Lifen Hao

Facile fabrication of superhydrophobic cotton fabric from stearyl methacrylate modified polysiloxane/silica nanocomposite

The stearyl methacrylate modified polysiloxane/nanocomposite was synthesized by graft copolymerization between stearyl methacrylate modified polysiloxane with pendent epoxy groups and amino-functionalized nano silica. Then it was utilized to fabricate the superhydrophobic cotton fabric by one-step method. The structures, chemical compositions, thermal properties, surface morphology and wettability were characterized by Fourier Transform Infrared Spectrum (FT-IR), X-ray photoelectron spectroscopy (XPS), Thermo-gravimetric analyzer (TGA), Scanning electron microscopy (SEM) and Static contact angle analyzer. Results showed that a hydrophobic polysiloxane film and many nano-scaled tubercles were coated on the surface of the treated cotton fabrics plus their inherent microscaled roughness, which were the reasons why cotton fabric changed from hydrophilicity to hydrophobicity. In addition, with increase of the amount of nanocomposite, hydrophobicity of the treated cotton fabric would be enhanced; water contact angle of this fabric could attain 157°, which was higher than 141.5° reached by the fabric treated with stearyl methacrylate modified polysiloxane. The superhydrophobic cotton fabric also possessed favorable washing durability. On the other hand, its air permeability, color and softness would not be influenced instead.

Synthesis of Self-crosslinking Fluorinated Polyacrylate Soap-free Latex and Its Waterproofing Application on Cotton Fabrics

Fluorinated polyacrylate latexes are preferably candidates for the textile water repellent finishes as a result of their special surface property and especially economical, low-toxic characteristics compared to fluorinated polyacrylate solutions. The benefits of soap-free latex prepared from reactive surfactants are now well known. We herein used a reactive emulsifier, ammonium allyloxtmethylate nonylphenol ethoxylates sulfate (DNS-86), to prepare novel self-crosslinking fluorinecontaining polyacrylate soap-free latex (FMBN) with core-shell structure by co-polymerization of dodecafluoroheptyl methacrylate (DFMA), methyl methacrylate (MMA), butyl acrylate (BA), and N-methylolamide (NMA), and then treated the cotton fabric with FMBN. Results showed that the as-prepared latex particles had the uniform spherical core-shell structure with an average diameter of 116 nm. FMBN could form a smooth resin film on the treated fabric/fiber surface under Field emission scanning electron microscopy (FESEM) observation, but some protuberances appeared on that surface from Atomic force microscopy (AFM) image. X-ray photoelectron spectroscopy (XPS) analysis indicated the fluoroalkyl groups tended to enrich at the film-air interface. Hydrophobicity of the FMBN treated fabric was superior to that of the fabrics treated by general emulsion and the non-crosslinking one. In addition, the above three latexes didn’t influence whiteness of the treated fabrics at all. However, they all, and in especial two self-crosslinking latexes would make the treated fabrics stiffer compared to non-crosslinking one.

Synthesis of cationic core-shell fluorine-containing polyacrylate soap-free latex and its application on cotton substrate

Fluorinated polyacrylate latexes are preferably potential materials for use in the textile finishing due to their special surface property and especially economical, low-toxic characteristics compared to fluorinated polyacrylate solutions. A novel cationic fluorine-containing polyacrylate soap-free latex (CFMBD) with core-shell structure was accordingly developed by co-polymerizing dodecafluoroheptyl methacrylate (DFMA), methyl methacrylate (MMA), butyl acrylate (BA), and dimethylaminoethyl methacrylate (DM) using a cationic reactive emulsifier, maleic acid double ester-octadecyl poly(ethyleneoxy)20 ether-ethylene trimethyl ammonium chloride (R303). Then CFMBD was utilized to treat the cotton fabric. Results showed that the as-prepared latex had due structure and its particles had uniform spherical core-shell structure with an average diameter of 125 nm. The core-shell CFMBD latex film thus had two Tg and its thermal property was improved due to the introduction of DFMA. CFMBD could form a smooth resin film on the treated fabric/fiber surface under FESEM observation. XPS analysis indicated the fluoroalkyl groups had the tendency to enrich at the film-air interface. Hydrophobicity of the CFMBD treated fabric was slightly superior to that of the fabric treated by general emulsion but their oleophobicity was identical. Contact angles of water and diiodomethane on the CFMBD treated fabric surface could attain 133.5 ° and 105.5 °, respectively. However, washing durability of the treated fabric by CFMBD showed improvement compared to the general emulsion. In addition, CFMBD didn’t influence whiteness of the treated fabric but would make it slightly stiff at high doses.

Synthesis, film morphology and performance of novel crosslinked polysiloxane with end-capped epoxy groups on cotton substrates

An epoxy group-terminated polyvinylmethylsiloxane (EPVMS) was firstly prepared via the cohydrolysis/condensation reaction of octamethylcyclotetrasiloxane (D4), 2,4,6,8-Tetramethyl-2,4,6,8-tetravinylcyclotetrasiloxane (D4V), and epoxy group-terminated polydimethylsiloxane (ETP) under a base catalyst. Then, the EPVMS was reacted with polymethylhydrosiloxane oligomer (PHMS) by hydrosilylation to develop novel crosslinked polysiloxane with end-capped epoxy groups (CLPS). The chemical structure and the thermal property of the as-prepared products were characterized by Fourier transform infrared spectroscopy (FT-IR), nuclear magnetic resonance spectra (1H/13C NMR) and thermogravimetric analysis (TGA). Finally, the CLPS was applied as the finishing agent to treat the cotton fabrics. The film morphology and the surface properties were examined with scanning electron microscopy (SEM), atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), contact angle measurements, and other instruments. FT-IR and NMR results confirmed the structure of the resultants. The crosslinked polysiloxane CLPS showed better thermal stability than the uncrosslinked polysiloxane EPVMS. The CLPS film on cotton fabric surface seemed to be smooth compared to the control by SEM. However, owing to the crosslinked structure, the CLPS film on silicon-wafer was inhomogeneous and had a few weak or strong peaks. At 5 nm data scale and in 2×2 μm2 scanning field, the root mean square roughness of CLPS film reached to 0.414 nm. XPS analysis further demonstrates that there was a CLPS film covered on the cotton surface. Hydrophobicity of the CLPS treated fabric was superior to that of the EPVMS treated one. Whiteness of the treated fabrics by CLPS and EPVMS did not change at all compared to the control. The softness of the two treated fabrics was both better than that of control and particularly the softness of the EPVMS treated fabrics was preferable. The CLPS treated fabric possessed good washing durability.

Synthesis Optimization of Novel Cross-Linked Polysiloxane with End-capped Epoxy Groups as Waterproofing Agent for Fabric

Novel cross-linked polysiloxane with end-capped epoxy groups as waterproofing agent for fabric was synthesized by hydrosilylation of polymethylhydrosiloxane and an epoxy groups-terminated polyvinylmethylsiloxane, which was previously prepared via anionic ring-opening polymerization of octamethylcyclotetrasiloxane, 2, 4, 6, 8-Tetramethyl-2, 4, 6, 8-tetravinylcyclotetrasiloxane, and epoxy group-terminated polydimethylsiloxane using tetramethylammonium hydroxide as a catalyst. Synthesis parameters were discussed in detail. Fourier transform infrared spectroscopy and nuclear magnetic resonance spectra confirmed structure of the resultants. X-ray photoelectron spectroscopy analysis further verifies that the cross-linked polysiloxane film was indeed covered on cotton surface. Thermal stability of those polymers was improved with augment of the cross-linking degree.

Synthesis and Properties of Cationic Fluorinated Polyacrylate Soap-Free Latex

Cationic fluorinated polyacrylate soap-free latex (CFMBD) was synthesized by semi-continuous seeded emulsion polymerization of dodecafluoroheptyl methacrylate (DFMA), methyl methacrylate (MMA), butyl acrylate (BA), and dimethylaminoethyl methacrylate (DM) with a novel cationic polymerizable emulsifier, maleic acid double ester-octadecyl poly(ethyleneoxy)20 ether-ethylene trimethyl ammonium chloride (R303), and 2,2′- azobis (2 - methylpropionamidine) dihydrochloride (VA-50) was utilized as the initiator. Effects of some factors, such as VA-50 amount, R303 amount and DFMA amount, on stability and average particle size of the CFMBD were discussed in detail, and the optimal polymerization condition was obtained. In addition, the emulsion and its film were characterized by Fourier transform infrared (FTIR) spectrometry, thermogravimetry analysis (TGA), contact angle goniometer, X-ray photoelectron spectroscopy (XPS), respectively. FTIR confirmed the structure of the CFMBD. With the increasing of DFMA amount, water absorption of the film decreased and water contact angle of the film increased. While the DFMA amount was more than 6 g in the recipe, the water contact angle (107.5°) and the water absorption (7.8 wt%) of the film showed no more changes. Meanwhile, thermal stability of the copolymer was greatly improved with the increasing of DFMA amount. XPS analysis indicated the fluoroalkyl groups had the tendency to enrich at the film-air interface.