Thermal decomposition behaviors and kinetics of carrageenan-poly vinyl alcohol bio-composite film

Pyrolysis characteristics of carrageenan-polyvinyl alcohol (CG-PVA) composite films were studied on a thermo gravimetric analyzer in N2 atmosphere. A stepwise procedure based on model-free Flynn-Wall-Ozawa (FWO), Kissinger-Akahira-Sunose (KAS) and Friedman-Reich-Levi (FRL) methods were applied to calculate the apparent activation energies (E). The range of E for CG-PVA/LBP/K film was 16.92∼171.53 kJ/mol. Coats-Redfern and master-plots methods were utilized to investigate the most probable mechanisms for CG-PVA/LBP/K film. Further kinetic analysis was performed and revealed that five independent parallel reactions were supposed reasonably by deconvoluting DTG curves. Kinetic parameters of the corresponding five pseudo-components for CG-PVA/LBP/K film were separately calculated via Kissinger's method using the peak maximum temperature. It's concluded that lignin derivatives contributed the major part of degradation process. The orders of activation energy for pseudo components are E (PVA) > E (carrageenan) > E (biomass derivatives). The comprehensive analysis of pyrolysis kinetics may expand application fields of carrageenan based biocomposite films.