Analysis of Factors Influencing Mechanical Properties of Recycled Polypropylene/Tea Waste Composites Using Factorial Experimental Design
Main Article Content
Abstract
This study aimed to analyze the influence of key factors on the mechanical properties of recycled polypropylene/tea waste composites using a General Factorial Design experiment. The research evaluated the effects of tea waste type (Thai tea and green tea), polypropylene- graft-maleic anhydride (PP-g-MA) content, and thermoplastic elastomer (TPE) content on yield strength, tensile strength, elastic modulus, elongation percentage, impact strength, and hardness. Analysis of Variance (ANOVA) and quantitative effect analysis revealed that all three factors had statistically significant impacts on the composites' mechanical properties. Specifically, tea waste type significantly influenced hardness and elastic modulus, while PP-g-MA positively affected the yield strength, tensile strength and elastic modulus, and TPE enhanced impact strength and elongation percentage.
The contour plot analysis provided insights into the relationship between factors and mechanical properties, aligning with the main effects analysis results. No significant interactions were found between tea waste types and PP-g-MA or TPE content for most mechanical properties, except for elastic modulus and hardness. Regression coefficient analysis and linear regression for mechanical properties prediction showed moderate predictive capability, with determination coefficients ranging from 47.29% to 67.77%. Using the desirability function optimization method, the formulation containing green tea waste and 5% PP-g-MA without TPE achieved the highest composite desirability of 0.90, indicating the best balance of mechanical properties. Although adding 5% TPE significantly improved impact resistance and elongation percentage, it reduced the maximum tensile strength. This research suggests that the material is suitable for applications not requiring high strength, making it appropriate for furniture manufacturing or home decoration such as garden and landscape decoration, wall or ceiling panels, and shelves or storage cabinets with light load-bearing requirements.
Article Details

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.
The content and information in articles published in the Journal of Advanced Development in Engineering and Science are the opinions and responsibility of the article's author. The journal editors do not need to agree or share any responsibility.
Articles, information, content, etc. that are published in the Journal of Advanced Development in Engineering and Science are copyrighted by the Journal of Advanced Development in Engineering and Science. If any person or organization wishes to publish all or any part of it or to do anything. Only prior written permission from the Journal of Advanced Development in Engineering and Science is required.
References
Ramesh, M., et al. (2022). A Critical Review on Wood-Based Polymer Composites: Processing, Properties, and Prospects. Polymers, 14(3), 589.
Zhou, Y., et al. (2019). A Circular Economy Use of Recovered Sludge Cellulose in Wood Plastic Composite Production: Recycling and Eco-Efficiency Assessment. Waste Management, 99, 42–48.
Khongrit, A., et al. (2016). Effect of Coupling Agent on Mechanical Properties Effect of Coupling Agent on Mechanical Properties. SWU Engineering Journal, 11(2), 57-66. (in Thai)
Nithikarnjanatharn, J. & Khongrit, A. (2019). Effect of Crosslinking Agents and Sauna Periods in Crosslinking Process on Mechanical and Physical Properties of Recycled Polyoxymethylene. UBU Engineering Journal. 12(2), 49-62. (in Thai)
Campos-Vega, R., et al. (2015) Spent Coffee Grounds: A Review on Current Research and Future Prospects. Trends in Food Science & Technology. 54, 24−36.
Khongrit, A. & Nithikarnjanatharn, J. (2018). Effect of Compatibilizing Agents on Mechanical and Physical Properties of Spent Coffee Ground Filled Polypropylene Composites. UBU Engineering Journal. 11(1), 18-28. (in Thai)
Nithikarnjanatharn, J. & Khongrit, A. (2020). Effects of Coupling Agent on Mechanical and Physical Properties of Spent Coffee Ground Filled with Polylactic Acid Composites. UBU Engineering Journal. 13(2), 64-76. (in Thai)
Rijo, B., et al. (2021). Catalyzed Pyrolysis of Coffee and Tea Wastes. Energy, 235, 121252.
Ballesteros, L. F., et al. (2014). Chemical, Functional, and Structural Properties of Spent Coffee Grounds and Coffee Silverskin. Food and Bioprocess Technology, 7(12), 3493–3503.
Khongrit, A., et al. (2022). A Preliminary Study on Composites from Recycled Grade Polypropylene Mixed with Spent Tea. Rangsit University Journal of Engineering and Technology, 25(2), 43-56. (in Thai)
Jubinville, D., et al. (2022). Simulated Recycling of Polypropylene and Maleated Polypropylene for the Fabrication of Highly-Filled Wood Plastic Composites. ACS Applied Polymer Materials, 4(4), 2373–2383.
Burgada, F., et al. (2021). Upgrading Recycled Polypropylene from Textile Wastes in Wood Plastic Composites with Short Hemp Fiber. Polymers, 13(8), 1248.
Sbrescia, S., et al. (2022). Molecular Weight Effects on the Stress-Relaxation Behavior of Soft Thermoplastic Elastomer by Means of Temperature Scanning Stress Relaxation (TSSR). Journal of Rheology, 66(6), 1321–1330.
Torres, V. M., et al. (2021). Controlling Nanostructure and Mechanical Properties in Triblock Copolymer/Monomer Blends Via Reaction-Induced Phase Transitions. Soft Matter, 17(6), 1505–1512.
Saleem, M. M., & Somà, A. (2015). Design of Experiments Based Factorial Design and Response Surface Methodology for MEMS Optimization. Microsystem Technologies, 21(1), 263–276.
Solaiman, A., et al. (2016). Application of General Multilevel Factorial Design with Formulation of Fast Disintegrating Tablets Containing Croscaremellose Sodium and Disintequick MCC-25. International Journal of Pharmaceutics, 501(1–2), 87–95.
Uniyal, S., et al. (2021). New Insights into the Biodegradation of Chlorpyrifos by a Novel Bacterial Consortium: Process Optimization using General Factorial Experimental Design. Ecotoxicology and Environmental Safety, 209, 111799.
Awadallah-F, A., & Naguib, H. F. (2017). Grafting of Tea Waste with Polyacrylic Acid and Its Potential Applications. Polymer Bulletin, 74(11), 4659-4679.
Atiqah, A., et al. (2019). Recycling and Sustainable Environmental Practices of Household Tea Waste. International Journal of Environmental Technology and Management, 22(4-5), 352–363.
Sukthavorn, K., et al. (2021). Fabrication of Green Composite Fibers from Ground Tea Leaves and Poly (Lactic Acid) as Eco-Friendly Textiles with Antibacterial Property. Journal of Material Cycles and Waste Management, 23(5), 1964-1973
Gao, P., & Ogata, Y. (2019). Biodegradability of PLA and Tea Waste Composites Based on “CHAMU” and the “Tea Waste Recycling System”. IOP Conference Series: Materials Science and Engineering, 563(2), 022034.
Duan, J., et al. (2016). Effects of Spent Tea Leaf Powder on the Properties and Functions of Cellulose Green Composite Films. Journal of Environmental Chemical Engineering, 4(1), 440-448.
Wu, C. (2018). Preparation, Characterization and Bioactivity of the Polyester and Tea Waste Green Composites. Polymer Bulletin, 75(11), 5197-5216.
Noori, A., et al. (2020). Development of Pressure-Responsive Polypropylene and Biochar-Based Materials. Micromachines, 11(4), 339.
de Cademartori, P. H. G., Silva, et al. (2015). Roughness and Color Evaluation of Wood Polymer Composites Filled by Household Waste of Mate-Tea. Maderas. Ciencia y tecnología, 17(3), 457–468.
Mattos, B. D., et al. (2014). Properties of Polypropylene Composites Filled with a Mixture of Household Waste of Mate-Tea and Wood Particles. Construction and Building Materials, 61, 60–68.
Lanjewar, S. R., et al. (2018). Preparation and Analysis of Polypropylene Composites with Maleated Tea Dust Particles. Science and Engineering of Composite Materials, 25(2), 373-381.
Rathod, Y., et al. (2017). Elaboration of Performance of Tea Dust–Polypropylene Composites. Journal of Applied Polymer Science, 134(17), 44750.
Bari, P., et al. (2015). Influence of the Coupling Agent and Graphene Oxide on the Thermal and Mechanical Behavior of Tea Dust–Polypropylene Composites. Journal of Applied Polymer Science, 133(4), 42927.
Dönmez Çavdar, A., et al. (2011). Tea Mill Waste Fibers Filled Thermoplastic Composites: The Effects of Plastic Type and Fiber Loading. Journal of Reinforced Plastics and Composites, 30(10), 833-844.
Xia, G., et al. (2015). Preparation and Properties of Biodegradable Spent Tea Leaf Powder/Poly (Propylene Carbonate) Composite Films. International Journal of Polymer Analysis and Characterization, 20(4), 377-387.
Bagheri, S., et al. (2022). Sound Absorption Performance of Tea Waste Reinforced Polypropylene and Nanoclay Biocomposites. Polymer Bulletin, 80, 5203–5218.
Prabhu, L., et al. (2020). Study of mechanical and Morphological Properties of Jute-Tea Leaf Fiber Reinforced Hybrid Composites: Effect of Glass Fiber Hybridization. Materials Today: Proceedings, 27(3), 2372-2375.
Hou LiJen, H. L., et al. (2009). Manufacture and Properties of Particleboards by Mixing Green Tea Leaves Waste with wood-Based Particles. Forest Products Industries, 28(1), 53-62.
Batiancela, M. A., et al. (2014). Particleboard from Waste Tea Leaves and wood Particles. Journal of Composite Materials, 48(8), 911-916.
Prabhu, L., et al. (2019). Mechanical, Chemical and acoustical Behavior of sisal–Tea Waste–Glass Fiber Reinforced Epoxy Based Hybrid Polymer Composites. Materials Today: Proceedings, 16(2), 653-660.
Yi, S., et al. (2019). Synergistic toughening Effects of grafting Modification and elastomer-Olefin Block Copolymer Addition On the fracture Resistance of wood Particle/ Polypropylene/ Elastomer Composites. Materials & Design, 181, 107918.
Teodorescu, G. M., et al., (2024). The Effect of Thermoplastic Elastomer and Fly Ash on the Properties of Polypropylene Composites with Long Glass Fibers. Polymers, 16(9), 1238.
Zheng, C., et al. (2018). AC performance, Physical and mechanical Properties of polypropylene/Polyolefin Elastomers Blends. In 2018 12th International Conference on the Properties and Applications of Dielectric Materials (p.910-913). 20 -24 May, 2018, Xi’an, China.
Stark, N. M., & Rowlands, R. E. (2003). Effects of Wood Fiber Characteristics on Mechanical Properties of Wood/Polypropylene Composites. Wood and Fiber Science. 35(2), 167-174.
Ashori, A., (2008). Wood – Plastic Composites as promising Green - Composites for automotive Industries. Bioresource Technology, 99(11), 4661–4667.
Klyosov, A. A. (2007). Wood-plastic composites. New Jersey: John Wiley & Sons.
Najafi, S. K., (2013). Use of recycled Plastics in wood Plastic Composites – A Review. Waste Management, 33(9), 1898–1905.
Spear, M. J., et al. (2015). Wood polymer composites. In Ansell, M. P. (Ed.). Wood Composites (p. 195-249). Cambridge: Woodhead Publishing.
Hugot, F., & Cazaurang, G. (2009). Mechanical Properties of an Extruded Wood Plastic Composite. Mécanique & Industries, 10(6), 519–524.
Xu, H., et al. (2023). Mechanical Properties Variation in Wood-Plastic Composites with a Mixed Wood Fiber Size. Materials, 16(17), 5801.