The Aqueous Dispersions of Bicontinuous Cubic Phases Formed by Precursor Method

The morphologies and the microstructures of the dispersed particles of the cubic phase, which were formed by precursor method, were studied. The freeze-fracture TEM clearly showed that the aqueous dispersed particles have irregular cubic shapes. X-ray diffraction technique has been utilized to study the microstructure of the particles and it was found that these particles still retained the cubic character. The sizes of the particles were measured by dynamic light scattering, and the results showed that the sizes of the dispersed particles were between 200 ~ 400 nm under different conditions.

Preparation and Characterization of Hybrid Aqueous Dispersions Composed of Silica Sol and Poly(styrene-co-acrylate)

A stable silica sol with 3-5 nm in diameter, which can form homogeneous film without crack, was prepared and characterized. Then, the inorganic-organic hybrid aqueous dispersion composed of such a silica sol and an emulsion of styrene （St） and acrylate （Ac） copolymer was prepared and the hybrid effect between the silica sol and poly（St-co-Ac） was observed by Fourier transform infra-red （FT-IR） spectroscope. The toughness of the film prepared by this kind of hybrid aqueous dispersion was excellent, as it was enhanced appreciably by commixing with a small amount of poly（St-co-Ac） emulsion. Some amino-polysiloxane modified hybrid aqueous dispersions were also prepared and the properties of the modified dispersions and their films were investigated. The experimental results showed that the film prepared with such an amino-polysiloxane modified hybrid dispersion exhibited excellent hydrophobicity and low surface energy after heat treatment for 1.5 h, during which the formation of the graft copolymer was observed. The surface energy of this film decreases as a result of the enrichment of siloxane segments on the film surface.

Synthesis of a Novel UV Curable Aqueous Dispersion Polyurethane PDHA-PEDA-PU and the Properties of Cured Film

A novel ultraviolet （UV） curable aqueous dispersion polyurethane PDHA-PEDA-PU was synthesized based on isophorone diisocyanate （IPDI）, polyester dihydric alcohol （PDHA）, dimethylol propionic acid （DMPA）, pentaerythritol diacrylate （PEDA）, 2-hydroxyethyl acrylate （HEA） and triethylamine （TEA）. Acrylate groups were incorporated in the side and end of PDHA-PEDA-PU chain. The C=C content in the chain can be controlled easily through the change of IPDI/PDHA/PEDA ratio. Fourier transform infrared spectroscopy （FTIR） was used to identify the structure of prepolymer, aqueous dispersion and cured polyurethane. The curing rule of the polyurethane for different C=C content has been investigated depending on the change of C=C content during the curing process. The hardness, thermal stability and scrub resistance to MEK of UV cured PDHA-PEDA-PU were also discussed for the samples with different C=C content.

Synthesis and Characterization of a Novel Aqueous Dispersion Poly[urethane-(disperse blue 14)-urethane] Dye

A novel polymeric dye of aqueous dispersion poly[urethane-(disperse blue 14)-urethane] was synthesized based on poly(propylene glycol) (PPG), 2, 4-tolylene diisocyanate (TDI), klimethylol propionic acid (DMPA), disperse blue 14 and triethylamine (TEA) depending on a modified acetone process. Fourier transform infrared spectroscopy (FTIR) was used to identify Lhe structure of the polymeric dye, indicating an obvious carbonyl stretching absorption in disperse blue 14. The polymer was also characterized by the analysis of DSC, TGA, WAXD and UV-Vis spectroscopy.

Effect of Carbon Particles with Different Topological Shape on the Rheological Behavior of PVA Aqueous Dispersion

Poly(vinyl alcohol)(PVA)is usually processed and used in a form of aqueous dispersion.A large number of inter-and intramolecular hydrogen bonds make it very difficult to obtain suitable rheological behavior for processing.In this study,carbon particles with different topological shapes were added into PVA aqueous dispersion to tune the steady and dynamic rheological behavior.The results show that the zero-dimensional particles(carbon black,CB)increase monotonically the zero-shear viscosity of PVA dispersion,while the one-dimensional particles(carbon nanotubes,CNTs)make it first increase,and then decrease and rise again,like an N-shape,and the two-dimensional particles(graphene oxide,GO)can make it first decrease and then increase,exhibiting a U-shape.It is believed that the topological shape of the carbon particles brought about these discrepancies.The zero-dimensional particles mainly act as physical crosslinking points due to their small size.While at a certain content,both CNTs and GO can destroy the intermolecular hydrogen bonds between PVA chains because the PVA chains can twine around the slim CNTs and the large planar size of GO prevents the adsorbed PVA from forming hydrogen bond with other chains.The high hydroxyl value of carbon particle surface could strengthen this effect.It is expected that the viscosity of polymer dispersion can be regulated by particles with different topological shape and the surface characteristic,so as to widen the operable concentration range during preparing composite functional materials.

A personal journey on using polymerization in aqueous dispersed media to synthesize polymers with branched structures

This short review is dedicated to celebrate Prof.Shoukuan Fu’s 80 th birthday by discussing several of my accomplished projects over the past twenty years,which all applied radical polymerization in aqueous dispersed media for producing polymers with branched structures.These projects include the use of microemulsion polymerization for syntheses of fluorescent nanoparticles,hairy nanoparticles and hyperbranched polymers;the use of miniemulsion polymerization for synthesis of star polymers and light-emitting nanoparticles;the use of seeded emulsion polymerization for synthesis of hairy nanoparticles and hyperstar polymers;and the use of precipitation polymerization for synthesis of hollow polymer nanocapsules.Discussion of these projects demonstrates intriguing features of polymerization in biphasic dispersed media via either conventional radical polymerization or controlled radical polymerization to effectively regulate the branched structure of functional polymers.