Antimicrobial N‐halamine coatings synthesized via vapor‐phase assisted polymerization

An N‐halamine monomer, 3‐allyl‐5,5‐dimethylhydantoin (ADMH), was synthesized by a Gabriel reaction of 5,5‐dimethylhydantoin and 3‐bromopropene. Antimicrobial coatings of poly[1‐(4,4‐dimethyl‐2,5‐dioxoimidazolidin‐1‐methyl)ethylene] were prepared on plasma‐treated PET fabrics via a vapor‐phase assisted polymerization (VAP) process using gasified ADMH as monomer. The coatings endow the PET fabrics with an antimicrobial efficiency greater than 80% for both Escherichia coli and Staphylococcus aureus after chlorination of the N‐halamine polymer with dilute bleach solution. The obtained antimicrobial effect has remarkable durability that can bear over 30 times of stringent laundering tests. Compared with other antimicrobial finishing methods, the VAP methodology offers great advantages in needless of organic solvents and small consumption of monomer. It has potential applications in a wide variety of fields such as hygienic clothing, underwear, socks, and medical textiles. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41824.     

Cotton‐fabric‐grafted poly(N‐isopropyl acrylamide) initiated by ammonium peroxydisulfate

In this article, we report that thermoresponsive poly(N‐isopropyl acrylamide) (PNIPAAm) was successfully grafted onto a cotton fabric (CF) surface by free‐radical solution grafting polymerization; we obtained a thermoresponsive CF‐grafted PNIPAAm. This reaction system only contained four constituents: the monomer, solvent, initiator, and CFs. Ammonium peroxydisulfate was chosen as the initiator, and water was chosen as the solvent. A series of initiator concentrations and grafting polymerization temperatures were used in the experiments, and their effects on the grafting ratio (G) were also studied. Also, the effects of the G of CF‐g‐PNIPAAm on their corresponding thermoresponses was studied further. The structure of CF‐g‐PNIPAAm was characterized by Fourier transform infrared spectroscopy–attenuated total reflectance analysis and scanning electron microscopy analysis. The G of CF‐g‐PNIPAAm was measured by a gravimetric method. The thermoresponse of CF‐g‐PNIPAAm was characterized by modulated differential scanning calorimetry, water contact angle measurements, and wetting time measurements. The experiments manifested the following results: (1) the initiator concentration and grafting polymerization temperature both influenced G, (2) the grafted PNIPAAm covered the CF surface, (3) the CF‐g‐PNIPAAm showed thermoresponsive hydrophilicity/hydrophobicity, and (4) a relationship existed between the thermoresponse of CF‐g‐PNIPAAm and the corresponding G. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 41193.     

Electro‐conductive cotton fabric prepared by electron beam induced graft polymerization and electroless deposition technology

Cotton fabric has been made electro‐conductive by electroless deposition of silver from its salt solution. Preparation process involved radical graft polymerization of glycidyl methacrylate monomer on plain woven cotton fabric using 10 kGy dose of electron beam irradiation, and then hydrazination of the epoxy ring of the monomer to introduce reducing agents into the fibre chemical structure. These reducing agents are sites for metal particle deposition. The chemical modifications were characterized by infrared spectroscopic studies. From X‐ray diffraction pattern analysis, the average size of these deposited silver metallic particles is 41 nm. These are observed as heterogeneous deposition on the fibre surface in scanning electron images. From thermogravimetric analysis, around 7.5% of the metal plated fabric weight is silver. The deposited silver nanoparticles make a conductive pathway through contact network, and this network brings a drop in average value of surface resistivity of the cotton fabric from 10⁹ Ω/sq to 3.63 Ω/sq for the metallised fabric. Such prepared electro‐conductive fabric showed very good wash durability of electrical conductivity up to 15 washing cycles when carried out as per ISO‐105‐C10:2006 (E) test no. A (1) standard, indicating firm adherence of silver nanoparticles to the fabric surface. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44576.     

Wear‐resistant cotton fabrics modified by PU coatings prepared via mist polymerization

Cotton fabric was successfully modified using a simple mist polymerization with polyurethane (PU) prepolymer and ethylene glycol as the monomers. Scanning electron microscope showed the presence of a very thin polymer coating on the cotton fiber surface. Martindale abrasion tests revealed that the thin PU coating imparted to the cotton fabric a doubled wearing durability compared with the original fabric. Additional experiments demonstrated that the mist polymerization has little impact on the desired cotton properties such as water absorptivity, vapor transmissibility, mechanical property, and flexibility. Considering the excellent balance between the enhanced abrasion resistance and the cotton natures, this surface modification methodology has potential to fabricate wearing durable textiles. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43024.     

Preparation of hybrid composite microspheres containing nanosilicon via microsuspension polymerization

Hybrid composite microspheres with nano‐Si as the core and poly(styrene‐co‐acrylonitrile) as a shell are successfully prepared by a two‐step polymerization technique, which includes dispersion polymerization of styrene and 3‐methacryloxypropyl trimethoxysilane in ethanol for surface modification of nano‐Si followed by microsuspension polymerization of styrene and acrylonitrile in an aqueous phase for encapsulating nano‐Si into an SAN copolymer matrix. The structure and surface properties of modified nano‐Si are investigated by Fourier transform infrared spectroscopy (FTIR) and contact angle. The hybrid composite microspheres are systematically characterized by energy dispersive spectroscopy, thermogravimetric analysis, and transmission electron microscopy (TEM). According to the FTIR spectra and the contact angle experiments, it was determined that a hydrophobic polymer layer was formed on the surface of nano‐Si. TEM showed that nano‐Si was homogeneously dispersed in SAN particles when the loading capacity of nano‐Si in the hybrid composite microspheres was less than 20 wt %. Moreover, scanning electron microscopy and X‐ray photoelectron spectroscopy revealed that there were large amounts of nano‐Si absorbed on the surface of the hybrid composite microspheres, and the mean particle size became much larger when the loading amounts of nano‐Si reached 25 wt %. From this, it can be inferred that nano‐Si overflows from the inner core to the outside surface in the emulsification process and acts as an inorganic dispersant. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43101.     

Modification of surface properties of wool fabric with linde type a nano‐zeolite

Wool is a naturally occurring composite fiber consisting of keratin and keratin‐associated proteins as the key molecular components. The outermost surface of wool comprises a lipid layer that renders the surface hydrophobic, which hinders certain fabric processing steps and moisture management properties of wool fabrics. In this study, Linde Type A (LTA) nano‐zeolite (a Na⁺‐, Ca²⁺‐, and K⁺‐exchanged type A zeolite) was integrated onto the surface of wool using 3‐mercaptopropyl trimethoxy silane as a bridging agent. The resultant surface morphology, hydrophilicity, and mechanical performance of the treated wool fabrics were evaluated. Notably, the surface hydrophilicity of wool increased dramatically. When wool was treated with a dispersion of 1 wt % zeolite and 0.2 wt % silane, the water contact angle decreased from an average value of 148° to 50° over a period of approximately 5 min. Scanning electron microscopic imaging indicated good coverage of the wool surface with zeolite particles, and infrared spectroscopic evaluation demonstrated strong bonding of the zeolite to wool keratins. The zeolite application showed no adverse effects on the tensile and other mechanical properties of the fabric. This study indicates that zeolite‐based treatment is potentially an efficient approach to increasing the surface hydrophilicity and modifying other key surface properties such as softness of wool and wool fabrics. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42392.     

Calcium ion‐mediated grafting of a phosphate‐containing monomer

Grafting of monoacryloxyethyl phosphate onto expanded polytetrafluoroethylene was achieved using simultaneous grafting with the aim of improving the membrane wettability and mineralization capacity. This study explored the effect of adding calcium ions to the grafting solution and observed increased graft yield and wettability when compared with samples grafted in the absence of calcium ions. Fourier transform infrared spectroscopy mapping found the graft copolymer to be distributed in a patchy manner across the surface as well as throughout the membrane. Through X‐ray photoelectron spectroscopy analysis, it was found that calcium ions were incorporated into the graft copolymer and could be extracted using a basic ethylenediaminetetraacetic acid solution without reduction in graft yield. This implies that the presence of calcium ions is affecting the graft yield by increasing the local concentration of monomer near the surface during the grafting process. Investigation of the mineralization capacity of the grafted membranes in simulated body fluid revealed that the increased wettability of the membranes rather than the presence of the calcium ions affected the mineralization outcome. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42808.     

Improving the hydrophobicity of nylon fabric by consecutive treatment with poly(acrylic acid), tetraethylorthosilicate,and octadecylamine

Nylon fabric was consecutively treated with poly(acrylic acid) (PAA), tetraethylorthosilicate (TEOS), and octadecylamine (OA) to improve its hydrophobicity. We proposed that PAA could be used as a mediator between nylon and OA to provide a high density of the carboxyl moiety. TEOS was used to increase the surface roughness of the nylon fabric by hydrolysis and condensation, and OA was used to reduce the surface energy of the nylon fabric with its long alkyl chains. Both the increase in the surface roughness and the reduction in the surface energy contributed to the improvement of the hydrophobicity of the nylon fabric. The hydrophobicity of the treated nylon fabric was evaluated by the measurement of the water contact angle, water resistance to spray, and hydrostatic pressure. Scanning electron microscopy images showed that the surface roughness of the nylon fabric was significantly increased by treatment with TEOS. The nylon fabric with the PAA/TEOS/OA consecutive treatment exhibited a water contact angle of 125°, a resistance to water spray of 90, and a hydrostatic pressure of 275 mm. It was interesting to find that the PAA/TEOS/OA consecutive treatment slightly enhanced the wrinkle recovery but had no apparent effects on the degree of whiteness and the breaking strength of the nylon fabric. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42456.     

Surface and bulk analysis of bleaching soybean fabric in the presence of protein hydrolysate

The effect of oxidative and oxidative‐reductive bleaching on the colorimetric, topographical, and mechanical properties of soybean fabric has been investigated by yellowness index, abrasion resistance, tensile strength, Kawabata evaluation system for fabrics, scanning electron microscopy, X‐ray photoelectron spectroscopy, and time of flight secondary ion mass spectrometry in order to examine both the bulk and surface properties. Surface changes to the soybean fiber due to bleaching treatments have been evaluated and the protective effect of protein hydrolysates assessed. Improved tensile strength, flat abrasion performance, and handle maintenance of the soybean fabric was demonstrated with the incorporation of Byco C in both bleaching treatments. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Properties of (meth)acrylate copolymer grafted with long fluorinated side chain prepared by “graft onto” strategy

A (meth)acrylate copolymer grafted with long fluorinated side chains (AGLF) was synthesized successfully through a two‐step procedure. First, a carboxyl terminated fluoropolymer, poly(2,2,3,4,4,4‐hexafluorobutyl methacrylate) was synthesized by conventional radical polymerization in the presence of 3‐mercaptopropionic acid as chain transfer agent. And then the fluoropolymer was grafted to the in‐house synthesized polyacrylate (MMA‐r‐BA‐r‐GMA). Fourier transform infrared spectroscopy and ¹H‐nuclear magnetic resonance spectroscopy were employed to verify the synthesis of AGLF. Moreover, the surface properties were investigated by contact angle measurement and X‐ray photoelectron spectroscopy. The results proved that a small amount of poly(2,2,3,4,4,4‐hexafluorobutyl methacrylate) addition can create a hydrophobic surface effectively. Furthermore, the X‐ray photoelectron spectroscopy results showed that it is the AGLF grafted with longer fluorinated side chain that have more fluorine atoms enriched on the surface and thus performed better hydrophobicity and lipophobicity. Testified by thermogravimetric analysis and differential scanning calorimetry, it was found that AGLF films have excellent thermal properties. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 45894.     

Surface modification of poly(ethylene terephthalate) fibers via controlled radical graft polymerization

Functional chemical modifications on poly(ethylene terephthalate) (PET) fibers via radical graft polymerization could be controlled by managing mutual interactions and affinities between different components in the grafting reaction system. Hansen solubility parameters was used as a tool to quantify affinities of related agents and the polymer, and provided reliable results. The latest results proved the practicality of using Hansen solubility parameters in controlling radical graft polymerizations on surface modifications of PET fibers. Four different monomers with different hydrophilic properties in different solvent and initiator systems were examined, and results confirmed that interactions of initiator‐PET, initiator‐solvent, monomer‐PET, monomer‐solvent, and monomer‐initiator play important roles in determining the grafting reaction efficiency. Results revealed that for the selected grafting systems studied, hydrophilic monomers presented overall favoring affinities toward PET leading to higher grafting yields compared to hydrophobic monomers. The results have instructive impact to commercial applications. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 45990.     

Friction and wear properties of dumbbell‐shaped jute fiber‐reinforced friction materials

The surfaces of jute fibers (Corchorus capsularis L.) were processed to have different dumbbell‐shaped spacing (5 mm, 10 mm, 15 mm, and 20 mm), and the physical properties of the modified surfaces of the jute fibers were evaluated in this study. The dumbbell‐shaped jute fiber (DJF)‐reinforced friction materials were prepared through compression mold. The friction and wear performance of the DJF were tested using a friction material tester at constant speed. The results showed that the dumbbell‐shaped spacing has less influence on the friction coefficients of friction materials. The friction coefficients of DJF have bigger fluctuation compared with that of straight fiber during the temperature‐increasing procedure. The wear rate of DJF with dumbbell‐shaped spacing of 15 mm was the lowest, except for that when the temperatures were about 200–250°C. Morphologies of wear surfaces of DJF were observed using scanning electron microscopy and the friction characteristics were analyzed. The results showed that reinforced with DJFs in the friction materials can reduce the specific wear rate and the variation in friction coefficient compared with that of straight jute fibers. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40748.     

Surface‐tethered conjugated polymers created via the grafting‐from approach

Polyacrylate brushes with pendent terthiophenes [poly(terthiophene methyl methacrylate) (PTTMM)] were successfully grown from indium tin oxide and gold with surface‐initiated atom transfer radical polymerization. The films formed on both substrates were characterized by ellipsometry and Fourier transform infrared spectroscopy. Using cyclic voltammetry, we electrochemically crosslinked the PTTMM brush to form a conjugated polymer network. The conjugation lengths in the film were increased as evidenced by ultraviolet–visible spectroscopy. Additionally, an atomic force microscopy study on the surface‐modified solid substrate revealed the formation of a smooth and uniform polymer brush with a low surface roughness, even after electrochemical crosslinking. These uniformly grafted conducting polymer brushes may find use in photovoltaic devices. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41363.     

Surface modification of aramid fibers via ammonia‐plasma treatment

In this article, aramid fibers III were surface modified using an ammonia‐plasma treatment to improve the adhesive performance and surface wettability. The surface properties of fibers before and after plasma treatment were investigated by X‐ray photoelectron spectroscopy, scanning electron microscopy, atomic force microscopy, and water contact angle measurements. The interfacial shear strength of each aramid fibers III‐reinforced epoxy composites was studied by micro‐debonding test. The ammonia‐plasma treatment caused the significant chemical changes of aramid fibers III, introducing nitrogen‐containing polar functional groups, such as ? C? N? and ? CONH? , and improving their surface roughness, which contributed to the improvement of adhesive performance and surface wettability. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40250.     

The preparation of cotton fabric with super-hydrophobicity and antibacterial properties by the modification of the stearic acid

In this article, the superhydrophobic and antibacterial surface on the cotton fabric were fabricated with the UV curable waterborne coatings, the silver nanoparticles, and the stearic acid. The cotton fabric coated with silver stearate was obtained by immersing in a mixture of sodium hydroxide and then modified by stearic acid. Results showed that the water contact angle on the surface of the fabric was 157.6°. The micromorphology and chemical ingredients of the surface of the coating were studied by scanning electron microscope, Fourier transforms infrared spectroscopy, and X photoelectric spectrometer. Results showed that the immersion resulted in a double decomposition reaction and with the modification of the stearic acid, the silver stearate was formed on the surface, which provided a rough surface required for super-hydrophobicity. And the acid and alkali resistance test, water-resistance test, and antibacterial activity test indicated that the coating had good acid and alkaline resistance, water-resistance, and antibacterial properties.     

Surface modification of polyamide TFC membranes via redox‐initiated graft polymerization of acrylic acid

In this work, the redox‐initiated graft polymerization of acrylic acid (AA) onto the surface of polyamide thin film composite membranes has been carried out to enhance membrane separation and antifouling properties. The membrane surface characteristics were determined through the attenuated total reflection Fourier transform infrared spectra, scanning electron microscopy, atomic force microscopy, and water contact angles. The membrane separation performance was evaluated through membrane flux and rejection of some organic compounds such as reactive red dye (RR261), humic acid, and bovine serum albumin in aqueous feed solutions. The experimental results indicated that the membrane surfaces became more hydrophilic and smoother after grafting of AA. The modified membranes have a better separation performance with a significant enhancement of flux at a great retention. The fouling resistance of the modified membranes is also clearly improved with the higher maintained flux ratio and the lower irreversible fouling factor compared to the unmodified one. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45110.     

Photo‐mediated metal free atom transfer radical polymerization of acrylamide in water

Photo‐mediated metal free atom transfer radical polymerization of acrylamide was conducted at 25 °C in water under visible light irradiation with water soluble 2‐hydroxy‐3‐(4‐benzoylphenoxy)‐N,N,N‐trimethyl‐1‐propaminium chloride (HBTPC) as photoredox catalyst and 2‐hydroxyethyl 2‐bromoisobutyrate as alkyl halide. The polymerization followed first‐order reaction kinetics. The living character of photo‐mediated atom transfer radical polymerization of acrylamide was verified by the linear development of the polymer number average molar mass (M_n,GPC) with monomer conversion and narrow molecular weight distributions (?). The effects of acrylamide concentration, light intensity, amount of HBTPC, and tris(2‐dimethylaminoethyl)amine on polymerization were investigated. Increasing monomer concentration led to a higher M_n,GPC values with narrow ?. The polymerization rate increased with increasing the amount of monomer, light intensity, HBTPC and tris(2‐dimethylaminoethyl)amine. The polymerization was monitored by the periodic light on/off. The structure of polyacrylamide was analyzed by proton nuclear magnetic resonance spectrometer and gel permeation chromatography. Successful chain extension experiments show the controlled nature of the polymerization. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46567.     

Two‐stage stabilizer addition protocol as a means to reduce the size and improve the uniformity of polymer beads in suspension polymerization

A two‐stage stabilizer addition protocol is suggested for reducing the size and improving the uniformity of polymer beads resulting from conventional suspension polymerization. The stabilizer load was divided into an initial charge and a secondary addition. The use of a low concentration of stabilizer in the initial charge served to assist drop rupture while avoiding significant reduction in drop size and production of too many satellite droplets. The secondary addition time of stabilizer occurred just before the onset of the growth stage when drops were vulnerable to coalescence but robust against break up due to their high viscosity. The secondary addition of stabilizer served to provide stability to monomer drops during the growth stage and as a result the drops underwent limited coalescence. This resulted in the formation of smaller and more uniform polymer beads in comparison to beads obtained by conventional suspension polymerization at the same overall concentration of stabilizer. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 45671.     

Phase separation to create hydrophilic yet non‐water soluble PLA/PLA‐b‐PEG fibers via electrospinning

In moisture wicking fabrics, fibers with hydrophilic surfaces that are also non‐water soluble are desirable. In poly(lactic acid), PLA, fibers it is expected that the addition of poly(ethylene glycol), PEG, will monotonically increase their wicking rates. In this paper, phase separation was used to create biocompatible, biodegradable, hydrophilic yet non‐water soluble fibers by electrospinning PLA with PEG and PLA‐b‐PEG copolymers. By tuning the thermoelectric parameters of the apparatus, and the chemical properties of the dopes, the amount of PEG in the fibers was improved over prior work; concentration increased by 60% (by weight, wt %) to 16 wt % in the PLA fiber. Instead of the expected increasing wicking rates with PEG concentration, there is a peak at 12 wt %; at greater concentrations, wicking decreases due to PEG crystallization within the PLA (verified via DSC). At 12 wt % PEG from copolymers, the nanofabric's wettability increases to 1300% its original weight. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 41030.     

Graft modification of methyl acrylate onto chicken feather via surface initiated Cu(0)-mediated reversible-deactivation radical polymerization

In this study, chicken feather was functionalized with 2-Bromoisobutyryl bromide (BIBB) where methyl acrylate (MA) was grafted through Cu(0)-mediated reversible-deactivation radical polymerization (RDRP) catalyzed by copper wire. Feather-g-PMAs with three different target degrees of polymerization (Dp) were prepared fast. Besides, molecular mass of PMA was closely associated with the theoretical value; PMA also exhibited relatively low polydispersity (~1.17). The catalyst was removed through simple washing, and thus a colorless product was yielded. However, Cu(0)-mediated RDRP in the presence of the unmodified chicken feather caused the loss of control. Feather-g-PMA with a short graft chain exhibited a uniform interface coated on the feather fiber. Because the grafted PMA and the feather substrate had a strong interaction, and the graft ratio was less, there was only one stage of decomposition, and no glass transition temperature was detected. We detected a rough surface on feather-g-PMA with a longer graft chain and observed the glass transition of PMA and obviously two stages of decomposition. After densely graft, the hydrophilicity of chicken feather decreased. These feather-g-PMAs exhibited better compatibility in organic solvents (e.g., acetone and toluene). © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 48246.