Thermal Degradation of Piperazine Copolyamides
The thermal degradation of piperazine copolyamides was studied by both programmed and isothermal techniques with a Cahn RG Electrobalance® using a modified hangdown tube and thermocouple assembly. Experiments were carried out with block copolymers of terephthaloyl trans-2,5-dimethylpiperazine / isophthaloyl trans-2,5-dimethylpiperazine (abbreviated as t-2,5-DiMePipT / t-2,5-DiMePip-I), terphthaloyl trans-2,5-dimethylpiperazine / sebacyl trans-2,5-dimethylpiperazine (abbreviated as t-2,5- DiMePip-T / t-2,5-DiMePip-10), and isophthaloyl trans-2,5-dimethylpiperazine / sebacyl trans-2,5-dimethylpiperazine (abbreviated as t-2,5-DiMePip-I/t-2,5-DiMePip-10). In contrast to the previously studied homopoljrmers, the activation energies (range 44 to 61 kcal/mole), rates of volatilization, and half-life values are influenced by the molecular weights of the block copoljrmers. In general, the data indicate a random degradation process during isothermal pyrolysis in a vacuum. The exception is the block copolymer of t-2,5-DiMePip-I/t-2,5-DiMePip-10, which shows the competing effect of hydrolytic processes.
KeywordsBlock Copolymer Thermal Degradation Number Average Molecular Weight Tungsten Lead Dimethyl Pyrazine
Unable to display preview. Download preview PDF.
- 5.P. W. Morgan and S. L. Kwolek, J. Polymer Sci., A2, 181 (1964).Google Scholar
- 7.S. Straus and L. A. Wall, J. Res. Natl. Bur. Std., 60, 39 (1958).Google Scholar
- 8.S. Straus and L. A. Wall, J. Res. Natl. Bur. Std., 63A, 269 (1959).Google Scholar
- 9.S. L. Madorsky, Thermal Degradation of Organic Polymers, Interscience Publishers, New York (1964).Google Scholar