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1.
    
Enzyme‐mediated in situ functionalization of cotton fibers was studied using laccase. Caffeic acid and morin were used as reactive phenolic substrates for laccase and further employed to the modification of fiber surfaces. Laccase‐mediated oxidation and polymerization reactions of caffeic acid were monitored by ultraviolet–visible spectroscopy. During the wetting process, initial cationization of fiber surfaces using poly(diallyldimethylammonium chloride) followed by enzymatic treatment with phenolic substrates resulted ineffective polymer grafting evidenced by high color stability. Changes of fiber surface properties by polymer grafting, such as morphology and hydrophilicity/hydrophobicity, were tested using scanning electron microscopy and gravimetric absorption tests. An acceptable level of color resistance to washing stress was obtained on caffeic acid treated samples, and a high level of rubbing resistance was obtained on samples treated with both caffeic acid and morin. Regarding the ultraviolet protection test, the cationized and enzymatically functionalized samples showed a very good protection grade (ultraviolet protection factor = 25). Finally, the antioxidant activity test of the modified fibers presented an improvement for radical scavenging potential due to the phenolic compounds incorporated to cotton fibers by laccase‐mediated catalysis. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 45801.  相似文献   

2.
    
In this work, chitosan hydrogel has been synthesized and used to impart pH‐sensitivity and antimicrobial finish to cotton fabric. In order to enhance the incorporation rate of hydrogel, anionic, and cationic activation of the textile surface was applied and then compared. The antibacterial activity of the fabric was then studied. The results revealed an enhancement of the antibacterial activities of the modified fabrics against Escherichia coli, Listeria monocytogene, and Staphylococcus aureus bacteria's. The capacity of material to respond to pH change was studied and confirmed using contact angle method. The anionic fabric treated with hydrogel showed a better pH‐responsiveness. Scanning electron microscopic testing results has also confirmed that the deposition of hydrogel was clearly better with the anionic activation. The characteristics of breathability of the fabrics were analyzed. The results show that the moisture management behavior of the finished materials is significantly better than the control one. Although the permeability to air has reduced by 10%, the permeability to water vapor remained practically unchanged. Furthermore, the effects of the antibacterial finishing on the physical properties of the cotton fabrics were also investigated. It was established that the functionalized samples have changed structure parameters, thickness, air permeability, tensile strength, and resistance to wrinkles. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46645.  相似文献   

3.
    
Polyacrylic acid (PAA) is one of the most exciting hydrophilic polymers for water control and conservation; however, it suffers from poor mechanical properties during the agricultural applications. For that purpose a series of PAA-based multiwalled carbon nanotubes (MWCNTs) membranes have synthesized via a grafting process of MWCNTs using chitosan (CS) polymer as a binder. The fabricated membranes have spectroscopically characterized by different techniques to confirm the composite structure. The MWCNTs content into the PAA membranes has played a pronounced effect on water absorptivity, swelling behavior, and mechanical properties. PAA membrane has showed a fourfold increase in yield-stress by the addition of 3 wt% PAA/CS/MWCNTs, while preserving a 91% of water absorptivity of PAA membrane. The soil applications of the PAA/CS/MWCNTs membranes have showed remarkable improvements in soil moisture content compared to the PAA membrane. This study provides a promising pathway for future field applications, especially in arid lands.  相似文献   

4.
    
Subbituminous coal from the powder river basin was extracted with N,N-dimethylformamide at atmospheric pressure to yield a solid extract that provided phenolic and carboxylic acid groups. The coal extract was employed as polyol in polyurethane (PU) synthesis. A solvent-free synthesis using 2,4-toluene diisocyanate (TDI) resulted in a porous PU solid. Reaction with TDI in solution resulted in a soluble PU that could be applied as adhesive or coating. Coatings were also prepared from coal extract solutions and commercial, polymeric isocyanates, providing excellent adhesion to aluminum. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48776.  相似文献   

5.
膨胀型防火涂料防火体系的研究   总被引：2，自引：0，他引：2  
以聚磷酸铵(APP)/三聚氰胺(MEL)/双季戊四醇(DPER)为防火体系,自交联硅丙乳液为基质树脂的膨胀型防火涂料为研究对象,研究双季戊四醇对防火涂料耐水性和炭化层结构的影响,并采用正交试验对防火体系的配比进行优化.  相似文献   

6.
    
Titania precipitation on cotton has been achieved using a commercially available antimicrobial polymer, Reputex 20. The cotton swatches precipitated with titania retain antimicrobial activity, and we have also shown the ability to encapsulate diisopropylfluorophosphatase (DFPase), an enzyme capable of breaking down organofluorophosphates. Cotton swatches are easily prepared and precipitation occurs at room temperature in aqueous solutions at neutral pH. Both the antimicrobial properties of Reputex 20 and the hydrolytic activity of the DFPase enzyme are retained after titania precipitation, generating a cotton material exhibiting multifunctional properties. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43199.  相似文献   

7.
    
Numerous techniques of preparation have been reported for the encapsulation of the core material, but the microemulsion technique is the most effective and commonly used for encapsulation. In this article, three microemulsification devices including ultrasonic stirrer, labo ratory reactor, and mechanical stirrer were used to produce the alginate nanocapsules containing peppermint oil. The effect of different parameters on surface morphology, mean particle size, and size distributions were investigated. The results indicated that the ultrasonic stirrer is the best device to make the nanocapsules containing essential oils prepared by microemulsion method, so that the size of nanocapsules prepared by ultrasonic stirrer was about 56 nm. Also, the results of GC‐MS, FTIR, and TGA show that quantities of the remaining compounds in nanocapsules prepared by ultrasonic stirrer are higher than other devices. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41904.  相似文献   

8.
    
Hollow-fiber (HF) membranes have the advantage of a higher packing density compared to flat-sheet and spiral-wound configurations. However, the low pressure tolerance of HF membranes limits their applications in nanofiltration (NF). In this study, reinforced thin-film composite (r-TFC) HF NF membranes were fabricated and evaluated in tests with water containing different salts and organic matter. Reinforced polysulfone ultrafiltration membranes were used as a support for a polyamide layer prepared from piperazine and trimesoyl chloride monomers. The interfacial polymerization conditions were optimized via selection of the trimesoyl chloride reaction time that gave the highest membrane performance. A specific permeate flux of 5.1 L m–2 h–1 bar–1, an MgSO4 rejection of 69%, and an NaCl rejection of 26% at a transmembrane pressure of 6 bars were obtained with the optimized r-TFC membranes. Performance studies with water characterized by synthetic solution demonstrated removals of the total organic carbon, ultraviolet absorbance at 254 nm, and turbidity in excess of 65, 80, and 90%, respectively. The results of this study illustrate the feasibility of manufacturing r-TFC HFs and using them in water-treatment applications. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 48001.  相似文献   

9.
    
Superhydrophobic coating was developed on cotton fabric in this article using a dodecafluoroheptyl‐containing polyacrylate (DFPA) and nanosilica. Film morphology of DFPA on cotton fibers/fabrics and chemical compositions of the treated cotton fabric were investigated using scanning electron microscopy (SEM), atomic force microscopy (AFM), and X‐ray photoelectron spectroscopy (XPS), respectively. DFPA could form a relatively even film on the cotton fabric/fiber under SEM observation; however, it presented a rough and microphase‐separated pattern under AFM observation. There were many mountain‐like protuberances. The height of the protuberances and the root mean square roughness (Rms) of the film reached about 20–50 nm and 12.511 nm in 2 × 2‐μm2 scanning field (as the scale data was 100 nm). XPS analysis indicated that the perfluoroalkyl groups had the tendency to enrich at the film–air interface. DFPA could make the treated cotton fabric with a water contact angle (WCA) at about 138.5°. Cotton fabric was previously roughened using a 1 wt % silica sol with an average particle size of 20–30 nm and then finished by DFPA; hydrophobicity of the resultant cotton fabric was strongly improved, and WCA could reach 153.6°. The color of this superhydrophobic fabric would not be influenced, but its softness decreased compared to untreated fabric. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013  相似文献   

10.
    
Poly(methylmethacrylate)(PMMA)/oxymethylene‐linked polyoxyethylene multi‐block polymer(Om‐POEn, where n represents number of unit  CH2CH2O ) blend based composite electrolyte films containing different lithium salt concentration and nanofillers' content are prepared using solvent evaporation technique. The interaction of polymer–salt complex has been confirmed using FTIR spectral studies. The figuration of CPE was studied by XRD. Ionic conductivity and thermal behavior of the CPEs were studied with various salt concentrations, temperature, and nanofillers' content. The surface structure of the CPE is also investigated using scanning electron microscopy. The high room temperature ionic conductivity, transmittivity in the visible region, and thermal stability make these CPEs potential candidates as solid‐like electrolytes for electrochemical devices. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007  相似文献   

11.
    
Composite membranes of sulfonated poly (phthalazinone ether ketone)s (SPPEK)s and Zirconium hy drogen phosphate (ZrP) or 12‐phosphotungstic acid (PWA) were prepared by direct blending method. The physicochemical properties of these composite membranes were studied through Fourier transform infrared attenuated total reflection (FTIR‐ATR) spectroscopy, field‐emission scan ning electron microscope (FSEM), X‐ray diffraction (XRD) and thermogravimetry analysis (TGA). The SPPEK/PWA composite membranes showed better properties, whose highest proton conductivity could reach 0.17 S/cm at 80°C under 100% relative humidity (R.H.). © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 3972–3977, 2006  相似文献   

12.
    
The discussion focuses on the application of a Payne cell to the measurement of diffusion and solubility coefficients in polymer/solvent systems. Payne cells have, thus far, been used exclusively to measure steady-state permeation rates of solvents. An analytical model has been developed to describe transient gravimetric sorption and desorption measurements performed with a Payne cell. The model has been validated by a complementary numerical simulation and has been applied to evaluate diffusion and solubility coefficients in two different toluene-silicone rubber systems. The data measured using the Payne cell are found to compare very well with diffusion coefficient and isotherm data measured by traditional gravimetric sorption experiments.  相似文献   

13.
    
In this paper, poly(lithium acrylate‐co‐butyl acrylate) [P(AALi‐co‐BA)] was synthesized, and a P(AALi‐co‐BA)‐coated polypropylene (PP) separator was prepared by a simple dip‐coating process. In contrast to the conventional thick, dense gel polymer coating layer, a thin P(AALi‐co‐BA) layer was formed on the PP separator, which had less influence on the pore structure of the original PP separator and was beneficial for the migration of lithium ions through the separator. Furthermore, the AALi units in the copolymer could improve the wettability of the separator, while the BA units provided the separator with strong adhesion to the electrodes. As expected, the modified separators showed good wettability, high ionic conductivity, and excellent interface stability. In addition, the cycle stability and rate performance were also improved significantly. This facile, affordable, and effective method has great application potential for the modification of polyolefin‐based separators. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46423.  相似文献   

14.
    
In this study, it was aimed to develop electrically and thermal conductive textiles surfaces. Pretreated polyester fabrics were coated with nano graphene powders at different concentration rates (50, 100, and 200 g/kg) by knife over roll technique. Electrical resistivity, thermal conductivity, thickness and mass per unit area measurements, bending rigidity, and abrasion resistance tests of coated fabrics were performed. Surface resistivity measurements of coated fabrics were made according to ASTM D 257 standard with Keithley 8009 Resistivity Test Fixture. Surface electrical resistivity values of coated fabrics decreased with increasing concentration rates. Of note, 2.53 × 104 Ω/sq surface resistivity value was obtained at 200 g/kg graphene concentration rate. Thermal conductivity measurements of coated fabrics were made according to JIS R 2618 standard with Quick Thermal Conductivity Meter (QTM-710). Thermal conductivity property of fabrics improved depending on graphene concentration. The highest thermal conductivity value (0.4243 W/mK) was obtained at 200 g/kg graphene concentration rate. One of the most important results of the study was that a maximum weight loss of 0.40% was observed in the abrasion resistance test even after 100 000 cycles. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 48024.  相似文献   

15.
    
A three‐layer functional coating was prepared through layer‐by‐layer (LbL) assembly and a sol–gel process. The multilayered coating was composed of a phytic acid (PA) coating dipped between two layers of flexible polysiloxane coatings and was deposited on the polyester fabric by LbL assembly. Flammability tests indicated that the multilayer coating prevented droplet generation during combustion. The PA also absorbed the reactive free radicals to reduce the flame‐burning rate. After being soaked for only 20 min in PA solution, the fabric exhibited self‐extinguishing properties and antidroplet effect during the vertical flame test, while cone calorimetry confirmed that the coated fabric exhibited a 65% decrease in the peak heat release rate and reduced the total amount of smoke released by 72%. After washing the coated fabric 45 times, there was no significant decrease in the phosphorus content and the limiting oxygen index of coated fabrics. Thus, the coating synthesized in this study is an effective method of constructing durable, functional coatings on the surface of fabrics. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46414.  相似文献   

16.
    
In this work, cationic waterborne polyurethane/acrylate (WPUA) was synthesized for water repellent in cotton fabrics to replace fluorine-containing finishing agents with the concerns of ecosystems and human health. First, the tertiary amines monomers, N-methyl diethanolamine, 3-dimethylamine-1, 2-propylene glycol, N,N′-bis (2-hydroxyethyl)piperazine, were used as chain extenders to prepare waterborne polyurethane, respectively. Long-chain octadecyl acrylate monomers were then grafted to the waterborne polyurethane by a self-emulsifying method. The stable WPUA suspensions of positively charged latexes were obtained and could be finished on cotton fabrics via a simple pad-curing process. The coated cotton fabrics were capable of repelling common liquids without any penetration, and the contact angles of the treated cotton fabrics could reach 150°. The WPUA latex films also exhibited good tensile mechanical properties and thermal dimensional stability. The cotton fabric coated with the WPUA showed good laundering durability, and its static water contact angle was still maintained at 142° even after 50 times washing. This work not only highlights the structural design and preparation but also provides a feasible strategy for fluorine-free water repellency in cotton fabrics, which has great potential application prospects for a variety of fields.  相似文献   

17.
    
Tuberose‐fragrance (TF) loaded polybutylcyanoacrylate nanoparticles were successfully prepared via emulsion polymerization. The nanotuberose fragrance (Nano‐TF) was directly impregnated into the cotton fabrics as an aromatic reagent. Dynamic light scattering and transmission electron microscopy showed that the average size of the spherical Nano‐TF was 202.4 nm. Fourier transform infrared spectroscopy demonstrated that TF was encapsulated into the BCA nanoparticles and that the Nano‐TF was in existence in the cotton fabrics. Thermogravimetric analysis showed that the loading TF content of the Nano‐TF was 50.9% and that 10.02% Nano‐TF had been impregnated into the fabrics. A lot of Nano‐TF was adhered onto the surface of the cotton fabrics after 50 washings, as shown by scanning electron microscopy and gas chromatography/hydrogen flame ionization detection (GC–FID). In addition, GC–FID demonstrated that most aroma compounds of the cotton fabrics impregnated with Nano‐TF only lost less than 20% of their aroma after 60 days of deposition and around 75% of their aroma after 6 h of deposition at 120°C, so they showed better sustained‐release properties than those with TF. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41678.  相似文献   

18.
    
The use of coatings based on alkoxysilanes is one of the most effective ways to control the release of cytotoxic ions by metal implants. To improve the success rate of titanium–aluminum–vanadium implants, in this study, we evaluated the physicochemical, morphological, mechanical, and electrochemical behavior of hybrid coatings based on alkoxysilanes applied on the alloy. The coatings were prepared with the precursors 3‐(trimethoxysilyl propyl)methacrylate and tetraethoxysilane alkoxides by the sol–gel method. The curing of the coatings was evaluated at different temperatures (90, 180, and 300 °C) for 1 h. We carried out the pretreatment of the alloy by polishing and attacking it with sodium hydroxide. The results indicate that the temperature of 90 °C was effective for solvent evaporation and complete crosslinking of the film, and the alkaline pretreatment allowed the formation of a film with better anticorrosive performance; this indicated that the presence of hydroxyl groups on the surface improved the coating adhesion. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45470.  相似文献   

19.
    
In this article, we report on an experimental investigation of the thermal insulation and moisture vapor resistance of a thermal insulation assembly consisting of polyester battings and metal‐coated thin nonwoven interlayers. Because of the blocking of radiation by the coated metal nanoparticles, the thermal radiative conductivity of the interlayer decreased from 0.0249 to 0.0194 W/m K after coating. We found that the thermal insulation of the fibrous assembly could be greatly improved without any significant effect on the moisture transfer through the incorporation of metal‐coated interlayers between the fibrous battings in appropriate patterns. The thermal resistance of the assembly increased gradually with increasing number of incorporated interlayers until it reached a plateau. The presence of more metal‐coated interlayers closer to the hot (heat‐source) side was beneficial to higher thermal insulation. The moisture vapor resistance of the assembly showed no significant changes with increasing number of interlayers. The incorporation of three interlayers showed the best thermal insulation properties with little effect on the moisture transmission. This kind of thermal insulation assembly will have significant advantages in cold‐protective clothing because of its high insulation properties and breathability. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40205.  相似文献   

20.
    
This article reports a facile one‐step methodology to increase fire resistance properties of cotton fabric. The flame‐retardant coating for cotton fabric was synthesized with methyltriethoxysilane and organophosphates (M102B) through an ultrasound irradiation process. The coating structure and surface morphology of uncoated and coated fabrics were investigated by Fourier transform infrared spectroscopy and scanning electron microscope, respectively. The flame‐retardant properties, bending modulus, air permeability and thermal stability were studied by vertical burning test, cantilever method, air permeability test and thermogravimetric analysis (TGA). As a result, the cotton fabric coated with 29.2% (mass increased) of flame‐retardant coating was able to balance the flame retardant property and wearing comfort of the fabrics. The TGA results showed that the residue char of cotton was greatly enhanced after treatment with the coating, which has a high char forming effect on cellulose during testing. Furthermore, flame‐retardant property of coated fabrics did not change significantly after 10 washing cycles. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45114.  相似文献   

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