Accession Number:

AD0652844

Title:

THERMOGRAVIMETRY OF PHENOL-FORMALDEHYDE POLYCONDENSATES. PART 2. EMPIRICAL KINETIC PARAMETERS

Descriptive Note:

Technical rept. May 1965-Sep 1966

Corporate Author:

AIR FORCE MATERIALS LAB WRIGHT-PATTERSON AFB OH

Personal Author(s):

• Farmer, R. W.

Report Date:

1967-03-01

Pagination or Media Count:

73.0

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 -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.

Descriptors:

• *PHENOLIC PLASTICS
• *HEAT SHIELDS
• MECHANICAL PROPERTIES
• THERMAL STABILITY
• MASS SPECTROSCOPY
• THERMOGRAVIMETRIC ANALYSIS
• LAMINATED PLASTICS
• REINFORCED PLASTICS
• ABLATION
• COMPUTER PROGRAMS
• THERMOCHEMISTRY

Subject Categories:

• Polymer Chemistry
• Laminates and Composite Materials
• Atomic and Molecular Physics and Spectroscopy

Distribution Statement:

APPROVED FOR PUBLIC RELEASE