THERMOGRAVIMETRY OF PHENOL-FORMALDEHYDE POLYCONDENSATES. PART 2. EMPIRICAL KINETIC PARAMETERS
Abstract
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 -(dw/dt) = (w to the nth) A exp (-E/RT) were n = 0-5, A = 0.2 to 1.7 x 10 to the 16th power 1/min, E = 3.7- 72kcal/mole, 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.
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 01, 1967
- Accession Number
- AD0652844
Entities
People
- R. W. Farmer
Organizations
- Air Force Research Laboratory