Heqing Fu

The Film Properties of Waterborne Polyurethane Modified by Epoxidized Soybean Oil and Styrene

The waterborne polyurethane (WPU) modified by epoxidized soybean oil (ESO) and styrene (St) (WPU-ESO-St) was synthesized by free-radical emulsion polymerization using styrene (St) as a monomer, and azodiisobutyronitrile (AIBN) as initiator. The research on the mechanical properties of the film showed that with the increasing of the [NCO]/[OH] ratio, the contents of ESO, DAAM and the St, the tensile strength increased, and elongation at break decreased. The surface morphology of the film was characterized by atomic force microscopy (AFM). The glass transition temperature (Tg) of the film was characterized by differential scanning calorimetry (DSC) analysis.

Properties of Aqueous Polyurethane Dispersion Modified by Epoxide Resin and Their Use as Adhesive

The aqueous polyurethane hybrid dispersion modified by the epoxy resin were synthesized using 1,4-butanediol ( BDO ) and dimethylolpropionic(DMPA) as chain extenders. A kind of automobile interior decoration adhesive was made by the modified hybrid dispersions. Effects of the content and the kinds of epoxide resin on the properties of dispersions and dispersion-cast films such as appearance, pot life, viscosity, particle size, molecular mass, hardness, swelling in water, contact angle, strength of stress, elongation at break, and other mechanical properties were studied. At the same time the effect of the E20 content on the peel strength of the adhesive for several automobile interior decoration substrates such as rubber/wood, poly(vinyl chloride)/wood; leather/wood, sponge/wood was investigated. The experimental results show that when the epoxy resin E20 content was 8%, the modified polyurethane hybrid dispersions possess better properties and the adhesive made by the modified dispersions posses better adhesion for automobile interior decoration substrates. The stress-strain curve of the modified aqueous polyurethane hybrid dispersions films shows the modified aqueous cast films possess better rigidity and toughness.

UV-curable polyurethane acrylate–Ag/TiO 2 nanocomposites with superior UV light antibacterial activity

ABSTRACT Polyurethane acrylate (PUA)–Ag/TiO2 nanocomposites were synthesized through in situ polymerization. The well-dispersed Ag/TiO2 nanorods serve as photoinitiator. Meanwhile, the PUA–Ag/TiO2 nanocomposite films exhibit superior activity toward the photocatalytic degradation of Escherichia coli under UV light. The excellent UV curing and antibacterial activities can be ascribed to the synergistic effect of Ag and TiO2, which promotes the effective electron/hole separation and thus generates various reactive species. Thin films with these nanoparticles are more hydrophilic after UV illumination. And the antibacterial mechanism of the UV-curable PUA–Ag/TiO2 nanocomposites was proposed. GRAPHICAL ABSTRACT

Waterborne polyurethane-silanized CoFe2O4-acrylate magnetic pressure-sensitive adhesive

ABSTRACT A novel waterborne polyurethane-silanized CoFe2O-acrylate magnetic pressure-sensitive adhesive was prepared. With the increase of PU content, gel content, swelling capability, and SAFT increased, and fracture energy increased first, then decreased. The T-peeling strength increased from 8.93 to 19.07 N · m−1, tack force increased from No.3 to No.10, while shear resistance increased from 35 to 72 h, and then they decreased. Two empirical models: WA = 90.46 + 125.04[PU]-319.96[PU]2 and T = 9.09 + 96.07[PU]-235.11[PU]2, were obtained. With the increase of CoFe2O4 content, the saturation magnetization increased from 5.5 to 14.2 emu · g−1, and remanence increased from 1.7 to 3.7 emu · g−1, while coercivity decreased from 875 to 763 Oe. GRAPHICAL ABSTRACT

Modification of Chitosan-Fe3O4 microspheres with Isophorone diisocyanate and formation of polyurethane/mChitosan-Fe3O4 antimicrobial polymer

ABSTRACT Polyurethane/modified chitosan-Fe3O4 (PU/mCS-Fe3O4) nanocomposites were prepared by incorporating chitosan-Fe3O4 (CS-Fe3O4) into PU through chemical grafting using isophorone diisocyante (IPDI). The isocyanate group of IPDI was introduced on the surface of CS-Fe3O4 nanocomposites. The chemical functionalities of the CS-Fe3O4 and mCS-Fe3O4 were verified by Fourier-transform infrared and X-ray diffraction. The structure and properties were confirmed by scanning electron microscope, vibrating sample magnetometer, thermogravimetric analysis, atomic force microscope, and tensile testing. The experimental results indicate that thermal stability, tensile strength, and storage modulus of nanocomposites were improved with the increasing content of mCS-Fe3O4. Meanwhile, PU/mCS-Fe3O4 nanocomposites have less cytotoxicity and good antibacterial activities againstEscherichia coli and Staphylococcus aureus. GRAPHICAL ABSTRACT

Synthesis and properties of electrical conductive and antibacterial siloxane-modified carbon fiber–silver–acrylate nanocomposites

ABSTRACT First, silanized carbon fiber (SCF) was synthesized, then silanized carbon fiber–silver (SCF-S) was obtained. Finally, silanized carbon fiber–silver–acrylate (SCF-S-A) electrical conductive and antibacterial composites were prepared. The structures of CF, SCF, SCF-S, and SCF-S-A were characterized by X-ray photoelectron spectroscopy, FTIR, scanning electron microscopy, X-ray diffraction, Raman spectroscopy, and UV spectra. The electrical conductive and antibacterial properties of SCF-S-A nanocomposites were studied. The results showed that electrical conductive and antibacterial activity properties of SCF-S-A nanocomposites were improved. When the content of SCF-S was 50%, the conductivity of SCF-S-A nanocomposites was maximum. The SCF-S-A nanocomposites will have promising application in high-performance electrical conductive and antibacterial materials. GRAPHICAL ABSTRACT