Synthesis And Characterization Analysis Of POSS Hybrid Nanocomposite

It has been the focus to develop low shrinkage dental composite resins in recent years. A major difficulty in developing low shrinkage dental restoration materials is that their deficiently mechanical properties can not satisfy the clinical purpose. In this paper, POSS hybrid dental nanocomposites were synthesized and their microstructures and performances were characterized. Molecular dynamic models of POSS hybrid nanocomposites were constructed. The relationship between dental composite resins'molecular structures and POSS organic-inorganic hybrid nano-system were studied and the major mechanical parameters of POSS hybrid nanocomposites were predicted.Firstly, POSS hybrid nanocomposites were synthesized incorporated with nano multifunctional POSS-methacryl substituted. The relationship between different weight percentage of POSS and the materials'performances such as shrinkage, modulus, strength, hardness and toughness were evaluated. The results showed that with POSS incorporated, the shrinkage of nanocomposites was improved effectively, their mechanical properties were increased greatly, and their wear resistance and service life were enhanced.Fourier-transform infra-red spectroscopy and X-ray diffraction were used to characterize the microstructures and double bond conversion of POSS hybrid nanocomposites. Differential scanning calorimeter was used to study the glass transition temperature. The results showed that the nanocomposites with different weight percentage POSS incorporated were amorphous structures. And the double bond conversion and glass transition temperature of nanocomposite with 2wt% POSS were shown the highest.Furthermore, according to the topology of multifunctional POSS in the polymers and the reactive characters of resin monomers, referenced by double bond conversion, the representatively molecular dynamic models were fabricated in the paper. Compared with X-ray profiles and volume-temperature profiles, the excellent agreement results were got between simulated and experimental datas. It confirmed that the molecular dynamic models we constructed and the calculated methods we used were reasonable and feasible.Finally, radial distribution function, cohesive energy, solubility parameter and mean square displacement of the materials were evaluated by the way of molecular dynamic simulation. The effects of multi-functional POSS-methacrylate on the microstructures and properties of POSS hybrid nanocomposites were analyzed and their important mechanical parameters were predicted. The molecular dynamic simulation results were also analyzed.