Preparation Of LDHs/polyester Nanocomposites And Their Crystallization Kinectics

Now days, result from the applications of the polyester is being developed. The necessities of preparing physical enhanced and special functioned, such as flame retardant, antistatic and antibacterial, polyester are increasingly important. Layer double hydroxides (LDHs) may be a suitable solution. LDHs are novel layer clay material combined by positive double metals’ ion layer and negative interlayer ion. Researchers can synthesize various functioned LDHs by controlling the species and ratios between positive metals’ ions and negative interlayer ions. So, LDHs have increasing potential applications, such as catalytic, fluorescent, electromagnetic and polymer enhancing applications.In this paper, in order to combine the advantages between LDHs and polyester to supply relatively economical solutions for the issues narrated before, we synthesized various organically modified LDHs and composited these LDHs with various polyester materials by applying melting blending. So, we have concluded several results as below.Firstly, the anionic surfactants inserted then toluene diisocyanate grafted LDHs were synthesized and the insertion and the grafting were successful. The X-ray diffraction analysis (XRD) to the products revealed that the layer lengths of various LDHs were increased significantly, which means that all the anionic surfactants were inserted into LDHs layer. Furthermore, the Fourier transform infrared analysis (FTIR) discovered that the grafted LDHs existed N-H groups and C=O groups on the surfaces, which proved that the TDI grafted on the layer surfaces. Also, the TG-IR analysis detected the-NCO groups grafted on the LDHs were revived at around 180℃, which indicated that the grafted LDHs had latent reaction ability.Secondly, the fluorescence analysis for tracking the synthesis procedures of LDHs-DS with various concentrations of SDS and the micelle forms of SDS in the synthesis system also showed the specify micelle structure might promote and guide the growing of the LDHs, which result from the intense variety of the fluorescence intension. Because the fluorescence intensity of LDHs synthesis systems varied by following the increasing of SDS concentration, which from strong to weak then fairly strong. The fluorescence analysis to the SDS/H2O/alcohol solutions also revealed this result.Lastly, the LDHs/PTT and LDHs/ABS/r-PET nano composites were prepared by using melting blend method and the crystallization analysis to these composites was also operated. For the LDHs/PTT nano composites, the delicate effects from the LDHs to the PTT were detected. The XRD analysis revealed that the LDHs had inconspicuous affect the crystal structure of PTT. But the non-isothermal crystallization kinetic analysis, which gained by DSC, indicated the KAvrami decreased significantly, but the n had no significant changes. It’s revealed that LDHs decelerated the crystallization rate of the PTT. But the nucleation mechanism of PTT didn’t be interfered. In contrast, LDHs varied the nucleation mechanism of the r-PET in the LDHs/ABS/r-PET. XRD and DSC analyses indicated that the LDHs also had similar effects to the crystal structure and KAvrami to the LDHs/ABS/r-PET nano composites. But LDHs also increased the n, which means that LDHs varied the nucleation mechanism conspicuously.