Abstract
The thermal stability of poly(diallyldimethylammonium chloride) (PDMDAAC) with serial molecular weights Mw ranged from 0.2850 × 106 to 1.144 × 106 was determined by TG-DSC. The decomposition activation energy of PDMDAAC, with different molecular weight was from 83.42 to 98.53 kJ/mol in Step I and from 163.63 to 223.68 kJ/mol in Step II, was obtained from TG with different heating rates, using the methods of Coats-Redfern and Ozawa. The evaluated decomposition activation energy Ea of PDMDAAC with Mw of 1.144 × 106 calculated by Ozawa method was 124.1 and 211.1 kJ/mol for each decomposition step, respectively. The results indicated that there were two decomposition steps for polymer PDMDAAC, while there was only one for its monomer DMDAAC. The calculation results by using the Coats-Redfern method indicated that the reaction order for two decomposition steps of PDMDAAC was both one. The Ea increased with the molecular weight of linear PDMDAAC. The thermal characteristic of crosslink products was more stable than the linear product.
Acknowledgments
The authors are thankful for the financial support from the National Natural Science Foundation of China (51503100 and 21377054).
Conflict of interest
The authors declare that they have no competing interests.