بررسی تأثیر نانولوله‌های کربنی بر سینتیک بلورینگی پلی‌اتیلن با چگالی بالا (HDPE)

نوع مقاله : علمی و پژوهشی

نویسندگان

دانشگاه فردوسی مشهد

چکیده

در این پژوهش نمونه­های پلی­اتیلن و نانوکامپوزیت پلی­اتیلن/نانولوله­ی کربنی با استفاده از دستگاه مینی­اکستروژن تهیه شدند. تغییرات خواص حرارتی و سینتیک بلورینگی غیرهمدمای پلی­اتیلن در حضور نانولوله­های کربنی با استفاده از آنالیز حرارتی روبشی تفاضلی در سرعت­های متفاوت سرمایش مورد بررسی قرار گرفتند. نتایج نشان می­دهند که دمای انجماد و آنتالپی فرآیند در حضور نانولوله­ها افزایش می­یابد. نانولوله­ها هم­چنین به عنوان نقاط جوانه­زنی رفتار می­کنند. علاوه بر این، درصد بلورینگی محاسبه شده در نمونه­های نانوکامپوزیتی نسبت به نمونه­ی خام افزایش یافته­است. هم­چنین، تغییر شاخص اورامی (n)، از مقدار 3 به 2 در نمونه­های کامپوزیتی دیده می­شود. درنهایت با به­کارگیری مدل­های کیسینگر و OFW انرژی فعال­سازی مورد نیاز فرآیند بلورینگی محاسبه شد.

کلیدواژه‌ها


عنوان مقاله [English]

Effect of Carbon Nanotubes on Thermal Properties and Crystallization Kinetics of High Density Polyethylene

نویسندگان [English]

  • samanrh sahebian
  • sare moazen
Ferdowsi university of Mshhad
چکیده [English]

In this study, HDPE and its nanocomposites with 1, 2.5 and 5 weight percent of carbon nanotube were prepared using mini-extrusion machine. Thermal properties and crystallization kinetics of samples were studied by differential scanning calorimetry methods at different cooling rates. Results shows that solidification and enthalpy increases in presence of carbon nanotubes. Carbon nanotubes acts as nucleation sites. Besides, relative crystallinity in nanocomposites is higher than pure polyethylene. Furthermore, Avrami index (n) decreases from 3 to 2 in nanocomposites. Finally, the activation energy for the crystallization process was calculated using Kissinger and OFW methods.

کلیدواژه‌ها [English]

  • HDPE
  • Carbon Nanotube
  • Crystallization kinetics
  • Thermal properties
1. Rusu M., Sofian N., Rusu D., "Mechanical and thermal properties of zinc powder filled high density polyethylene composites", Polymer Testing, Vol. 20, pp. 409-417, (2001)
2. Murty M., Grulke E., Bhattacharyya D., "Influence of metallic additives on thermal degradation and liquefaction of high density polyethylene (HDPE)", Polymer degradation and stability, Vol. 61, pp. 421-43, (1998).
3. Jin Y.-H., et. al., "Polyethylene/clay nanocomposite by in-situ exfoliation of montmorillonite during Ziegler-Natta polymerization of ethylene", Macromolecular rapid communications, Vol. 23, pp. 135-140, (2002).
4. Liu T., et. al., "Morphology and mechanical properties of multiwalled carbon nanotubes reinforced nylon-6 composites", Macromolecules,. Vol. 37, pp. 7214-7222, (2004).
5. Sanchez S., et. al., "Carbon nanotube/polysulfone soft composites: preparation, characterization and application for electrochemical sensing of biomarkers", Physical Chemistry Chemical Physics, Vol. 11, pp. 7721-7728, (2009).
6. Saito R., Dresselhaus G., Dresselhaus M.S., "Physical properties of carbon nanotubes", Vol. 35, World Scientific, (1998).
7. Moniruzzaman M., Winey K.I., "Polymer nanocomposites containing carbon nanotubes", Macromolecules, Vol. 39, pp. 5194-5205, (2006).
8. Ajayan P., "Nanotubes from carbon", Chemical reviews, Vol. 99, pp. 1787-1800, (1999).
9. Trujillo M., et. al., "Thermal and morphological characterization of nanocomposites prepared by in-situ polymerization of high-density polyethylene on carbon nanotubes", Macromolecules, Vol. 40, pp. 6268-6276, (2007).
10. Haggenmueller R., Fischer J.E., Winey K.I., "Single wall carbon nanotube/polyethylene nanocomposites: nucleating and templating polyethylene crystallites", Macromolecules, Vol. 39, pp. 2964-2971, (2006).
11. Minus M.L., Chae H.G., Kumar S., "Polyethylene crystallization nucleated by carbon nanotubes under shear", ACS applied materials & interfaces, Vol. 4, pp. 326-330, (2011).
12. Kim J., et. al., "Nonisothermal crystallization behaviors of nanocomposites prepared by in situ polymerization of high-density polyethylene on multiwalled carbon nanotubes", Macromolecules, Vol. 43, pp. 10545-10553, (2010).
13. Kumar S., et. al., "Fibers from polypropylene/nano carbon fiber composites", Polymer, Vol. 43, pp. 1701-1703, (2002).
14. Phang I.Y., et. al., "Crystallization and melting behavior of multi‐walled carbon nanotube‐reinforced nylon‐6 composite", Polymer International, Vol. 55, pp. 71-79, (2006).
15. Tzavalas S., et. al., "Effect of carboxy-functionalized multiwall nanotubes (MWNT-COOH) on the crystallization and chain conformations of poly (ethylene terephthalate) PET in PET-MWNT nanocomposites", Macromolecules, Vol. 39, pp. 9150-9156, (2006).
16. Gao Y., et. al., "Functionalized multi-walled carbon nanotubes improve nonisothermal crystallization of poly (ethylene terephthalate)", Polymer Testing, Vol. 27, pp. 179-188, (2008).
17. Ryan K., et. al., "Multiwalled carbon nanotube nucleated crystallization and reinforcement in poly (vinyl alcohol) composites", Synthetic Metals, Vol. 156, pp. 332-335, (2006).
18. Coleman J.N., et. al., "High performance nanotube-reinforced plastics: understanding the mechanism of strength increase", Advanced Functional Materials, Vol. 14, pp. 791-798, (2004).
19. Cadek M., et. al., "Morphological and mechanical properties of carbon-nanotube-reinforced semicrystalline and amorphous polymer composites", Applied physics letters, Vol. 81, pp. 5123-5125, (2002).
20. Kodjie S.L., et. al., "Morphology and crystallization behavior of HDPE/CNT nanocomposite Part B: Physics ", Journal of Macromolecular Science, Vol. 45, pp. 231-245, (2006).
21. Grady B.P., et. al., "Nucleation of polypropylene crystallization by single-walled carbon nanotubes", The Journal of Physical Chemistry B, Vol. 106, pp. 5852-5858, (2002).
22. Jin J., Song M., Pan F., "A DSC study of effect of carbon nanotubes on crystallisation behaviour of poly (ethylene oxide)", Thermochimica acta, Vol. 456, pp. 25-31, (2007).
23. Kim J.Y., Park H.S., Kim S.H., "Unique nucleation of multi-walled carbon nanotube and poly (ethylene 2, 6-naphthalate) nanocomposites during non-isothermal crystallization", Polymer, Vol. 47, No. 4, pp. 1379-1389, (2006).
CAPTCHA Image