Impact of the nature and shape of cellulosic nanoparticles on the isothermal crystallization kinetics of poly(ε-caprolactone)
2011; Elsevier BV; Volume: 47; Issue: 12 Linguagem: Inglês
10.1016/j.eurpolymj.2011.09.014
ISSN1873-1945
AutoresGilberto Siqueira, Carole Fraschini, Julien Bras, Alain Dufresne, Robert E. Prud’homme, Marie‐Pierre Laborie,
Tópico(s)Natural Fiber Reinforced Composites
ResumoPolycaprolactone (PCL)/cellulose nanocomposites were prepared by mixing PCL with surface modified sisal nanowhiskers (CNW) and microfibrillated cellulose (MFC) extracted from sisal fibers. The influence of cellulosic nanoparticles on the crystallization behavior of PCL was investigated by differential scanning calorimetry. Isothermal crystallization data were modeled with Avrami's kinetics, Lauritzen–Hoffman secondary nucleation theory and equilibrium melting points were determined with the Hoffman–Weeks method. The cellulose nanoparticles, acting as nucleating agents, drastically accelerate the crystallization of PCL while depressing its equilibrium melting by 9–10 °C. The crystallization of MFC-nanocomposites is slightly faster than that of CNW-nanocomposites, in agreement with the slightly lower bulk activation energy for crystallization and nucleation parameter in the former. The results are discussed based on the differences of specific surface area and surface chemistry of nanoparticles, as well as the confinement phenomenon.
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