Modification of Turkish Pumice Mineral and Its Use as Additive for Poly (Lactic Acid) Based Bio-Composite Materials

In this study, Turkish pumice (P) mineral was treated with silane in order to increase the compatibility for poly(lactic acid) (PLA) which is a fully biodegradable polymer widely used in packaging and outdoor applications. Neat and treated P powders were compounded with PLA at the concentrations of 5, 10, 15 and 20 wt% by melt mixing process. Surface characteristics of P samples were examined using infrared spectroscopy. Mechanical, water uptake, melt-flow and morphological properties of prepared composites were investigated by tensile and impact tests, water absorption test, melt flow rate test (MFR) and scanning electron microscopy (SEM) technique, respectively. Mechanical test results revealed that the highest increase in tensile strength and modulus values was obtained for 15 wt% of silanized P containing composite. Silane treated P additions to PLA caused increase in impact energy compared to untreated P sample. Impact energies of composites increased with concentration. Silanized P filled composite gave slightly higher MFR values with respect to pristine P. Water absorption of composites were found as higher than that of unfilled PLA. Composites containing silanized P exhibited lower water uptake values compared to untreated P samples because of the hydrophobic character of silicon containing surfaces. SEM micro-images of composites displayed that more homogeneous dispersion in PLA matrix was taken place for silane treated P particles than that of neat P stem from the increase of adhesion between P and PLA surfaces after silanization process.

Anahtar Kelimeler:

Pumice, Poly (lactic acid), Bio-composites, Extrusion, Polymer composites

Türk Pomza Mineralinin Modifikasyonu ve Poli (Laktik Asit) Bazlı Biyo-Kompozit Malzemelerinde Eklenti Olarak Kullanımı

Bu çalışmada, Türk pomza (P) minerali, ambalaj ve dış ortam uygulamalarında sıkça kullanılan tamamen biyobozunur bir polimer olan poli (laktik asit) (PLA) ile uyumunu artırmak amacıyla silan ile muamele edilmiştir. Muamele edilen ve edilmeyen P tozları PLA ile eriyik karıştırma yöntemi ile 5, 10, 15 ve 20 ağırlıkça % konsantrasyonlarında eklenmiştir. P numunelerinin yüzey özellikleri infrared spektrofotometre kullanılarak incelenmiştir. Hazırlanan kompozitlerin mekanik, su alma, erime-akış ve morfolojik özellikleri sırasıyla çekme ve darbe testleri, su emme testi, erime akış hızı testi (MFR) ve taramalı elektron mikroskopi (SEM) teknikleri ile araştırılmıştır. Mekanik test sonuçlarına göre, çekme dayanım ve modülde en yüksek artışa %15 silanlanmış P içeren kompozitte rastlanmıştır. PLA içine silane ile muamele edilmiş P eklenmesi, edilmemiş P numunesi ile kıyasla darbe dayanımında artışa neden olmuştur. Kompozitlerin darbe dayanımları konsantrasyon ile artmıştır. Silanlanmış P eklenmiş kompozit P içerene göre bir miktar yüksek MFR değeri vermiştir. Kompozitlerin su emmeleri eklentisiz PLA’dan fazla olarak bulunmuştur. Silikon içeren yüzeylerin su sevmeyen özelliğinden dolayı silanlanmış P içeren kompozitler, modifiyesiz P ile kıyaslandığında daha düşük su emme değerleri sergilemiştir. Kompozitlerin SEM mikro-resimleri göstermektedir ki; silanlama işleminden sonar P ile PLA arasında yapışma arttığı için silan ile muamele edilmiş P parçacıklarında edilmeyenlere göre daha homojen dağılım gerçekleşmiştir.

Keywords:

pomza, Poli (laktik asit), Biyo-kompozitler, Ekstrüzyon, Polimer kompozitler,

PDF

___

[1] Mohanty, A.K., Misra, M., Drzal, L.T. (2002). Sustainable bio-composites from renewable resources opportunities and challenges in the green materials world. J Polym Environ, 10(1-2), 19-26.
[2] Tayfun, U. (2015). Influence of surface treatment of fillers on the mechanical properties of thermoplastic polyurethane composites. PhD, Middle East Technical University, Ankara, Turkey.
[3] Bismarck, A., Baltazar, A., Jimenez, Y., Sarikakis, K. (2006). Green composites as panacea? Socio-economic aspects of green materials. Environ Dev Sustain, 8(3), 445-463.
[4] Weber, C. J., Haugaard, V., Festersen, R., Bertelsen, G. (2002). Production and applications of biobased packaging materials for the food industry. Food Addit Contam, 19, 172-177.
[5] Bajpai, P. K., Singh, I., Madaan, J. (2012). Development and characterization of PLA-based green composites: A review. J Thermoplast Compos Mater, 27, 52-81.
[6] Rasal, R. M., Janorkar, A. V., Hirt, D. E. (2010). Poly (lactic acid) modifications. Prog Polym Sci, 35, 338-356.
[7] Murariu, M., Dubois, P. (2016). PLA composites: From production to properties. Adv Drug Deliv Rev, 107, 17-46.
[8] Ren, J. (2011). Biodegradable poly (lactic acid): Synthesis, modification, processing and applications. Springer: Verlag.
[9] Xanthos, M. (2005). Functional fillers for plastics. Weinheim, Wiley VCH.
[10] Theberge, J. E. (1982). Mineral reinforced thermoplastic composites. J Elastom Plast, 14(2), 100-108.
[11] Oktem, G. A., Tincer, T. (1994). Preparation and characterization of perlite-filled high- density polyethylenes: 1. Mechanical Properties. J Appl Polym Sci, 54, 1103-1114.
[12] Kanbur, Y., Tayfun, U. (2017). Mechanical, physical and morphological properties of polypropylene/huntite composites. Sakarya Univ J Sci, 21(5), 1045-1050.
[13] Metin, D., Tihminhoglu, F., Balkose, D., Ulku, S. (2004). The effect of interfacial interactions on the mechanical properties of polypropylene/natural zeolite composites. Compos Part A Appl Sci Manuf, 35(1), 23-32.
[14] Rothon, R. N. (2003). Particulate-filled polymer composites, 2nd Edition, Rapra Technology Limited, UK.
[15] Kul, A. R., Benek, V., Selcuk A., Onursal, N. (2017). Using natural stone pumice in van region on adsorption of some textile dyes. JOTCSA, 4(2), 525-536.
[16] Bolen, W. P. (2008). Pumice and pumicite. Minerals Yearbook, U.S. Geological Survey, Virginia, USA.
[17] Elmastas, N. (2012) Türkiye Ekonomisi için önemi giderek artan bir maden: Pomza (sünger taşı). J Inter Soc Res, 5(23), 197-206.
[18] Yazicioglu, S., Arici, E., Gonen, T. (2003). Pomza taşının kullanım alanları ve ekonomiye etkisi. F.Ü. DAUM Dergisi, 118-123.
[19] Han, B., Sun, Z., Chen, Y., Tian, F., Wang, X., Lei, Q. (2009). Space charge distribution in low-density polyethylene (LDPE)/Pumice composite. Proceedings of the 9th International Conference on Properties and Applications of Dielectric Materials, Harbin, China, 19-23.
[20] Kanbur, Y., Tayfun, U. (2018). Mechanical, physical and morphological properties of acidic and basic pumice containing polypropylene composites. Sakarya Univ J Sci, 22(2), 333-339.
[21] Jayakrishnan, P., Ramesan, M. T. (2016). Synthesis, characterization and properties of poly (vinyl alcohol)/chemically modified and unmodified pumice composites. J Chem Pharma Sci, 1, 97-104.
[22] Yavuz, M., Gode, F., Pehlivan, E., Ozmert, S., Sharma, Y. C. (2008). An economic removal of Cu2+ and Cr3+ on the new adsorbents: Pumice and polyacrylonitrile/pumice composite. Chem Eng J, 137(3), 453-461.
[23] Ramesan, M.T., George, A., Jayakrishnan, P., Kalaprasad, G. (2016). Role of pumice particles in the thermal, electrical and mechanical properties of poly(vinyl alcohol)/poly(vinyl pyrrolidone) composites. J Therm Anal Calorim, 126(2), 511–519.
[24] Gok, A., Gode F., Turkaslan, B. E. (2006). Synthesis and characterization of polyaniline/pumice (PAn/Pmc) composite. Mater Sci Eng B, 133(1-3), 20–25.
[25] Sahin, A.E., Yildiran, Y., Avcu, E., Fidan, S., Sinmazcelik, T. (2013). Mechanical and thermal properties of pumice powder filled PPS composites. Proceedings of the 3rd International Congress, Antalya, Turkey, 24-28.
[26] Akkaya, R. (2013). Uranium and thorium adsorption from aqueous solution using a novel polyhydroxyethylmethacrylate-pumice composite. J Environ Radioact, 120, 58-63.
[27] Silverstein, R., Webster, F. (2006). Spectrometric identification of organic compounds. Wiley, New York.
[28] Dogan, S. D., Tayfun, U., Dogan, M. (2016). New route for modifying cellulosic fibers with fatty acids and its application to polyethylene/jute fiber composites. J Compos Mater, 50(18), 2475-2485.
[29] Yang, R., Liu, Y., Wang, K., Yu, J. (2003). Characterization of surface interaction of inorganic fillers with silane coupling agents. J Anal Appl Pyrol, 70(2), 413-425.
[30] Kilinc, K., Kanbur, Y., Tayfun, U. (2019). Mechanical, thermo-mechanical and water uptake performance of wood flour filled polyurethane elastomer eco-composites: influence of surface treatment of wood flour. Holzforschung, 73(4), 401-408.
[31] Shokoohi, S., Arefazar, A., Khosrokhavar, R. (2008). Silane coupling agents in polymer-based reinforced composites: A review. J Reinf Plast Compos, 27(5), 473–485.
[32] Ge, C., Ding, P., Shi, L., Fu, J. (2009). Isothermal crystallization kinetics and melting behavior of poly(ethylene terephthalate)/barite nanocomposites. J Polym Sci B Polym Phys, 47, 655-668.
[33] Tayfun, U., Dogan, M., Bayramli, E. (2017). Polyurethane elastomer as a matrix material for short carbon fiber reinforced thermoplastics. Anadolu Univ J Sci Technol A Appl Sci Eng, 18(3), 682-694.
[34] Tian, H. Y., Tagaya, H. (2007). Preparation, characterization and mechanical properties of the polylactide/perlite and the polylactide/montmorillonite composites. J Mater Sci, 42, 3244-3250.
[35] Arbelaiz, A., Fernández, B., Ramos, J. A., Retegi, A., Llano-Ponte, R., Mondragon, I. (2005). Mechanical properties of short flax fibre bundle/polypropylene composites: Influence of matrix/fibre modification, fibre content, water uptake and recycling. Compos Sci Technol, 65(10), 1582-1592.
[36] Tayfun, U., Dogan, M., Bayramli, E. (2016). Influence of surface modifications of flax fiber on mechanical and flow properties of TPU based eco-composites. J Nat Fibers, 13(3), 309-320.