Heat treatment characteristics and kinetics of typical biodegradable plastics
In order to explore the characteristics of biodegradable plastics in the heat treatment process,the weight-loss characteristics of biodegradable plastics(BP1)composed of the polylactide(PLA)and Poly(butyleneadipate-co-terephthalate)(PBAT)were analyzed by thermogravimetric analyzers at different heating rates(10,20 and 30℃/min),and the reaction process of BP1in nitrogen atmosphere and air atmosphere was not completed in one step,and there were obvious two-step weight-loss processes in the main reaction stages.The mass loss rates of the two main reaction stages under nitrogen and air atmosphere reached 87.99％～89.64％and 84.99％～86.88％,respectively,and there was obvious overlap between the temperature ranges of the two reaction stages.The kinetic parameters were calculated by using iso-conversional method of Flynn-Wall-Qzawa(FWO)、Kissinger-Akahira-Sunose(KAS)、Starink,and the average activation energy E of BP1in stage 1 and stage 2 under nitrogen atmosphere was 88.95 and 90.92kJ/mol,respectively,and the average activation energy E of stage 1 and stage 2 under air atmosphere was 67.23 and 91.27kJ/mol,respectively.The kinetic reaction mechanism was determined by Master-plots method based on 10℃/min,which showed that main reaction stage of BP1 conformed to the random nucleation and nuclear growth model(An),but the number of reaction stages was different,indicating that the different atmospheres of nitrogen and air did not affect its reaction mechanism,but the generation and inactivation rate of the active point were different.
biodegradable plasticsheat treatment characteristicskineticsiso-conversional methodmechanism model
万方数据
维普
