Improvement of Mechanical and Viscoelastic Properties of Polypropylene with Wood and Wollastonite Fillers

Abstract

In recent years, polypropylene has become one of the most popular thermoplastic polymers due to its excellent properties, chemical resistance, affordability, and easy processing. When reinforced with glass fibers, wood fibers, or mineral fillers, polypropylene composites exhibit enhanced mechanical strength, stiffness, and durability. This makes them suitable for applications where high performance and specific mechanical properties are required, such as in automotive interior parts, building materials, and consumer goods. This research analyzes the effects of wood fibers as an organic filler and wollastonite mineral as an inorganic filler on the mechanical and viscoelastic properties of polypropylene. Various weight ratios of these fillers were added into polypropylene to produce hybrid biocomposites using a laboratory-type high-speed thermokinetic mixer and a heated-cooled hydraulic press. The mechanical properties were determined by tensile and three-point bending tests, and viscoelastic properties were analyzed using dynamic mechanical analysis. The test results indicated that the polypropylene composite sample containing 7% by weight of silane-treated wollastonite and 3% by weight of wood fibers showed the best results among all samples. The storage and loss moduli of the sample are approximately 25% and 22% higher than those of the polypropylene, respectively. Overall, hybrid biocomposites filled with silane-treated wollastonite exhibited enhanced mechanical and viscoelastic properties compared to those filled with untreated wollastonite, as supported by the experimental data.

Keywords

• Organic and inorganic fillers
• Hybrid composites
• Mechanical properties
• Polypropylene
• Silane-treated wollastonite
• Viscoelastic properties

Thanks

The authors would like to thank KAOLIN Industrial Minerals, Türkiye, for the wollastonite supply.

References

1. [1]. Ashori A. Wood–plastic composites as promising green-composites for automotive industries! Bioresour Technol. 2008; 99(11):4661–7.
2. [2]. Faruk O, Bledzki AK, Fink HP, Sain M. Biocomposites reinforced with natural fibers: 2000–2010. Top Issue Polym Biomater. 2012 Nov 1; 37(11):1552–96.
3. [3]. Koronis G, Silva A, Fontul M. Green composites: A review of adequate materials for automotive applications. Compos Part B Eng. 2013; 44(1):120–7.
4. [4]. Savran M, Öncül M, Yılmaz M, Aydın L, Sever K. Modeling and optimization of dynamic-mechanical properties of hybrid polymer composites by multiple nonlinear neuro-regression method. Sigma J Eng Nat Sci. 2023; 41(6):1243–54.
5. [5]. Mohan Sharma A. Mechanical Behaviour, Water Absorption and Morphology of Wheat Straw, Talc, Mica and Wollastonite filled Polypropylene Composites [Internet] [Master’s Thesis]. University of Waterloo; 2012 [cited 2024 Sep 10]. Available from: https://uwspace.uwaterloo.ca/handle/10012/6772
6. [6]. Chan JX, Wong JF, Hassan A, Mohamad Z, Othman N. Mechanical properties of wollastonite reinforced thermoplastic composites: A review. Polym Compos. 2020 Feb; 41(2):395–429.
7. [7]. Karagöz İ, Büyükkaya K, Demirer H, Mudu M, Kartal İ. Mechanical and thermal characterization of elastomer modified polypropylene hybrid composites reinforced with hazelnut shell and wollastonite fillers. J Appl Polym Sci. 2024 Aug 10; 141(30):e55710.
8. [8]. Atagür M, Kaya N, Uysalman T, Durmuşkahya C, Sarikanat M, Sever K, et al. A detailed characterization of sandalwood-filled high-density polyethylene composites. J Thermoplast Compos Mater. 2020 Jul 31; 089270572093915.

9. [9]. Savran M, Yılmaz M, Öncül M, Sever K. Manufacturing and Modeling of Polypropylene-based Hybrid Composites by Using Multiple-Nonlinear Regression Analysis. Sci Res Commun. 2022 Jan 30; 2(1):1–15.
10. [10]. Sever K, Yılmaz M. Evaluation of Mechanical and Thermal Properties of Artichoke Filled Polypropylene Composites: Influence of Wollastonite Hybridization. Emerg Mater Res. 2020 Jun 1;9(2):1–6.
11. [11]. Geissdoerfer M, Savaget P, Bocken NM, Hultink EJ. The Circular Economy–A new sustainability paradigm? J Clean Prod. 2017; 143:757–68.
12. [12]. Mohanty AK, Misra M, Drzal LT. Natural fibers, biopolymers, and biocomposites. CRC press; 2005.
13. [13]. Chen M, Wan C, Shou W, Zhang Y, Zhang Y, Zhang J. Effects of interfacial adhesion on properties of polypropylene/Wollastonite composites. J Appl Polym Sci. 2008 Feb 5; 107(3):1718–23.
14. [14]. Wong JF, Chan JX, Hassan AB, Mohamad ZB, Othman NB. Thermal and flammability properties of wollastonite-filled thermoplastic composites: a review. J Mater Sci. 2021 May; 56(15):8911–50.
15. [15]. Andrady AL. Science and technology of polymer nanofibers [Internet]. John Wiley & Sons; 2008 [cited 2024 Sep 10]. Available from: https://books.google.com/books?hl=en&lr=&id=KOdoYIuFHzAC&oi=fnd&pg=PR7&dq=Science+and+Technology+of+Polymer+Nanofibers&ots=ue1XtfEz3l&sig=HkcLBWLddnWjU5ezGCQL4INGYYY
16. [16]. Joseph P, Joseph K, Thomas S, Pillai C, Prasad V, Groeninckx G, et al. The thermal and crystallisation studies of short sisal fibre reinforced polypropylene composites. Compos Part Appl Sci Manuf. 2003; 34(3):253–66.
17. [17]. Luyt AS, Dramićanin MD, Antić Ž, Djoković V. Morphology, mechanical and thermal properties of composites of polypropylene and nanostructured wollastonite filler. Polym Test. 2009; 28(3):348–56.
18. [18]. Fu SY, Lauke B, Mäder E, Yue CY, Hu X. Tensile properties of short-glass-fiber-and short-carbon-fiber-reinforced polypropylene composites. Compos Part Appl Sci Manuf. 2000; 31(10):1117–25.
19. [19]. Lee SY, Kang IA, Doh GH, Yoon HG, Park BD, Qinglin Wu. Thermal and Mechanical Properties of Wood Flour/Talc-filled Polylactic Acid Composites: Effect of Filler Content and Coupling Treatment. J Thermoplast Compos Mater. 2008 May; 21(3):209–23.
20. [20]. Malkapuram R, Kumar V, Yuvraj Singh Negi. Recent Development in Natural Fiber Reinforced Polypropylene Composites. J Reinf Plast Compos. 2009 May; 28(10):1169–89.