Study On Crystallization Kinetics And Flow Characteristics Of Plasticized Poly(Lactic Acid)

In the thesis, four plasticizers screened through the experiments were used to plasticize Poly(lactic acid)(PLA). The isothermal crystallization kinetics and nonisothermal crystallization kinetics of plasticized PLA were studied by differential scanning calorimetry (DSC). The spherulite morphology of PLA and plasticized PLA was investigated by polarized light microscope (PLM). And the flow characteristics of these materials were researched by Capillary rheometer.The isothermal crystallization kinetics and nonisothermal crystallization kinetics of plasticized PLA were studied by DSC at first. As the results of Avrami equation, four plasticized materials had same Avrami kinetic parameters, but their crystallization rates and activation energys were very different and PEG advances the crystallization rate of PLA very obviously. Their crystallization behaviors under different cooling rate were analyzed. It was found that Jeziorny equation, Ozawa equation and D-t relation methods were all suit them, and crystallization kinetics parameters were figured out on the basis of experimentsThrough the PLM, it was found that PEG was able to improve the helix twist of chip of PLA spherulite so that the banded spherulites of PLA were very frequent. Some concentric rings looked like cracks were easy to...