THERMOGRAVIMETRY OF PHENOL-FORMALDEHYDE POLYCONDENSATES. PART 2. EMPIRICAL KINETIC PARAMETERS
Technical rept. May 1965-Sep 1966
AIR FORCE MATERIALS LAB WRIGHT-PATTERSON AFB OH
Pagination or Media Count:
Empirical kinetic parameters for phenol-formaldehyde polycondensate materials were surveyed for general application to Air Force interests. The ranges of n, A, E for the empirical kinetic model -dwdt w to the nth A exp -ERT were n 0-5, A 0.2 to 1.7 x 10 to the 16th power 1min, E 3.7- 72kcalmole, where w is normalized weight, t is time, R is gas constant, T is temperature. The mass spectrometry and thermogravimetry thermal analysis methods used both constant heating rate and isothermal approaches. Reexamination of data with a new computer program gave reduced variations n 1.56 plus or minus 0.07, A 60.9 plus or minus 41.4, E 10.38 plus or minus 1. 20. The scopes of the comprehensive survey and descriptive thermogravimetry computer analysis were 22 constant rate 3 isothermal vs 6 constant rate experiments by 8 vs 3 investigators using 5 cured 7 vitreous fiber reinforced vs 4 cured polycondensates. Parameter inconsistencies for the survey were partially associated with an atypical polycondensate, laminate and polycondensate particle or laminate powder samples, or a reduced pressure atmosphere. Calculated parameters apparently dependent upon the two latter aspects were not averaged with other values. Small curve-fitting and other errors potentially enhance further disagreement as they often gave large parameter variations.
- Polymer Chemistry
- Laminates and Composite Materials
- Atomic and Molecular Physics and Spectroscopy