Preparation of Polypropylene/Bentonite Composites of Enhanced Thermal and Mechanical Properties using L-leucine and Stearic Acid as Coupling Agents


  • N. Mohammedi Department of Process Engineering, Ferhat Abbas Setif University 1, Algeria
  • F. Zoukrami Emerging Materials Research Unit, Ferhat Abbas Setif University 1, Algeria
  • N. Haddaoui Department of Process Engineering, Ferhat Abbas Setif University 1, Algeria


The compatibilization of raw bentonite (bent) with a polymer matrix of polypropylene (PP) can improve the performance of the material in terms of thermal and mechanical properties. In this study, two kinds of untreated bentonite, bentonite-Maghnia (bent-m) and bentonite-Mostaganem (bent-M), that differ in the proportion of Al2O3 and in the particle size distribution were coupled to typical maleic anhydride grafted polypropylene PP-MA. Stearic Acid (SA) and L-leucine Amino Acid (AA) were selected as new coupling modifiers at a 5/5 ratio of bentonite/coupling agent. All PP/bent composites were prepared by melt mixing at 190°C. Morphological observation revealed a good dispersion of bentonite into the PP matrix in the presence of AA, SA, and PP-MA. Mechanical properties showed an increase in stiffness as bent-m or bent-M were associated with AA. For instance, PP/bent-m/AA composite underwent an improvement of about 13% in Young’s modulus as compared to neat PP. On the other hand, the addition of SA into bent-m maintained stiffness and tensile strength at an acceptable level. An increase of around 40°C and 37% in the decomposition temperature and elongation at break was respectively observed for the PP/bent-m/SA composite. All coupled composites showed high degradation temperatures.


bentonite, surfactant, coupling agent, mechanical properties, layered composite


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T. G. Mofokeng, S. S. Ray, V. Ojijo, and R. Salehiyan, “Tuning the nano/micro-structure and properties of melt-processed ternary composites of polypropylene/ethylene vinyl acetate blend and nanoclay: The influence of kinetic and thermodynamic parameters,” Journal of Applied Polymer Science, vol. 135, no. 1, 2018, Art. no. 45585. DOI:

N. Zaman, S. Ahmed, M. Sanaullah, A. U. Rehman, A. R. Shar, and M. R. Luhur, “Fabrication and Characterization of Organoclay Reinforced Polyester Based Hybrid Nanocomposite Materials,” Engineering, Technology & Applied Science Research, vol. 8, no. 3, pp. 3038–3040, Jun. 2018. DOI:

B. A. A. Majeed and D. A. Sabar, “Preparations of Organoclay Using Cationic Surfactant and Characterization of PVC/ (Bentonite and Organoclay) Composite Prepared via Melt Blending Method,” Iraqi Journal of Chemical and Petroleum Engineering, vol. 18, no. 1, pp. 17–36, Mar. 2017.

R. S. Cardoso, V. O. Aguiar, and M. de F. V. Marques, “Masterbatches of polypropylene/clay obtained by in situ polymerization and melt-blended with commercial polypropylene,” Journal of Composite Materials, vol. 51, no. 25, pp. 3547–3556, Oct. 2017. DOI:

Y. Hernandez et al., “Improvement of toughness properties of polypropylene filled with nanobentonite using stearic acid as interface modifier,” Journal of Composite Materials, vol. 51, no. 3, pp. 373–380, Feb. 2017. DOI:

D. D. J. Rousseaux, M. Sclavons, P. Godard, and J. Marchand-Brynaert, “Tuning the functionalization chemistry of polypropylene for polypropylene/clay nanocomposites,” Reactive and Functional Polymers, vol. 72, no. 1, pp. 17–24, Jan. 2012. DOI:

S. K. Sharma and S. K. Nayak, “Surface modified clay/polypropylene (PP) nanocomposites: Effect on physico-mechanical, thermal and morphological properties,” Polymer Degradation and Stability, vol. 94, no. 1, pp. 132–138, Jan. 2009. DOI:

M. Alexandre and P. Dubois, “Polymer-layered silicate nanocomposites: preparation, properties and uses of a new class of materials,” Materials Science and Engineering: R: Reports, vol. 28, no. 1, pp. 1–63, Jun. 2000. DOI:

B. Uzbas and A. C. Aydin, “Microstructural Analysis of Silica Fume Concrete with Scanning Electron Microscopy and X-Ray Diffraction,” Engineering, Technology & Applied Science Research, vol. 10, no. 3, pp. 5845–5850, Jun. 2020. DOI:

G. Bulut, M. Chimeddorj, F. Esenli, and M. S. Çelik, “Production of desiccants from Turkish bentonites,” Applied Clay Science, vol. 46, no. 2, pp. 141–147, Oct. 2009. DOI:

S. Cara, G. Carcangiu, G. Padalino, M. Palomba, and M. Tamanini, “The bentonites in pelotherapy: chemical, mineralogical and technological properties of materials from Sardinia deposits (Italy),” Applied Clay Science, vol. 16, no. 1, pp. 117–124, Jan. 2000. DOI:

E. M. Araújo et al., “The influence of organo-bentonite clay on the processing and mechanical properties of nylon 6 and polystyrene composites,” Materials Science and Engineering: B, vol. 112, no. 2, pp. 175–178, Sep. 2004. DOI:

B. Abu-Jdayil, K. Al-Malah, and R. Sawalha, “Study on Bentonite-Unsaturated Polyester Composite Materials,” Journal of Reinforced Plastics and Composites, vol. 21, no. 17, pp. 1597–1607, Nov. 2002. DOI:

B. Abu-Jdayil and K. Al-Malah, “Jordanian Clay-Based Heat Insulator Composites: Mechanical Properties,” Journal of Reinforced Plastics and Composites, vol. 27, no. 14, pp. 1559–1568, Sep. 2008. DOI:

N. Hasegawa, M. Kawasumi, M. Kato, A. Usuki, and A. Okada, “Preparation and mechanical properties of polypropylene-clay hybrids using a maleic anhydride-modified polypropylene oligomer,” Journal of Applied Polymer Science, vol. 67, no. 1, pp. 87–92, 1998. DOI:<87::AID-APP10>3.0.CO;2-2

R. Doufnoune, F. Riahi, S. Bouchareb, and A. Ourari, “Silanization of natural Na+-maghnite algerian clay pre-intercalated with a cationic alkylphosphonium salt,” Journal of Adhesion Science and Technology, vol. 33, no. 6, pp. 616–634, Mar. 2019. DOI:

W. Mo, Q. He, X. Su, S. Ma, J. Feng, and Z. He, “Preparation and characterization of a granular bentonite composite adsorbent and its application for Pb2+ adsorption,” Applied Clay Science, vol. 159, pp. 68–73, Jun. 2018. DOI:

D. Garcı́a-López, O. Picazo, J. C. Merino, and J. M. Pastor, “Polypropylene–clay nanocomposites: effect of compatibilizing agents on clay dispersion,” European Polymer Journal, vol. 39, no. 5, pp. 945–950, May 2003. DOI:

H. Baniasadi, A. Ramazani S.A., and S. Javan Nikkhah, “Investigation of in situ prepared polypropylene/clay nanocomposites properties and comparing to melt blending method,” Materials & Design, vol. 31, no. 1, pp. 76–84, Jan. 2010. DOI:

H. Md. Akil, M. F. A. Rasyid, and J. Sharif, “Effect of Compatibilizer on Properties of Polypropylene Layered Silicate Nanocomposite,” Procedia Chemistry, vol. 4, pp. 65–72, Jan. 2012. DOI:

G. Lagaly and T. J. Pinnavia, “Clay mineral - Polymer nanocomposites,” Applied Clay Science, vol. 15, no. 1–2, 1999.

L. Minkova, Y. Peneva, E. Tashev, S. Filippi, M. Pracella, and P. Magagnini, “Thermal properties and microhardness of HDPE/clay nanocomposites compatibilized by different functionalized polyethylenes,” Polymer Testing, vol. 28, no. 5, pp. 528–533, Aug. 2009. DOI:

C. D. Angel et al., “Mechanical and rheological properties of polypropylene/bentonite composites with stearic acid as an interface modifier,” Journal of Applied Polymer Science, vol. 132, no. 30, 2015. DOI:

L. Gonzalez et al., “Mechanical and Thermal Properties of Polypropylene/Montmorillonite Nanocomposites Using Stearic Acid as Both an Interface and a Clay Surface Modifier,” Polymer Composites, vol. 35, no. 1, Jan. 2014. DOI:

Q. Han, R. Yang, J. Li, Y. Zhang, and C. Wang, “Synthesis of leucine micro/nanocrystals for pharmaceutical applications,” CrystEngComm, vol. 13, no. 20, pp. 6157–6162, Sep. 2011. DOI:

E. G. Pradas, M. V. Sánchez, F. C. Cruz, M. S. Viciana, and M. F. Pérez, “Adsorption of cadmium and zinc from aqueous solution on natural and activated bentonite,” Journal of Chemical Technology & Biotechnology, vol. 59, no. 3, pp. 289–295, 1994. DOI:

H. Khalaf, O. Bouras, and V. Perrichon, “Synthesis and characterization of Al-pillared and cationic surfactant modified Al-pillared Algerian bentonite,” Microporous Materials, vol. 8, no. 3, pp. 141–150, Feb. 1997. DOI:

O. Bouras, J.-C. Bollinger, M. Baudu, and H. Khalaf, “Adsorption of diuron and its degradation products from aqueous solution by surfactant-modified pillared clays,” Applied Clay Science, vol. 37, no. 3, pp. 240–250, Sep. 2007. DOI:

Y. Tang et al., “Preparation and thermal stability of polypropylene/montmorillonite nanocomposites,” Polymer Degradation and Stability, vol. 82, no. 1, pp. 127–131, Jan. 2003. DOI:

K.-N. Kim, H. Kimm, and J.-W. Lee, “Effect of interlayer structure, matrix viscosity and composition of a functionaiized polymer on the phase structure of polypropylene-montmorillonite nanocomposites,” Polymer Engineering & Science, vol. 41, no. 11, pp. 1963–1969, 2001. DOI:

D. Marchant and K. Jayaraman, “Strategies for Optimizing Polypropylene−Clay Nanocomposite Structure,” Industrial & Engineering Chemistry Research, vol. 41, no. 25, pp. 6402–6408, Dec. 2002. DOI:

W. Lertwimolnun and B. Vergnes, “Influence of compatibilizer and processing conditions on the dispersion of nanoclay in a polypropylene matrix,” Polymer, vol. 46, no. 10, pp. 3462–3471, Apr. 2005. DOI:

M. J. Solomon, A. S. Almusallam, K. F. Seefeldt, A. Somwangthanaroj, and P. Varadan, “Rheology of Polypropylene/Clay Hybrid Materials,” Macromolecules, vol. 34, no. 6, pp. 1864–1872, Mar. 2001. DOI:

B. Wunderlich, “Athas table of thermal properties of linear macromolecules,” in Thermal Analysis, London, UK: Academic Press Limited, 1990, pp. 417–431. DOI:

N. Othman, H. Ismail, and M. Mariatti, “Effect of compatibilisers on mechanical and thermal properties of bentonite filled polypropylene composites,” Polymer Degradation and Stability, vol. 91, no. 8, pp. 1761–1774, Aug. 2006. DOI:

S. Sánchez-Valdes et al., “Effect of different amine modified clays on the compatibility and clay dispersion of polypropylene nanocomposites,” e-Polymers, vol. 9, no. 1, Dec. 2009. DOI:

B. Kim, S.-H. Lee, D. Lee, B. Ha, J. Park, and K. Char, “Crystallization Kinetics of Maleated Polypropylene/Clay Hybrids,” Industrial & Engineering Chemistry Research, vol. 43, no. 19, pp. 6082–6089, Sep. 2004. DOI:

P. Liborio, V. A. Oliveira, and M. de F. V. Marques, “New chemical treatment of bentonite for the preparation of polypropylene nanocomposites by melt intercalation,” Applied Clay Science, vol. 111, pp. 44–49, Jul. 2015. DOI:

F.-C. Chiu, H.-Z. Yen, and C.-E. Lee, “Characterization of PP/HDPE blend-based nanocomposites using different maleated polyolefins as compatibilizers,” Polymer Testing, vol. 29, no. 3, pp. 397–406, May 2010. DOI:

E. M. Essassi, M. Yahya, S. El Kazzouli, and M. Bousmina, “Synthesis and characterization of new organophilic clay. Preparation of polystyrene/clay nanocomposite,” Scientific Study & Research: Chemistry & Chemical Engineering, Biotechnology, Food Industry, vol. 19, no. 2, pp. 193–202, Jul. 2018.

S. Yu. Khashirova, Yu. I. Musaev, A. K. Mikitaev, Yu. A. Malkanduev, and M. Kh. Ligidov, “Hybrid nanocomposites based on guanidine methacrylate monomer and polymer and layered aluminosilicates: Synthesis, structure, and properties,” Polymer Science Series B, vol. 51, no. 9, Nov. 2009, Art. no. 377. DOI:

H. Olphen and J. J. Fripiat, Data handbook for clay materials and other non-metallic minerals. Oxford, UK: Pergamon Press, 1979.

M. El Bouraie and A. A. Masoud, “Adsorption of phosphate ions from aqueous solution by modified bentonite with magnesium hydroxide Mg(OH)2,” Applied Clay Science, vol. 140, pp. 157–164, May 2017. DOI:

S. Kumar, “Spectroscopic studies of valine and leucine molecules a comparative study,” vol. 2011, no. 39, pp. 4996–4999, 2011.

B. H. Stuart, Polymer Analysis, 1st ed. Chichester, NY, USA: Wiley, 2002.

V. S. Kumar, “Thermal Properties of Polypropylene/Montmorillonite Nanocomposites,” Indian Journal of Science and Technology, vol. 7, no. Suppl. 7, Jan. 2015. DOI:

E. Kontou, M. Niaounakis, and P. Georgiopoulos, “Comparative study of PLA nanocomposites reinforced with clay and silica nanofillers and their mixtures,” Journal of Applied Polymer Science, vol. 122, no. 3, pp. 1519–1529, 2011. DOI:

S. Chaoui, D. Smail, A. Hellati, and D. Benachour, “Effect of Starch Nanocrystals on the Properties of Low Density Polyethylene/Thermoplastic Starch Blends,” Engineering, Technology & Applied Science Research, vol. 10, no. 4, pp. 5875–5881, Aug. 2020. DOI:

B. Akbari and R. Bagheri, “Influence of PP-g-MA on morphology, mechanical properties and deformation mechanism of copolypropylene/clay nanocomposite,” Journal of Applied Polymer Science, vol. 114, no. 6, pp. 3751–3759, 2009. DOI:

J. Son, D. J. Gardner, S. O’Neill, and C. Metaxas, “Understanding the viscoelastic properties of extruded polypropylene wood plastic composites,” Journal of Applied Polymer Science, vol. 89, no. 6, pp. 1638–1644, 2003. DOI:

J. M. Quiroz-Castillo et al., “Preparation and Characterization of Films Extruded of Polyethylene/Chitosan Modified with Poly(lactic acid),” Materials, vol. 8, no. 1, pp. 137–148, Jan. 2015. DOI:

H. Qin et al., “Thermal stability and flammability of polypropylene/montmorillonite composites,” Polymer Degradation and Stability, vol. 85, no. 2, pp. 807–813, Aug. 2004. DOI:

J. Morawiec, A. Pawlak, M. Slouf, A. Galeski, E. Piorkowska, and N. Krasnikowa, “Preparation and properties of compatibilized LDPE/organo-modified montmorillonite nanocomposites,” European Polymer Journal, vol. 41, no. 5, pp. 1115–1122, May 2005. DOI:

C. Ding, D. Jia, H. He, B. Guo, and H. Hong, “How organo-montmorillonite truly affects the structure and properties of polypropylene,” Polymer Testing, vol. 24, no. 1, pp. 94–100, Feb. 2005. DOI:

N. el H. Belkham, D. Benachour, and A. Mehamha, “Elaboration and Physico-Chemical Characterization of the Gibbsite Li(OH)3 Hybrid Material,” Engineering, Technology & Applied Science Research, vol. 11, no. 1, pp. 6740–6744, Feb. 2021. DOI:


How to Cite

N. Mohammedi, F. Zoukrami, and N. Haddaoui, “Preparation of Polypropylene/Bentonite Composites of Enhanced Thermal and Mechanical Properties using L-leucine and Stearic Acid as Coupling Agents”, Eng. Technol. Appl. Sci. Res., vol. 11, no. 3, pp. 7207–7216, Jun. 2021.


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