Research On The Effects Of Nucleating Agents On The Crystallization Behaviors, Crystallization Morphology And Crystallization Structure Of Pet

In this paper, the effects of four kinds of nucleating agents such as:N-A,LCD VectraA950,talc,EBS on the crystallization behaviors, crystallization morphology and crystallization structure were systematic studied. The crystallization behaviors of PET/nucleating agent blends by Differetical Scanning Calorimetry(DSC), and the kinetics of PET crystallization were analysised by Jeziorny theory; The crystallization morphology and crystallization structure of PET/nucleating agent composites were inverstigated by Polarizing Optical Microscope(POM),Small Angle Laser Scattering(Sals) and X Ray Diffraction(XRD),respectively.According to DSC, the glass trasition temperature and the temperature of cooling crystallization decreased by adding these four nucleating agents, while the heating crystallization temperature and melting temperature were increased; at the same time,the apparent induction period,the half time of crystallization,the apparent total time of crystallization of PET/nucleating agents blends were shorter than pure PET;Non-isothermal crystallization kinetics of PET/nucleating agents blends were studied by Jeziorny thory, the results showed that Avrami constant n decreased and the crystallization Zc increased with nucleating agents adding.These were indicated that the added of nucleating agents promoted the nucleating of PET, shorten the crystallization time of PET, among which nucleating agent N-A was the best one.The results of the study on crystallization morphology of PET/nucleating agent composites by POM indicated that four nucleating agents all increased the density of nucleating, lessened the size of crystals, and the crystals were distributed more evenly;The effects of adding four nucleating agents on the crystal size and the induction time of crystallization were quantitative anlysisted by Sals, the results show that these four nucleating agents all can lessened the size of crystals,shortened the induction time of crystallization of PET,accelerated the nucleation and promoted the crystallization of PET. Nucleating agent N-A was the best of these four. Crystallization structure of PET/nucleating agents composites were analysised by XRD, the results showed that crystal cells were not changed, but the average size of crystals which perpendiculared to the crystal surface [010],[100]were lessened, while the total degree of crystalinity was largered,which also indicated that it could lessened the size of crystal and promote the crystallization of PET by adding nucleating agents.The effects of four nucleating agents on PET crystallization behaviors, crystallization morphology and crystallization structure were amprehensive considerated, finally we found nucleating agents N-A was the best nucleating agent for crystallization of PET, followed by tacl,LCD VectraA950 and EBS was the last.