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 T _g 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 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 core-shell fluorinated acrylate copolymers and its application as finishing agent for textile

Core-shell fluorinated acrylate copolymers emulsion was thus synthesized via the core-shell emulsion polymerization with the fluorinated monomers and acrylic monomers as the main raw materials and its properties were studied. PFMA, the fluorinated acrylate monomers, was synthesized by the esterification of perfluorooctanoyl chloride (PFOC) and hydroxypropyl methacrylate (HPMA). Then the core-shell fluorinated acrylate copolymers emulsion with a poly(MMA/BA/St) core and a poly(PFMA/MMA/BA) shell was synthesized via a starved semi-continuous core-shell emulsion polymerization method by using KPS and sodium bicarbonate as the initiator/buffer system and SDS/Twain 80 as the commixture emulsifier. Lastly, the synthesized copolymers was applied as textile finishing agent for cotton textile. The results of FT-IR and NMR indicated that PFMA had been synthesized as expected and effectively combined in the emulsion copolymerization. The GPC, zeta potential, TEM and DSC showed that the particles had uniform spherical core-shell structure with a diameter of 65-150 nm, and the distribution and emulsion stability was satisfactory. As XPS, FESEM and AFM shown, a hydrophobic structure which was similar to the structure of the lotus leaf were formed and the surface hydrophobicity of the films can be improved. Based on the analysis of DSC, thermal stabilities of the films were enhanced with the increase of fluorine content. Besides, FESEM of textiles showed that the surface of treated textiles were smooth and the edges were clear and visible, indicating significant improvement of the performance on water and oil repellent.     

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 and Characterization of Waterborne Polyurethane Modified by Acrylate/nano-ZnO for Dyeing of Cotton Fabrics

Waterborne polyurethane modified by acrylate/nano-ZnO (PUA/ZnO) was synthesized and used to improve the wet rubbing fastness of reactive dyed cotton fabric. The reaction conditions were optimized and the products were characterized by FT-IR, TG, DSC, SEM, and particle size distribution. The dyed cotton fabrics were finished with PUA/ZnO emulsion and the rubbing fastness, ultraviolet resistant property, and wearability of treated fabrics were measured. The wet rubbing fastness of treated fabrics was increased by about 0.5–1 rate to achieve 3–4 rate, and the ultraviolet protection factor (UPF) achieved 50+ level. The whiteness, air permeability, and elongation at break of treated fabric were not decreased significantly. SEM showed that the smooth and reticular coating on the surface of treated fabric reduced the mechanical friction force between dyed fabric and rubbing cloth, and thus improved the rubbing fastness. The decomposition temperature of finished fabric was increased by 50–80 °C.     

地被银桦试管苗增殖培养研究

地被银桦是杂交品种，无性繁殖对保持地被银桦的品种特性至关重要。本研究以组织培养为繁殖方法，从激素的浓度、种类、大量元素及糖等方面对地被银桦的增殖培养进行了系统的研究。结果表明，6-BA的浓度对增殖苗的高度有显著影响，6-BA和IBA对试管苗的玻璃化比例均有显著影响，NH4NO3和KH2PO4的浓度也显著影响增殖苗的高度。最适增殖培养基配方为：改良MS培养基(NH4NO3 412.5 mg/L ，KH2PO4 85 mg/L)＋6-BA 0.3 mg/L＋IBA 0.1 mg/L＋糖35 g/L。     

Reducing silk fibrillation through MMA graft method

Silk fibrillation, one major weakness of silk fibers, can lead to undesirable fabric appearance. In this research, an effective method for reducing the fibrillation of silk fibers through the graft copolymerization with methyl methacrylate (MMA) has been developed. The major copolymerization factors such as the initiator concentration, MMA monomer concentration, reaction time and temperature were investigated. An AATCC Crockmeter was used to rub the fabric to simulate the abrasion in production to generate the fibrillation. The microscope observation and the evaluation of fibrillation index (FI) were applied to assess the degree of fibrillation of silk fibers. The optimum graft copolymerization factors were obtained. Instrumental analyses, such as FTIR, TG and SEM, proved that the silk fabric had been successfully grafted with MMA monomers. The fibrillation of the grafted silk fibers was considerably reduced since the coated PMMA can protect the silk fiber. In addition, the physical properties such as the crease recovery, breaking strength, and the breaking length of the grafted silk fabrics were also improved.     

Preparation and flammability properties of hybrid materials containing phosphorous compounds via sol-gel process

Organic-inorganic hybrid coatings containing phosphoric acid (PA) bonded to the organic-inorganic network were prepared from tetraethoxysilane (TEOS) using a sol-gel process. The effect of sol-gel phosphate-based flame retardant coating on polyacrylonitrile fabric properties (flammability, stiffness, and strength) was investigated. Sample characterization of the coated samples were investigated using differential thermal/thermogravimetric analysis (DTA/TGA), Fourier transform infrared spectroscopy (FTIR), X-ray diffractometer (XRD), and scanning electron microscopy (SEM). The results showed that hybrid coating on the polyacrylonitrile fabrics influenced fabric stiffness, strength, and flammability. And also, flammability of the coated samples after washing cycles was investigated, and the flame retardancy properties of the samples after 10 repeated washings were not completely lost.     

Antibacterial Bombyx Mori silk fabric modified with reactive chitosan quaternary ammonium salt and its laundering durability

A new fiber-reactive chitosan derivative was synthesized in two steps from a chitosan of low molecular weight. First, a water-soluble chitosan derivative, N-[(2-hydroxy-3-trimethylammonium)propyl] chitosan chloride (short for HTCC), was prepared by reacting chitosan with 2,3-epoxypropyltrimethylammonium chloride. Second, HTCC was further modified by reacting with N-(hydroxymethyl)-acrylamide to prepare a fiber-reactive chitosan derivative, O-methyl acrylamide quaternary ammonium salt of chitosan (short for NMA-HTCC), which can form covalent bonds with silk fiber under alkaline conditions. The chemical structure of NMA-HTCC was characterized by Fourier transform infrared spectrum (FTIR) and nuclear magnetic resonance (NMR). The substitution degree of HTCC and the double-bond content of NMA-HTCC were tested. Then NMA-HTCC was used for antibacterial finishing of Bombyx Mori silk fabric. The results showed that silk fabric treated with NMA-HTCC had a significantly improved antibacterial activity to Staphylococcus aureus and Escherichia coli, and the antibacterial activity of silk fabric finished by NMA-HTCC was much better than that finished by chitosan and HTCC. Bombyx Mori silk fabric modified with NMA-HTCC demonstrated excellent durable antibacterial activity, even after 50 repeated launderings, the bacterial reduction rate of silk fabric maintained over 95 %.     

Water repellency and warmth retention finishes for polyester fabrics based on hybrid materials comprising zirconia,silica, and thiazole dyes prepared via sol-gel synthesis

A series of hybrid materials composed of zirconia, silica, and thiazole dyes were synthesized from zirconium npropoxide (ZNP) and tetraethoxysilane (TEOS) using heteroaryl 2-amino-thiazole azo dyes, and prepared via the sol-gel process. The heterocyclic 2-amino-thiazole azo dyes underwent a hydrolysis-condensation reaction with an appropriate proportion of ZNP under a catalyst, using a constant ratio of vinyltriethoxysilane (VTES) and TEOS. The structures of these hybrid materials composed of zirconia/silica/thiazole dyes were characterized using Fourier transform infrared (FT-IR) analysis. The surface morphologies of the polyethylene terephthalate (PET) fabrics were evaluated using scanning electron microscopy (SEM). The SEM images demonstrated the uniform dyeing of the PET fabrics, which confirmed the reaction of the hybrid materials with the PET fabrics. The water contact angle, washing fastness, color uniformity, and warmth retention of the PET fabrics dyed with the hybrid materials composed of the zirconia/silica/thiazole dyes were evaluated. The evaluation results indicated that these fabrics offered enhanced warmth retention properties and good water repellency.     

Improving wrinkle resistance of cotton fabric by montmorillonite

Cotton fabric was treated with montmorillonite (MMT) so as to evaluate its effectiveness on improving its wrinkle resistance. The MMT in emulsion form was applied to cotton fabric by padding and finally the wrinkle resistance of the MMT-treated cotton fabric was improved. Furthermore, instrumental methods were used for studying the presence of MMT particles on the cotton fabric surface. It was noted that nano-scale MMT particles adhered on the fiber surface and the particle size played an important role in influencing the wrinkle resistance of the cotton fabric. The experimental results are discussed thoroughly in this paper.     

Modification of polyethylene-polypropylene fibers by emulsion and solvent radiation grafting systems for boron removal

Preparation of boron-selective adsorbent was carried out by radiation induced grafting of glycidyl methacrylate (GMA) onto polyethylene-coated polypropylene (PE-PP) nonwoven fabric in emulsion or solvent medium followed by immobilization of N-methyl-D-glucamine (NMDG). Adsorbent precursors with 180 % degree of grafting (DG) were obtained by applying reaction parameters comprising 20 kGy dose, 5 % monomer concentration and 1 h reaction time in emulsion compared to 30 kGy, 10 % and 3 h in solvent medium. A glucamine density of 2.2 mmol/g could be imparted to the obtained adsorbents. The emulsion-mediated grafting was found more efficient and economical for preparation of boron chelating adsorbents.     

Size-controlled nanoparticles of poly(acrylonitrile-<Emphasis Type="Italic">co</Emphasis>-methyl methacrylate) for moisture-absorbing heat release applications

Hydrophilic and water-insoluble poly(acrylonitrile-co-methyl methacrylate) [P(AN-co-MMA)] nanoparticles were prepared to investigate their moisture-absorbing heat release effect. The nanoparticle size was controlled by varying the composition of AN and MMA. First, P(AN-co-MMA) nanoparticles were synthesized by emulsion polymerization, followed by cross-linking with hydrazine for water insolubility. Secondly, the hydrazine-cross-linked P(AN-co-MMA) nanoparticles were hydrolyzed in an aqueous NaOH solution to form hydrophilic groups. The hydrolyzed and cross-linked P(AN-co-MMA) [hc-P(AN-co-MMA)] nanoparticles had a more uniform and smaller particle size with increasing MMA content compared to the PAN nanoparticles, this is due to decreasing polar nitrile groups in the P(AN-co-MMA) with MMA content. A nanoparticle size less than 45 nm was obtained for P(AN-co-MMA) with a 20 mol% MMA content. The hc-P(AN-co-MMA) nanoparticles showed a temperature rise maximum of up to 12.9 °C in the moisture-absorbing heat release test. In addition, when the nanoparticles with 20 mol % MMA content were coated on cotton fabrics, the temperature of the fabrics increased by up to 7.8 °C at 90 % relative humidity. This demonstrates that the nanoparticles can be applied as a potential moisture-absorbing heat release material.     

Woven Kenaf/Kevlar Hybrid Yarn as potential fiber reinforced for anti-ballistic composite material

Woven Kenaf/Kevlar Hybrid Yarn is the combination of natural and synthetic fibers in the form of thread or yarn. The yarn is weaved to form a fabric type of fiber reinforced material. Then, the fabric is fabricated with epoxy as the resin to form a hybrid composite. For composite fabrication, woven fabric Kenaf/Kevlar hybrid yarn composite was prepared with vacuum bagging hand lay-up method. Woven fabric Kenaf/Kevlar hybrid yarn composite was fabricated with total fiber content of 40 % and 60 % of Epoxy as the matrix. The fiber ratios of Kenaf/Kevlar hybrid yarn were varied in weight fraction of 30/70, 50/50 and 70/30 respectively. The composites of woven fabric Kenaf/Epoxy and woven fabric Kevlar/Epoxy were also fabricated for comparison. The mechanical properties of five (5) samples composites were tested accordingly. Result has shown that of value of strength and modulus woven fabric Kenaf/Kevlar Hybrid Yarn composite was increased when the Kevlar fiber content increased. Therefore, among the hybrid composite samples result showed the woven fabric Kenaf/Kevlar Hybrid Yarn composites with the composition of 30/70 ratio has exhibited the highest energy absorption with 148.8 J which 28 % lower than Kevlar 100 % sample. The finding indicated there is a potential combination of natural fiber with synthetic fiber that can be fabricated as the composite material for the application of high performance product.     

Film morphology of supramolecule CPES/ASO and its performance on cotton substrates

The supramolecule CPES/ASO was self-assembled from carboxylated polyether-block-polydimethylsiloxane (CPES) and N-β-aminoethyl-γ-aminopropyl polysiloxane (ASO) in ethyl acetate solution. The film morphology and performance of CPES/ASO on cotton substrates were investigated by field emission scanning electron microscope (FESEM), atomic force microscope (AFM), X-ray photoelectron microscope (XPS), and so on. The results indicated that a polysiloxane resin film was coated on the treated fiber surface and able to decrease the root mean square roughness (R _q ) of the treated fiber conspicuously. Morphology of higher peaks circled by many smaller peaks was observed on the film surface, which was partly similar to that of CPES/ASO on the silicon wafer. Besides, when the mass ratio of CPES to ASO was 2:1, the fabric treated by CPES/ASO showed the best softness and had a comfortable oily tactile.     

Preparation of SAN/silicate nanocomposites using PMMA as a compatibilizer

Polymer/silicate nanocomposites were prepared via two-step manufacturing process: a master batch preparation and then mixing with matrix polymer. A hybrid of PMMA and Na-MMT with exfoliated structure was first prepared by emulsion polymerization of MMA in the presence of Na-MMT. For the case that SAN24, miscible with PMMA, is used as matrix, we could prepare a nanocomposite with exfoliated structure. However, SAN31 nanocomposite shows the aggregation and/or reordering of the silicate layers due to the immiscibility between SAN31 and PMMA.     

Bioinspired Fabric with Superhydrophilicity and Superoleophobicity for Efficient Oil/Water Separation

The cotton fabric was modified with dopamine methacrylamide (DMA) based on mussel-inspired reaction and polymerized with zwitterionic sulfobetaine methacrylate (SBMA) through free radical polymerization reaction. The poly(DMA-SBMA) contained not only key chemical constituents of dopamine hydrochloride, which strongly adsorbed to fabric substrates, but also hydrophilic groups, providing a hydrophilic surface for fabric due to its strong interaction with water via electrostatic interactions. The chemical structure, surface topography, and surface wettability of the fabric were characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and contact angle experiments, respectively. The results showed that the water contact angle (WCA) of the treated fabric was ~0 °, whereas the underwater oil contact angle (OCA) was ~161 °, as compared to ~25 ° for the control one. It is expected that as-prepared fabrics could be applied in oil/water separation due to such special superhydrophilicity and superoleophobicity.     

Preparation and property of TiO2/SiO2 multilayer film on the fabric by sol-gel process

The high light reflection of multilayer TiO₂/SiO₂ film was prepared on the fabric by the sol-gel process. The size of titania and silica particles in hydrosol was analyzed by Nanosizer, and the morphology of TiO₂/SiO₂ multilayer film on the fabric was characterized by SEM. The reflection spectra of the samples were tested accordingly, and it showed that the reflection of the fabric coated by multilayer film was higher than that of the monolayer film. Moreover, the reflection increased with the increase of layer number. For sunlight fastness testing, the fabric color changed less with the increase of layer number, which showed the multilayer film on the fabric can improve the light resistance of the fabric. The mechanical property, the bending property and air permeability testing results showed that there was little change for the coated fabric compared with the original fabric.     

Synthesis of silver nanoparticles with sericin and functional finishing to cotton fabrics

This research presents a novel strategy to fabricate multi-functional cotton textiles. In this study, silver nanoparticles-sericin (Ag NPS-sericin) hybrid colloid has been prepared using sericin as reducing agent and dispersing agent. Cotton fabrics was oxidized selectively with sodium periodate (NaIO₄) to generate oxidized cotton fabrics, and which has then been finished using Ag NPS-sericin hybrid colloid prepared to obtain multi-functional cotton textiles. The finished cotton fabric not only possessed excellent antibacterial activity, but also it was modified functionally by sericin protein, which endowed antibacterial cotton fabrics relatively smooth surface and good wear ability. Fourier transform infrared spectrogram confirmed that sericin protein was grafted onto cellulose fibers. Ag NPs were characterized by UV-Vis spectroscopy, transmission electron microscope (TEM) and X-ray powder diffraction (XRD). The results of SEM, X-ray photoelectron spectroscopy (XPS) and EDS confirmed that silver nanoparticles and sericin been loaded successfully on the surface of cotton fabrics. The antibacterial experiments showed bacterial reduction rates of S.aureus and E.coli were able to reach above 99 %. After washing 20 times, it showed still good antibacterial activity at over 95 % against S.aureus and E.coli.     

Light transmission and the fine structure of poly(methyl methacrylate) nanofibers and films

In this paper, the structure and optical properties of poly(methyl methacrylate) (PMMA) nanofibers and films were investigated. Differential scanning calorimetery (DSC) and Wide-Angle X-ray scattering (WAXS) results confirmed the amorphous structure of both nanofibers and films. Low angle X-ray diffraction (LA-XRD) revealed the presence of voids and/or particles with the spacing of 128.4 Å within the nanofibers. From the Porod plots, a three-dimensional surface fractal for the nanofibers and a mass fractal structure for the films were derived. By the interpretation of Small Angle X-ray scattering (SAXS), the shape and size of the particles in the samples were assessed. It was concluded that the particles shape within the nanofibers and the films were globular, with the radius of gyration of 8.5 nm for the nanofibers and 16.5 nm for the films. The nanofiber mat showed less light transparency when compared with the film. This phenomenon could be attributed to the difference in the physical shape, as well as scattering of the light by the voids or particles within the nanofibers.