| 학회 | 한국고분자학회 |
| 학술대회 | 2005년 봄 (04/14 ~ 04/15, 전경련회관) |
| 권호 | 30권 1호, p.583 |
| 발표분야 | 복합재료 |
| 제목 | Crystallization and Melting Behavior of PEN/silica Hybrid Nanocomposites |
| 초록 | Recently, polymer nanocomposites consisting of organic polymers and inorganic nanoparticles have attracted considerable attention because they significantly improves the mechanical, thermal, electrical, gas barrier properties, and the dimensional stability of the polymers with even small quantity of inorganic the nanocparticles, resulting in their potential applications as advanced materials for the aerospace, automotive, electric, and electronic industries.1-4 Currently, four processing techniques have been used commonly for incorporating inorganic nanoparticles into the polymer matrix to facilitate the dispersion of inorganic nanoparticles: direct mixing, in situ polymerization, solution method, and melt compounding.4-7 Among these methods, the melt compounding is more simple and effective process from a economic point of view rather than other processing techniques. In this research, the organic-inorganic hybrid nanocomposites consisting of poly(ethylene 2,6-naphthalate) (PEN) and silica nanoparticles were prepared by a melt blending process. The crystallization and melting behaviors of the PEN/silica hybrid nanocomposites was investigated with the isothermal crystallization analysis. Thermal stability of the PEN/silica hybrid nanocomposites was improved by adding silica nanoparticles. The increase in the crystallization temperature of the PEN/silica hybrid nanocomposites with increasing silica content, together with the fact that the PEN/silica hybird nanocomposites have lower degree of supercooling (△T = Tm - Tc) for the crystallization with increasing silica content, suggests that silica nanoparticles effectively acts as a nucleating agent in the PEN matrix. The decrease in the half time of the crystallization suggests that the incorporation of silica nanoparticles enhances the crystallization of the PEN matrix through heterogeneous nucleation, resulting in the higher crystallization rate. The values of activation energy (△Ea) for isothermal crystallization of PEN and PEN/silica 0.9 hybrid nanocomposites were 71.18 and 55.87 kJ/mol, respectively. The incorporation of silica nanoparticles into the PEN matrix induced more heterogeneous nucleation, causing a lower △Ea value. The PEN and PEN/silica hybrid nanocomposties exhibited double melting peaks in the DSC heating traces. As the crystallization temperature increased, the lower melting peaks gradually shifted higher temperature region, and eventually merged into only single peak at the crystallization temperature of 240 oC. The double melting behavior observed in the PEN/silica nanocomposites may be attributed to the different lamellae thickness distribution as a consequence of the melting-recrystallization process during the DSC scans. References 1. T. Lan, P. D. Kaviratna, and T. J. Pinnavaia, Chem. Mater., 6, 573 (1994). 2. Y. I. Tien and K. H. Wei, Macromolecules, 34, 9045 (2001) 3. S. H. Kim, S. H. Ahn, and T. Hirai, Polymer, 44, 5625 (2003) 4. B. M. Novak, Adv. Mater., 5, 283 (1993). 5. J. Z. Alexander, B. Morgan, J. Lamelas, and C. A. Wilkie, Chem. Mater., 13, 3774 (2001) 6. F. H. Gojny, J. Nastalczyk, Z. Roslaniec, and K. Schulte, Chem. Phys. Lett., 370, 820 (2003). 7. T. J. Pinnavaia and G. W. Beall, Polymer-Clay Nanocomposites, Wiley, New York, 2000. |
| 저자 | 김준영, 김성훈 |
| 소속 | 한양대 |
| 키워드 | Crystallization; Melting; Nanocomposites; PEN; Silica nanoparticle |
