کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5204011 | 1381946 | 2009 | 5 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Porosity development in chars from thermal decomposition of poly(p-phenylene terephthalamide)
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
شیمی
شیمی آلی
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چکیده انگلیسی
The main objective of this work was to investigate the development of porosity in solid residues from the thermal decomposition of the polymer, poly(p-phenylene terephthalamide) (PPTA). PPTA chars were prepared at different temperatures and characterized by X-ray diffraction and physical adsorption of CO2 at 0 °C. The carbonization temperatures were selected on the basis of thermogravimetric analysis results. The effect of introducing an isothermal treatment at 500 °C on the characteristics of the resulting chars was also studied. It was found that this pre-treatment lowers the decomposition temperature of PPTA and yields a somewhat less ordered material than in the case of pyrolysis under a constant heating rate. The micropore volume increases with increasing heat treatment temperature for both series of samples. The mean micropore size decreases for the two series of chars until the 700-800 °C interval; above these temperatures, this evolution is reversed. The micropore volume of the samples submitted to the isothermal treatment is higher than when PPTA is treated under a constant heating rate. Likewise, the pore size distribution is more heterogeneous when the intermediate isothermal treatment at 500 °C is introduced during PPTA pyrolysis. Some differences between porosity development in chars from PPTA and other high thermal stability polymers were explained on the basis of different mechanistic features in polymer pyrolysis.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Polymer Degradation and Stability - Volume 94, Issue 10, October 2009, Pages 1890-1894
Journal: Polymer Degradation and Stability - Volume 94, Issue 10, October 2009, Pages 1890-1894
نویسندگان
Alberto Castro-Muñiz, Amelia MartÃnez-Alonso, Juan M.D. Tascón,