation, 24(1), 559-566. https://doi.org/10.1109/TDEI.2016.005811