کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
674506 1459563 2011 9 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Nonisothermal melt-crystallization kinetics for in situ prepared poly(ethylene terephthalate)/monmorilonite (PET/OMMT)
موضوعات مرتبط
مهندسی و علوم پایه مهندسی شیمی جریان سیال و فرایندهای انتقال
پیش نمایش صفحه اول مقاله
Nonisothermal melt-crystallization kinetics for in situ prepared poly(ethylene terephthalate)/monmorilonite (PET/OMMT)
چکیده انگلیسی

Poly(ethylene terephthalate) (PET) montmorillonite nanocomposites were prepared by in situ polymerization containing 0.5, 1, 2 and 5 wt% of organically modified montmorillonite (OMMT). In order to prepare exfoliated nanocomposites a new thermally stable modifier for montmorillonite nanoparticles like chlorohexadecane triphenylphosphine (CHDTPP) was synthesized. The preparation of nanocomposites was carried out using the two-stage melt polycondensation method. As verified by TEM micrographs, the dispersion of OMMT nanoparticles into the PET matrix was homogeneous while these were dispersed in the exfoliated form, proving the effectiveness of the modifier. The influence of OMMT nanomaterials on the thermal behaviour of PET and its non-isothermal crystallization was studied. Furthermore, the crystallization kinetics of PET and its nanocomposites were investigated by DSC. The activation energy was calculated using the Friedman's method. The Avrami exponent was calculated and analyzed. The effect of OMMT nanoparticles on spherulite growth rate of PET in all nanocomposites was also evaluated using the modified Lauritzen–Hoffman equation. From all these results it was found that OMMT nanoparticles can act as nucleating agents enhancing the crystallization rate of PET. The dispersion of OMMT nanoparticles in exfoliate form plays also an important role.


► The melting temperature of the nanocomposites was shifted slightly to higher temperatures.
► OMMT can act as nucleating agent.
► The samples present lower activation energy compared to that of neat PET.
► They crystallized by mechanisms with different activation energies.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Thermochimica Acta - Volume 521, Issues 1–2, 10 July 2011, Pages 161–169
نویسندگان
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