Novel regenerable N‐halamine polymeric biocides. II. Grafting hydantoin‐containing monomers onto cotton cellulose

A novel cyclic‐amine monomer, 3‐allyl‐5,5‐dimethylhydantoin (ADMH) was synthesized with good yield by the reaction of allyl bromide with 5,5‐dimethylhydantoin (DMH), and was characterized by FTIR and ¹H‐NMR spectra. ADMH alone cannot be grafted onto other polymers. However, the presence of acrylonitrile markedly enhanced the ADMH graft yield onto cotton cellulose. The influence of reaction conditions on the graft copolymerization was investigated. After chlorine bleach treatment, hydantoin units in the grafted copolymers were easily transformed into N‐halamine structures. Grafted samples exhibited potent antibacterial activity against Escherichia coli, and the functional properties were shown to be durable and regenerable. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 617–624, 2001     

Novel refreshable N‐halamine polymeric biocides: Grafting hydantoin‐containing monomers onto high performance fibers by a continuous process

In this study, a continuous “pad‐dry‐cure” process was developed for the first time to graft a cycloamine monomer, 3‐allyl‐5,5‐dimethylhydantoin (ADMH), onto several high performance fibers, including Nomex, Kermel, and a PBI/Kevlar blend. The influence of reaction conditions on the grafting copolymerizaiton was studied. It was found that in the presence of a difunctional monomer, poly(ethylene glycol)–diacrylate (PEG–DIA), ADMH could be readily grafted onto these fibers. After exposure to chlorine, the hydantoin structures in the grafted samples could be transformed into N‐halamines, which provided powerful, durable, and regenerable antibacterial activities against both gram‐negative and gram‐positive bacteria. The influence of hydrophobic/rigid properties of the fabrics on grafting reactions as well as on their antibacterial activities was discussed, and the importance of full contact was emphasized. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 1032–1039, 2003     

Novel regenerable N‐halamine polymeric biocides. I. Synthesis,characterization, and antibacterial activity of hydantoin‐containing polymers

Two novel cyclic‐amine monomers, i.e., 3‐allyl‐5,5‐dimethylhydantoin (ADMH) and 7,8‐benzo‐3 allyl‐1,3‐diazasprio[4.5]decane‐2,4‐dione (BADDD) were synthesized with good yields by reacting allyl bromide with 5,5‐dimethylhydantoin (DMH) and 7,8‐benzo‐1,3‐diazasprio[4.5]decane‐2,4‐dione (BDDD), respectively. The synthesized monomers were characterized by FTIR and ¹H‐NMR spectra, and copolymerized with acrylonitrile (AN), vinyl acetate (VAC), and methyl methacrylate (MMA) in a small monomer ratio of ADMH and BDDD, respectively. The copolymers were characterized by FTIR, ¹H‐NMR, and DSC studies. The N‐halamine derivatives of the corresponding copolymers were found to exhibit high antibacterial activities against Escherichia coli, and the antibacterial properties were durable and regenerable. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 2460–2467, 2001     

Macroscopic N‐halamine biocidal polymeric beads

The particle size of N‐halamine biocidal polymers was methodically modified forming beads of different sizes by blending water‐insoluble N‐halamine polyurethane with sodium alginate as the matrix and loading heterocyclic rings onto modified silica gels. The biological activity of the prepared beads and halogenated modified silica derivatives was evaluated against examples of Gram‐positive (Staphylococcus aureus) and Gram‐negative (Escherichia coli) bacteria. The recycling possibilities and the optimum preparation conditions of the blended beads were investigated; blending prehalogenated polyurethane (5%, w/v) with sodium alginate (3%, w/v) followed by crosslinking with CaCl₂ (10%, w/v) at 40°C are the optimum preparation conditions for the alginate beads. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Biocidal polystyrene beads. III. Comparison of N‐halamine and quat functional groups

A comparison has been made between the biocidal efficacies of N‐chlorinated polymeric beads and two derivatives of polyquat beads. Biocidal effects were measured after brief contact exposures of aqueous suspensions of either Staphylococcus aureus or Escherichia coli to the water‐insoluble beads. The polymeric backbone was held the same in all three types of beads, so they differed only in their biocidal derivative moieties. In all cases, functionalization of crosslinked chloromethylated polystyrene beads was performed to introduce the biocidal properties. Synthetic methods and test data will be presented. The most effective biocide, as measured by degree of inactivation in the shortest contact time of the two species of bacteria, was the N‐chlorinated hydantoinyl derivative of methylated polystyrene. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 363–367, 2004     

Grafting of N‐carbamyl maleamic acid onto a styrene–butadiene–styrene copolymer

A styrene–butadiene–styrene block copolymer (SBS) was functionalized with N‐carbamyl maleamic acid (NCMA) using two peroxide initiators with the aim of grafting polar groups onto the molecular chains of the polymer. The influence of the concentration of benzoyl peroxide (BPO) and 2,5‐dimethyl, 2,5‐diterbuthylperoxihexane (DBPH) was studied. The concentration of peroxy groups ranged between 0.75 and 6 × 10^?4 mol % while the concentration of NCMA was constant at 1 wt %. The reaction temperature was chosen according to the type of peroxide employed, being 140°C for BPO and 190°C for DBPH. FTIR spectra confirmed that NCMA was grafted onto the SBS macromolecules. It was found that the highest grafting level was achieved at a concentration of peroxy groups of about 3 × 10^?4 mol %. Contact angle measurements were used to characterize the surface of the SBS and modified polymers. The contact angle of water drops decreased with the amount of NCMA grafted from 95°, the one corresponding to the SBS, to about 73°. T‐peel strength of polymer/polyurethane adhesive/polymer joints made with the modified polymers was larger than those prepared with the original SBS. The peel strength of SBS modified with 1.5 and 3 × 10^?4 mol % of peroxy groups from BPO were five times larger than that of the original SBS. The materials modified using BPO showed peel strengths higher than the ones obtained with DBPH. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 4468–4477, 2006     

Biocidal hydantoinylsiloxane polymers. IV. N‐halamine siloxane‐functionalized silica gel

The monomer 5,5‐dimethyl‐3‐(3′‐triethoxysilylpropyl)hydantoin and its hydrolysis product polymer poly[3‐(5,5‐dimethylhydantoinylpropyl)hydroxysiloxane] were employed to functionalize the surfaces of silica gel particles in order to produce an adhered film that becomes biocidal upon chlorination with dilute sodium hypochlorite bleach. The biocidal efficacy of the functionalized silica gel was demonstrated in a cartridge filter experiment against the bacterial pathogens Staphylococcus aureus and Escherichia coli O157:H7. Complete 6 log inactivations of the two bacterial species were observed within 30 s of contact. Moreover, upon loss of biocidal activity due to depletion of bound chlorine, the coated silica gel particles could be recharged by further exposure to dilute bleach. Potential uses of the biocidal silica gel include disinfection and odor control in water treatment facilities and recirculating baths. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 3448–3454, 2006     

Preparation of antibacterial cellulose with s‐triazine‐based quaternarized N‐halamine

To reduce the neutral salt used in the textile finishing with s‐triazine derivatives, a novel s‐triazine‐based quaternarized N‐halamine precursor was synthesized by two simple steps and characterized by H‐NMR and FT‐IR. This compound can be effectively coated onto cellulose by nucleophilic substitution process without neutral salt. The treated cellulose was rendered with powerful biocidal efficacy after transferring to an N‐halamine structure by exposing to dilute sodium hypochlorite solution through the synergistic antimicrobial effect quaternary ammonium salt and N‐halamine. The chlorinated samples could inactivate 6‐logs of Staphylococcus aureus and Escherichia coli O157:H7 within 1 min and 5 min, respectively. In addition, about 50% of oxidant chlorine remained after 50 washing cycles and 30 days storage, and all of the lost active chlorines in the N‐halamine molecules recovered after exposing to bleach solution. With these advantages, the as‐prepared antimicrobial fabrics will have potential application, especially in the medical and healthcare textiles. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44998.     

Reactivity ratios during radiation‐induced grafting of comonomer mixtures onto polyester fabrics

Radiation‐induced grafting of binary mixtures of acrylonitrile (AN)/styrene (S) and acrylamide (AAm)/styrene (S) onto polyester fabric (PET) has been investigated. Synergism during radiation grafting was investigated by determining the graft yield fraction for each monomer in the final graft copolymer. Moreover, by knowing the mole fraction of each monomer in the grafting solution, the reactivity ratio of the individual monomers in the comonomer mixture during graft copolymerization could be determined: in the case of AN/S comonomer mixture, the calculated reactivity ratios for AN and S are 0.04 and 0.05, respectively; the calculated reactivity ratios of AAm and S in their comonomer mixture are 1.82 and 0.41, respectively. © 2001 Society of Chemical Industry     

Antibacterial N‐halamine coating on cotton fabric fabricated using mist polymerization

3‐Methylallyloxy‐5,5‐dimethylhydantoin (MH), an methacrylate monomer containing N‐halamine moiety, was synthesized by 5,5‐dimethylhydantoin (DMH) and methacryloyl chloride. Antimicrobial coating of poly[1‐methyl‐1‐(4,4‐dimethyl‐2,5‐dioxoimidazolidin‐carbonyl)ethylene] (PMH) was prepared on cotton fabrics via “mist polymerization” using MH as monomer. The coating gave the cotton fabric with efficient antibacterial function with remarkable durability. In the antibacterial tests, the bacteriostatic reduction rate is greater than 99.78%, and can be maintained over 99.00% even after 30 washing cycles. Compared with other antimicrobial technologies, mist polymerization offers advantages such as achieving antimicrobial function by small consumption of monomer, forming coatings on single‐side of the fabrics, and minimizing the damages on the original properties of cotton during the finishing process. It can be applied in a wide variety of textile products such as sportswear, underwear, socks, and medical textiles. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44897.     

Grafting of N,N′‐methylenebisacrylamide onto cellulose using Co(III)‐acetylacetonate complex in aqueous medium

The grafting of N,N′‐methylenebisacrylamide (N,N′‐MBA) onto cellulose is carried out using the cobaltacetylacetonate complex (Co(acac)₃) under nitrogen atmosphere at 40°C. The rate of graft copolymerization has been studied as a function of [N,N′‐MBA], [Co(acac)₃], and temperature. The activation energy of grafting is found to be 156.0 k J mol⁻¹ within the temperature range of 30–60°C. The effect of perchloric acid, methanol, and surfactants on graft yield has also been studied and results are suitably explained. The higher efficiency of the metal chelate in initiation of graft copolymerization has been assumed due to the coordination of the π electrons of the N,N′‐MBA with the metal chelate, which facilitated the formation of the radicals through homolytic cleavage of metal–oxygen bond of the cobalt acetylacetonate complex. On the basis of the results, a suitable kinetic scheme for graft copolymerization is presented and rate expression is derived. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 76: 906–912, 2000     

Photografting of PVC containing N,N‐diethyldithiocarbamate groups with vinyl monomers

Poly(vinyl chloride) (PVC) with pendent N,N‐diethyldithiocarbamate groups (PVC–SR) was prepared through the reaction of PVC with sodium N,N‐diethyldithiocarbamate (NaSR) in butanone and used as a photoinitiator for the grafting polymerization of three vinyl monomers [styrene (St), methyl methacrylate (MMA), and acrylamide (Am)]. The effects of ultraviolet (UV) irradiation time, PVC–SR amount, and the monomer amount on grafting and grafting efficiency were investigated. The results showed that PVC–SR could initiate the polymerization of three vinyl monomers effectively and obtained crosslinked copolymers. The grafting and grafting efficiency of styrene and methyl methacrylate were higher than those of acrylamide. The polymerization activity of three monomers was acrylamide > methyl methacrylate > styrene. By analyzing the UV spectrum of PVC–SR with a different irradiation time, it was confirmed that PVC–SR was dissociated mainly into macromolecular the sulfur radical PVC–S · and the small molecular carbon radical · C(S)N(C₂H₅)₂; the grafting polymerization mechanism was discussed. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 77: 2569–2574, 2000     

Grafting onto cotton fiber with acrylamidomethylated β‐cyclodextrin and its application

To chemically attach β‐cyclodextrin (CD) molecules to cotton cellulose, N‐methylol‐acrylamide (NMA) was used to synthesize a CD containing monomer, which was then grafted onto cellulose fibers. Initiation of the cotton cellulose backbone with ceric ion before the addition of acrylamidomethyl cyclodextrin (CD‐NMA) monomer was shown to be beneficial for grafting onto cotton cellulose by studying the reactions of ceric ion with CD, CD‐NMA, or cotton cellulose. The amount of chemically attached CD was determined by fluorescence measurements and compared with graft yields. The possibility of textile finishing of CD containing cotton fibers was investigated using benzoic acid as an antibacterial finishing agent or vanillin as an aroma finishing agent. Antibacterial activity of benzoic acid‐treated samples were retained even after 10 laundering cycles and the vanillin fragrance lasted much longer compared with the control sample, suggesting that utilization of CD in functional textile finishing is indeed possible. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 78: 1986–1991, 2000     

Studies on acrylic acid–grafted polyester fabrics by electron beam preirradiation method. II. Novel intelligent immersion‐resistant and moisture‐permeable fabrics

Moisture regain, water vapor permeability, and water‐impermeable ability of polyester fabrics before and after grafting by acrylic acid (AA) were investigated. The results showed that the AA‐grafted fabric presents novel properties. When it is dry it possesses a higher water vapor transmission rate. Once it comes into contact with water, the grafted poly(acrylic acid) layer on the fibers' surface begins to swell and seals the intervals between fibers and yarns to prevent water from penetrating, a phenomenon known as immersion resistance. This kind of immersion‐resistant and moisture‐permeable fabrics might be a suitable candidate for the immersion‐resistant layer fabrics of Type B immersion‐resistant suits. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 3939–3943, 2003     

Regenerability of antibacterial activity of interpenetrating polymeric N‐halamine and poly(ethylene terephthalate)

Effective antibacterial modification of poly(ethylene terephthalate) (PET) was achieved by forming a surface thermoplastic semi‐interpenetrating network of polyacrylamide (PAM) and PET, followed by converting the immobilized amides to N‐halamine. The regenerability of N‐halamine on PAM‐modified PET was significantly influenced by the cross‐linkers used to form the network. Through Fourier transform infrared spectroscopy and nitrogen content analysis of the materials for up to 29 regeneration cycles, it was found that breaking down of the PAM network in chlorination accounted for the loss of regenerability. The relationship between antibacterial efficacy and N‐halamine concentration was also studied. Compared with N,N′‐methylenebisacrylamide and 2‐ethyleneglycol diacrylate, cross‐linker divinylbenzene can generate more durable PAM network. After 29 regeneration cycles, the PAM‐divinylbenzene network‐modified PET was still able to provide 100% reduction of healthcare‐associated methicillin‐resistant Staphylococcus aureus in 20 min contact. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Synthesis of polysiloxane with 5,5‐dimethylhydantoin‐based N‐halamine pendants for biocidal functionalization of polyethylene by supercritical impregnation

An N‐halamine precursor 3‐(3‐hydroxypropyl)‐5,5‐dimethylhydantoin (HPDMH) has been synthesized. The N‐halamine precursor was reacted with poly(methylhydrosiloxane) (PMHS) to produce a biocidal polysiloxane with 5,5‐dimethylhydantoin‐based N‐halamine pendants through silane alcoholysis and subsequent chlorination of hydantoin ring with tert‐butyl hypochlorite. The N‐halamine polysiloxane was impregnated into inert polyethylene (PE) fibers and formed a 68‐nm coating layer in supercritical carbon dioxide (scCO₂) for antibacterial application. The PE fibers before and after impregnation were characterized by XPS and SEM. The N‐halamine polysiloxane impregnated PE samples provided effective biocidal activities against both Staphylococcus aureus and Escherichia coli compared with unmodified ones that did not display obvious antibacterial activities. The coating layer on PE substrate was stable toward washing cycles, storage, and UV irradiation and the rechargeability of lost active chlorines was good. The scCO₂ impregnation approach uses environmentally friendly CO₂ as solvent and can be applied to both reactive and nonreactive substrates since it does not require covalent bonds to tether biocidal moieties. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44721.     

Studies on salts of amine‐containing polymers with benzoic acids. III. Poly(N,N‐dimethylaminoethyl methacrylate‐g‐polyethylene) with benzoic acids

Poly(N,N‐dimethylaminoethyl methacrylate) [poly(DMAEMA)] was grafted onto a commercial polyethylene film by means of γ‐irradiation, and the grafted films were reacted with various liquid‐crystal‐forming benzoic acids. When polymeric salts consisting only of poly(DMAEMA) and the benzoic acids were heated, dissociation of salts was observed, but with poly(DMAEMA) grafted onto polyethylene films, salt dissociation or crystallization of dissociated acids could be avoided, and interesting morphologies, including liquid‐crystal phases, were observed for the systems of benzoic acids–poly(DMAEMA‐g‐polyethylene). © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 78: 972–978, 2000     

Novel polyion complex films from chitosan and quarternized poly(4‐vinyl‐N‐carboxymethylpyridine) containing zwitterion structure units

Novel polyion complexes films of chitosan and quarternized poly(4‐vinyl‐N‐carboxymethylpyridine) containing zwitterion structure units were prepared by casting method. The aim of this work was to produce a hydrophilic film with the potential use as a hydrophilic membranes of the types used in membranes distillation and osmotic distillation for separating azeotropic, close‐boiling, and aqueous organic mixtures. Their structure and properties were studied by infrared, wide‐angle X‐ray diffraction, scanning electron microscopy, thermogravimetric analysis, tensile tester, and swelling measurements. The results indicated that polyion complexes occurred between chitosan and quarternized poly (4‐vinyl‐N‐carboxymethylpyridine) containing zwitterion structure units. The thermostability of these blends decreased with the increase of quarternized poly(4‐vinyl‐N‐carboxymethylpyridine) content. Initially, appreciable improvement in tensile strength and breaking elongation were achieved with increase of quarternized poly(4‐vinyl‐N‐carboxymethyl‐pyridine) content to 30%, the maximum value of 46.65 MPa tensile strength and 25.67% breaking elongation were achieved, respectively. The maximum degree of swelling was achieved when the weight ratio of chitosan versus poly(4‐vinyl‐N‐carboxymethylpyridine) was 50 : 50. Meanwhile, the relationship between their structure and properties was also discussed. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007     

Processes involved during radiation grafting of N‐vinyl pyrrolidone onto poly(ethylene terephthatate) fabric

Kinetics of radiation grafting of N‐vinyl pyrrolidone (NVP) onto poly(ethylene terephthalate) (PET) fabric revealed the existence of four different processes. These are as follows: the grafting, the homopolymerization, the degradation, and the diffusion. The grafting process was followed by the increase in weight with the increase in irradiation time (t), while the homopolymerization and the degradation processes were evaluated from changes in the square root of the specific viscosity of the irradiated monomer solution (√η_sp) with the increase in t. All processes were carried out at different NVP concentrations, different irradiation temperatures (T), and a dose rate 1.31 Gy s^?1. All processes followed first‐order kinetics except the degradation process that followed a 0.6‐order. The rate (R) and rate constant (k) of grafting and diffusion processes were found to increase with the increase in T, while the homopolymerization and degradation processes showed negative temperature dependence. The sum of R of the four processes was proportional to the initial NVP concentration, while k of the four processes was independent of T and has a value of 0.674 min^?1. The respective apparent activation energies of 24.0, 6.24, 6.84, and 2.5 kJ mol^?1 were calculated for the four processes. The NVP molecules participated in each process and their energies were evaluated. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 3009–3022, 2006     

Novel polymerizable N‐aromatic maleimides as free radical initiators for photopolymerization

Four kinds of polymerizable N‐aromatic maleimides (MIs)—4‐[(4‐maleimido)phenoxy]benzophenone (MPBP), 4,4′‐bis[(4‐maleimido)phenoxy]benzophenone (BMPBP), 4‐maleimidobenzophenone (MBP), and 4,4′‐bismaleimidobenzophenone (BMBP)—were synthesized as free radical photoinitiators, by introducing directly N‐phenylmaleimide groups or maleimide groups into the molecule of benzophenone (BP). Compared with BP, their UV‐visible spectra have a significantly red‐shifted maximum absorption. The maximum absorption of MIs containing bifunctional maleimide groups is slightly larger than the corresponding monofunctional ones. Choosing an unsaturated tertiary amine N,N‐dimethylaminoethyl methacrylate (DMAEMA) as coinitiator, the photopolymerization of 1,6‐hexanediol diacrylate (HDDA), initiated by these four MIs, was studied through photo‐DSC. The results show that all the MIs are dramatically more efficient than BP. Among them, MPBP is the most efficient, in which the polymerization rate is almost three times as high as that of the BP system. Photoinitiators containing bifunctional maleimide groups, though having higher final conversion, are less efficient than the corresponding monofunctional ones. These polymerizable photoredox systems significantly reduced the migration of the active species, leading to their higher efficiency. Copyright © 2006 Society of Chemical Industry