Ignition Hardening of Cellulosic Materials
Abstract
The ignition response of blackened alpha-cellulose and cotton cloth, containing fire retardant additives, was compared to the ignition response of these materials without additives. This information was obtained by exposing the samples to various irradiance levels from a calibrated thermal radiation source. Samples treated with retardant compounds which showed the most promise were then isothermally pyrolyzed, in air, so that comparisons between the pyrolysis rates of the samples could be obtained. These comparisons yielded further insight into the mechanism of thermal degradation. Similar ignition response measurements were made with specimens exposed to ionizing radiation. Alpha-cellulose samples containing a mixture of boric acid, borax, and ammonium di-hydrogen phosphate could not be ignited by irradiances up to 4.0 cal cm (exp -2) sec (exp -1). Above this value, transient ignition would occur but flaming would last only until the ignitible gases were exhausted from the samples. Cotton cloth containing a polymeric retardant with the designation THPC + MM was found to be ignition resistant below an irradiance of 7.0 cal cm (exp -2) sec (exp -1). Comparison of the pyrolysis rates of the retardant treated alpha-cellulose and cotton showed that the retardant mechanism is qualitatively the same. It was also found that gamma radiation results in ignition retardance of cellulose, while irradiation by neutrons, does not.
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 10, 1967
- Accession Number
- AD0663086
Entities
People
- Norman J. Alvares
- Thomas H. Anderson
Organizations
- Naval Radiological Defense Laboratory