Thermal decomposition mechanism of poly(dimethyldiallylammonium chloride)

The thermal decomposition mechanism of polydimethyldiallylammonium chloride (PDMDAAC) was studied innovatively. The bond breaking sequence of PDMDAAC in thermal environment was evaluated by quantum chemical calculation, then thermal decomposition mechanisms of PDMDAAC were speculated which were clarified by TG-DSC-MS and FTIR. The TG-DSC curves showed PDMDAAC has two stages of thermal decomposition. B3LYP/6-31G* method was used to calculate the E-a (activate energy of the bond breaking) of each type of the bonds breaking. The simulation results indicated that C-N was the most easily broken bond in the cyclic five member ring, and the evaluated E-a was 184.23 kJ mol(-1). The results illustrated that TG-DSC-MS and FTIR spectra verify the hypothesis that the ring C-N bond breaks firstly. The main gas products in the two stages of PDMDAAC thermal decomposition are NH2Cl and CH4, C2H2, C3H8, respectively.

Automated summary

The thermal decomposition mechanism of PDMDAAC was studied using quantum chemical calculation and experimental methods, revealing that the C-N bond in the cyclic five member ring is the most easily broken bond. The thermal decomposition process occurs in two stages, leading to gas products NH2Cl, CH4, C2H2, and C3H8.