TY - JOUR
T1 - Porosity development in chars from thermal decomposition of poly(p-phenylene terephthalamide)
AU - Castro-Muñiz, Alberto
AU - Martínez-Alonso, Amelia
AU - Tascón, Juan M.D.
N1 - Funding Information:
A.C.-M. acknowledges receipt of a I3P pre-doctoral contract from CSIC. Financial support from the Spanish MEC (project CTQ2005-09105-C04-02) and CSIC (project PIF08-009-2) is gratefully acknowledged.
PY - 2009/10
Y1 - 2009/10
N2 - 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.
AB - 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.
KW - Adsorption
KW - Chars
KW - Poly(p-phenylene terephthalamide)
KW - Porosity
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U2 - 10.1016/j.polymdegradstab.2009.06.017
DO - 10.1016/j.polymdegradstab.2009.06.017
M3 - Article
AN - SCOPUS:80051668338
VL - 94
SP - 1890
EP - 1894
JO - Polymer Degradation and Stability
JF - Polymer Degradation and Stability
SN - 0141-3910
IS - 10
ER -