Preparation And Behaviors Of Polymer/TiO₂ Hybrid Films And Multi-layer Hybrid Microspheres

Polymer/TiO₂ hybrid materials were an even multiphase material with the advantage properties over polymer and TiO₂, which were widely used in optics, magnetism, electricity and so on. In this paper, a series of Polymer/TiO₂ hybrid materials were prepared. The hybrid and polymerization mechanisms, the structures and properties of them were investigated. The main work as follows:1. KH570-g-TiO₂ particles were synthesized through hydrolysis condensation of KH-570 and Tetrabutyl Titanate(TBNT). Core-shell PBA/TiO₂ hybrid latex was prepared by emulsion polymerization with KH570-g-TiO₂ as seeds and butyl acrylate as the monomer of shell. The hybrid films were successfully prepared on the glass substrate and characterized by FT-IR, TGA, DSC, UV and TEM. The results showed that the condensation reaction between the hydroxyl groups of the hydrolysis of KH-570 and TiO₂ surface carried out, meanwhile PBA were grafted on the surface of KH570-g-TiO₂ particles. The thermal decomposition temperature and glass transition temperature of the hybrid films was 99.7℃, 5℃and organic-inorganic composites have better compatibility. The TiO₂ nanoparticles grafted with PBA appeared even microsphere and the average size of the hybrid microspheres were 100nm. Compared with Poly(butyl acrylate) film, PBA/TiO₂ hybrid film absorbed ultraviolet light well and the red shift of the absorption bands occurred. The performance test of latexes manifested that the hybrid latexes had a better gel rate, high viscosity, water absorption rate and a high stability more than PBA latexes.2. Core-shell PSt/TiO₂ hybrid microspheres (PTHM) were prepared by emulsion polymerization with KH570-g-TiO₂ as seeds and styrene as the monomer of shell and studied by FT-IR, TGA, DSC and TEM. The mechanism of reinforcing PP and the morphology in the PP masterbatch were clarified by SEM. The results indicated that PSt were grafted on the surface of KH570-g-TiO₂ particles. The thermal decomposition temperature and the glass temperature of the microspheres were 242℃, 179℃respectively. The layer average thicknesses of TiO₂ and PSt of the PTHM with narrow size distribution were 60nm and 30nm. SEM and the date of mechanical properties manifested that the PTHM could be dispersed in the PP masterbatch and had better reinforcement to PP. When the content of PTHM was 4wt%, compared with PP masterbatch, the tensile strength and the bending strength of PP/PTHM composite materials were improved by 20.2% and 20.8% respectively, while the tensile elongation were decreased by 7.4% and the impact strength had no chance.3. KH570-g-TiO₂ sol particles were encapsulated with styrene, subsequently with vinylpyrrolidone in the medium of ethyl acetate. The multi-layer hybrid microspheres (PVP/PSt/TiO₂) were characterized by FT-IR, TGA, DSC, TEM and UV. The results testified the decomposition temperature of PVP/PSt/TiO₂increased by 12℃than PSt/TiO₂. The average size of the PVP/PSt/TiO₂ was 3.62μm with uneven distribution and the layer thicknesses of PSt, PVP on the surface of TiO₂ particles were about 60nm and 120nm. The absorbance of the PVP/PSt/TiO₂ measured by UV reduced and the red shift of the absorption bands existed. Compared with TiO₂ sol particles, the dispersion properties of PVP/PSt/TiO₂ in the deionized water had a clear improvement, which provided experimental and foundmental theory to preparation and application of multi-layer hybrid microspheres.4. The PVP/TiO₂ core-shell hybrid microspheres were synthesized through the copolymerization of the KH570-g-TiO₂ sol particles and vinylpyrrolidone and studied by FT-IR, TGA and TEM. The results testified the PVP/TiO₂ hybrid microspheres with even size distribution have a good heat resistance. The average layer thickness of TiO₂ nanoparticles, PVP were 60nm, 20nm, respectively. Compared with TiO₂ sol particle, the dispersion properties of the hybrid microspheres dispersed in the deionized water had a clear improvement.