Study On The Structure And Properties Of Zirconium Phosphate(Phosphonate)/Polymer Nanocomposites

In the field of polymer composites, polymer-inorganic fillers composites have attracted substantial interest because natural or synthetic inorganic compounds are incorporated in the polymer matrices to improve their mechanical enhancement, or enhance other properties such as electrical conductivity, barrier properties, thermal resistance, etc. Unfortunately, these inorganic fillers based composites are usually immiscible, resulting in serious phase separation, low interfacial adhesion. In order to improve the compatibility between polymer matrices and inorganic fillers, the synthesis of appropriate surface functionalized inorganic particles is accomplished by various methods. Therefore, we synthesized zirconium phosphonates with the organic functional groups and silver carried zirconium phosphates or phosphonates by surface functionalization and assembled functionalization to obtain the high performance polymer products, we carried out the works as follows:(1) Novel castor oil-based polyurethane/a-zirconium phosphate (PU/a-ZrP) composite films with different a-ZrP loading (0-1.6wt%) and different NCO/OH molar ratios were synthesized by a solution casting method. The characteristic properties of the PU/a-ZrP composite films were examined by Fourier transform infrared spectroscopy (FT-IR), thermal gravimetric analysis (TGA), differential scanning calorimetry (DSC), X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and tensile testing. The results from Fourier transform infrared spectroscopy indicated that strong intermolecular hydrogen bonding formed between a-ZrP and PU, XRD and SEM results revealed that the a-ZrP particles were uniformly distributed in the PU matrix at low loading, and obvious aggregation existed at high loading. Due to hydrogen bonding interactions, the maximum values of tensile strength were obtained with0.6wt%a-ZrP loading and1.5of NCO/OH molar ratio in the matrix. Evidence proved that the induced a-ZrP used as a new filler material can affect considerably the mechanical and thermal properties of the composites. (2) A new type of layered zirconium glycine-N,N-dimethylphosphonate (ZGDMP), with the functional groups—COOH, has been prepared and characterized by X-ray diffraction (XRD), scanning electron microscope (SEM) and transmission electron microscopy (TEM). Situ polymerization method was employed to prepare castor oil-based polyurethane/layered zirconium phosphonate (PU/ZGDMP-n) nanocomposite films. The structure and morphology of ZGDMP in polyurethane matrix have been characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR). The results show that the morphology and properties of PU-based nanocomposites greatly depend on the functional groups—COOH because of the chemical reactions and physical interactions involved. The tensile test shows that the tensile strength and elongation at break for the nanocomposite films increase with the loading of ZGDMP as compared to those of the virgin polyurethane.(3) Three novel organic-inorganic hybrid molecules, layered zirconium phosphates or phosphonates, were synthesized. To study the effects of organic chain length of them on the structure and properties of polymer nanocomposites, the polyurethane/a-zirconium phosphate (PU/ZrP), polyurethane/zirconium2-aminoethylphosphonate (PU/ZrAEP) and polyurethane/zirconium2-(2-(2-(2-aminoethylamino)ethylamino)ethylamino) ethylphosphonate (PU/Zr(AE)4P) nanocomposites were prepared, and characterized by Fourier transform infrared (FT-IR) spectroscopy, wide-angle X-ray diffraction (XRD), transmission electron microscopy (TEM), thermal gravimetric analysis (TGA), differential scanning calorimetry (DSC) and tensile testing. It was revealed that morphological, mechanical, and thermal properties of these nanocomposites were strongly dependent on the organic chain length of the layered zirconium phosphonates. The results showed that the fillers with longer chain length exhibited better dispersion in the PU matrix. As expected, the mechanical properties and water resistance were improved with the increasing of organic chain length of fillers, which attributed to better interfacial adhesion between fillers and PU matrix.(4) In this work, the effects of a novel layered silver-carried zirconium (glycine-N, N-dimethylenephosphonate)(Ag-ZGDMPP) nanoparticles on the antimicrobial activities, structure and properties of chitosan-based films (CS/Ag-ZGDMPP-n) were investigated. Fourier-transform infrared spectroscopy (FTIR), X-ray diffractions (XRD), scanning electron microscopy (SEM), thermal gravimetric analysis (TGA), UV-vis absorption spectroscopy (UV-vis), tensile testing, moisture uptake and antibacterial tests are used to study the structure and properties of these nanocomposites. In order to indicate the effect of Ag+, some results of the properties of chitosan/zirconium (glycine-N, N-dimethylenephosphonate)(CS/ZGDMPP-n) were selected for control experimentation. The results showed that the chitosan-based films (CS/Ag-ZGDMPP-n) exhibited a good inhibition effect on the growth of Escherichia coli and Staphylococcus aureus and its ability was attributed to the antimicrobial activity of Ag-ZGDMPP nanoparticles. The composited films exhibited more effective antibacterial activity for Staphylococcus aureus. And the thermal and mechanical properties of CS/Ag-ZGDMPP-n nanocomposites were improved. Our findings reveal that Ag-ZGDMPP nanoparticles have a good potential to be filled in a plastic film to make antimicrobial packaging against bacteria such as Escherichia coli and Staphylococcus aureus.