Xiaorong Wang

Synthesis and Mechanical Properties of Membranes Prepared from Hydroxyl-Terminated Polyurethane Alcohol Dispersion Modified by Epoxy Resin

Hydroxyl-terminated polyurethane (EPPU) modified by epoxy resin was synthesized. The structure of polyurethane (PU) was characterized by Attenuated total reflection Fourier transform infrared spectrometer (ATR-FTIR) and transmission electron microscope (TEM). The effect of w(E-44) on thermal stability and mechanical properties of the membranes were also measured. ATR-FTIR and TEM indicates that epoxy resin has been successfully incorporated into the copolymers main chain, and the thermal stability has improved. It was found that greater mechanical properties of PU were obtained when chemical networks were formed between PU and epoxy resin. The maximum tensile strength is up to 6.99 MPa.

Synthesis and characterization of self-crosslinked polyurethane/polyacrylate composite emulsion based on carbonyl–hydrazide reaction

Self-crosslinkable aqueous polyurethane (PU)/polyacrylate (PA) composite emulsion was obtained by radical copolymerization. Fourier transform infrared spectroscopy (FT-IR) result shows that the cross-linking reaction between the carbonyl group and the hydrazine group has happened. The influence of the hydrazide-carbonyl molar ratio and the PA content on the properties of the composite emulsions and their films were investigated. The results show that, under the optimal hydrazide-carbonyl molar ratio (n (hydrazine group)/n (carbonyl group) =1:1), the water absorption is 10.56xa0%, and the mechanical properties and thermal stabilities are both improved. As the PA content increases from 0xa0wt% to 15xa0wt%, the tensile strength increases from 5.7xa0MPa to 7.3xa0MPa and the gel content increases from 70.3xa0% to 87xa0%.

Micromorphology and thermal properties of polyurethane/polyacrylate soap-free emulsion in the presence of functional monomers

Novel polyurethane/polyacrylate (PUA) composite emulsions were synthesized by soap-free emulsion polymerization method from methyl methacrylate (MMA), butyl acrylate (BA), and 2-Hydroxyethyl acrylate (HEA) in the presence of PU as seeds and a polymerizable emulsifier-Allyloxy hvdroxyl propanesulfonic salt (AHPS). Effects of the AHPS content on the properties of the emulsions and films were studied. Dynamic light scattering (DLS) result showed that the average diameters and polydispersity were decreased with the increment of AHPS content. Fourier transform infrared spectroscopy (FT-IR) result shows that AHPS was introduced into the PUAS chains. Their thermal stability and Tg of the films increased gradually with augment of AHPS amount in polymer. X-ray photoelectron spectroscopy (XPS) analysis showed that sodium was preferably enriched on the surface of latex particles. Atomic force microscopy (AFM) observation performed the extremely flat membrane.

Surface Properties and Application of Fluorinated Emulsifier-Free Emulsion Surface Sizing Agent

Fluorinated emulsifier-free emulsion surface sizing agent (FEE) was prepared by emulsifier-free polymerization of hexafluoro-butyl methacrylate (FA), styrene (St) and so on in the presence of fuorinated random amphiphilic polymers (ASRF) copolymerized by FA, St and acrylatic acid. Effects of ASRF content and treatment temperature on the surface properties of the films were investigated. Effects of ASRF content and oxide starch on the application were also discussed. Additionally, fiber morphologies of the samples were characterized by SEM.The results show that the appropriate increases of ASRF content and treatment temperature are good for the decreases of surface free energies of the films. When the ASRF content and oxide starch content is 5% and less 50% respectively, the FEE and its combination with oxide starch have good sizing performance. After the treatment by FEE, the fiber surface becomes smooth, which provides lower surface free energy of the fibers.

Micromorphology and adhesive properties of sulfonated polyurethane/polyacrylate emulsions prepared by surfactant-free polymerization

Novel eco-friendly sulfonated polyurethane/polyacrylate (SPUA) emulsions were synthesized by surfactant-free emulsion polymerization method using PU as seeds. The sodium sulfonate modified polyester polyol (SDNP) was used as internal emulsifier to make the PU emulsion disperse in deionized water. Effects of the SDNP content on the properties of the emulsions and membranes were studied. Dynamic light scattering (DLS) result showed that the average particle sizes of SPUA emulsions decreased first from 124.1xa0nm to 102xa0nm when the SDNP content was lower than 40xa0wt% and then increased to 138xa0nm. Transmission electron microscopy (TEM) morphology showed that the particle sizes were all spherical and an apparent core-shell structure was observed. Fourier transform infrared spectroscopy (FT-IR) result ascertains that SPUA was successfully prepared. X-ray photoelectron spectroscopy (XPS) analysis demonstrates that the carbon, oxygen, nitrogen, sulfur, and sodium peaks were all revealed and the polyurethane component was rich in the upper surface. Thermo gravimetric analysis (TGA) of the membranes showed that the thermal stability of the SPUA membranes was enhanced by increasing the SDNP content. Scanning electron micrograph (SEM) results demonstrates that the coexistence of a dual phase. The SPUA could be used as adhesives in footwear industry, and the T-peel strength of the SPUA membranes increased from 5.98xa0N/mm to 12.06xa0N/mm when the SDNP content was up to 40xa0wt%. The wettability of SPUA emulsions on the rubber surface results showed that the emulsions could wet the rubber surface well.

Research and Application of Ultra Low Interfacial Tension Oil Displacement Agent

ABSTRACT An ultralow interfacial tension (IFT) oil displacement agent, which was a surfactant combinational system (HCS) with good salt and heat resistance, was synthesized using amphoteric betaine (AMS)/anionic sulfonate (AKS)/nonionic alkyl amide (NIS). The interface tensiometer was used to test the IFT. The results showed that the oil–water IFT could be as low as 10−4 mN/m when the salinity is 10,000∼50,000u2009mg/L, the concentration is 1∼5u2009g/L, and the temperature is 40∼80°C. The surfactant system has good emulsification stability. The displacement simulation experiments demonstrated that the increment of the recovery ratio can be up to 14.1%. The surfactant system could meet the demands of site operation. GRAPHICAL ABSTRACT

Preparation and Property of Hydrophobic Modified Guar Gum Thickener

The modified guar gum was synthesized with guar gum as material and bromododecane as etherifying agent by suspension polymerization method. The solution and gel of the modified guar gum were also prepared. The structure and the property of the modified guar gum were analysized by Fourier transform infrared spectrum (FT-IR), X-ray diffraction (XRD) and thermogravimetric analysis (TGA). The heat resistance and the viscoelasticity modulus of the gel were also researched by rheometer. The results of FT-IR and XRD show that the hydrophobic long chain has been introduced into the guar gum successfully. TGA indicates that the modified guar gum has higher thermal stability. The rheology tests reflect that with different temperature conditions, the shear viscosity, the viscoelasticity modulus of the gel and the heat resistance of the modified guar gum are both better than that of the unmodified guar gum. The modified guar gum can be used as thickener of fracturing fluid, and it can reduce its amount.

The Research of Konjac Glucomannan Fracturing System

Fracturing fluid was obtained by putting the organic borate and organic titanium crosslinkers into the base fluid of konjac glucomannan. The properties of the fracturing fluid were also discussed. The system was very stable until the temperature reach to 90°C. The system also performed good shear resistance ability when the shear rate was 170s-1 at 80°C for half an hour. The residue content after gel breaking and the suspended sand performance both satisfied the requirements of the operation.