Preparation And Structural Properties Of The Polymer / Hydrotalcite-like Layered Double Hydroxide Composites

In this thesis, the preparation, characterization and properties of polymer/layered double hydroxide (LDH) nanocomposites were described. The polymer/LDH nanocomposites were synthesized by solution intercalation and melt intercalation methods. Poly(propylene carbonate)/Mg₃Al LDH, linear low density polyethylene (LLDPE)/ Mg₃Al LDH and Nylon 6/ Mg₃Al LDH exfoliated nanocomposites were prepared. In addition, the synthesis of hydrotalcite based nanocomposite and its flame-retardant and synergistic effect with microencapsulated red phosphorus (MRP) on EVA resin were also investigated.1. The PPC/MgAl-LDH nanocomposites have been successfully synthesized by solution intercalation of PPC chains into organic modified MgAl-LDH interlayers in cyclohexanone. The TGA results demonstrated that only a small amount of OMgAl LDH can increase the thermal stability of exfoliated PPC nanocomposites because the LDH additive not only has the obstruct effect of enhanced thermal stability but also the negative catalytic degradation effect on the PPC resin. The thermal degradation temperature of PPC1 sample with 1% OMgAl LDH was 10 ℃ higher than that of pure PPC resin. The data from the mechanical test showed that the tensile strength of 36.9 Mpa and Yong's modulus of 1303 Mpa for PPC/MgAl-LDH nanocomposite with 5% LDH addition were 72% and 57% higher than those for pure PPC resin.2. LLDPE/MgAl LDH nanocomposites have been prepared by direct melt intercalation of LLDPE in the part organically modified MgAl-LDH, where half of the nitrate anions were replaced by dodecyl sulfate anions. The DSC data indicated that the crystallinity of LLDPE/MgAl LDH nanocomposite increased and thus its endothermic peak temperature was raised by about 5 ℃ with 5 wt% MgAl(H-DS) addition. The TGA profiles of the LLDPE/MgAl-LDH nanocomposites showed a faster charring process between 210 and 370 ℃ and greater thermal stability above 370℃ than pure LLDPE. The thermal decomposition temperature of the nanocomposites with 10 wt% modified MgAl-LDH addition was 42 ℃ higher than...