Comparing Crystallization Kinetics Between Polyamide 6 And Poly Ketone Via Flash DSC

In this work,we employed a commercially available chip-calorimeter(Flash DSC1)to compare the crystallization kinetics between polyamide 6(PA)and polyketone(PK)and discussed the influence of the intermolecular interaction on the polymer crystallization kinetics.In Chapter 1,we introduced the actual process is closely related to the crystallization kinetics due to the complexity of crystallization behaviors on account of the special polymer structure of long chain.The crystallization kinetics is controlled by the thermodynamic and kinetics factors which are usually variable and thus inseparable.However,PA and PK have similar equilibrium melting point and the heat fusion of 100%crystalline phase.Therefore,a comparison between their crystallization kinetics can screen off the thermodynamic factors of intermolecular interaction and expose their kinetics factors.In addition,we introduced some basic concepts of polymer crystallization and melting behaviors,melting reorganization and applications of Flash DSC1.In Chapter 2,we introduced the supplier of samples and the basic data such as melting point and glass transition temperature,as well as the molecular structure and the crystal phase of PA and PK.After the illustration of the operation and performance of Flash DSC 1,we introduced the method to confirm the testing condition and the calculation of half-crystallization time.In Chapter 3,The testing condition and result of isothermal crystallization kinetics were obtained.We compare the kinetics curves and conclude that PA crystallizes faster in the high temperature region and has a weaker temperature dependence due to the strong sheet-like bonding interactions which can lower the free energy barrier for crystal nucleation,in particular,the lateral surface free energy of lamellar polymer crystals.However,PA crystallizes slower in the low temperature as the higher glass transition temperature which bring about a higher diffusion barrier.In Chapter 4,we summarized conclusions above and subjects for future study.