Preparation of antimicrobial sutures by preirradiation grafting of acrylonitrile onto polypropylene monofilament. III. Hydrolysis of the grafted suture

Polypropylene‐grafted‐polyacrylonitrile (PP‐g‐PAN) sutures were prepared by graft polymerization of acrylonitrile onto polypropylene (PP) monofilament using a preirradiation method. The grafted PP monofilaments were subsequently hydrolyzed to introduce carboxyl groups for antimicrobial drug immobilization. The maximum conversion of nitrile groups into carboxyl groups was limited to about 62% and produced sutures with carboxyl content ranging from 0.042 to 0.25 mmol/g. The physical characteristics of sutures were evaluated by FTIR, X‐ray diffraction, differential scanning calorimetry, and X‐ray photoelectron spectroscopy. In general, the hydrolysis did not cause any significant variation in crystalline structure. The mechanical strength was affected in all the grafted sutures. The tensile strength of sutures was investigated as a function of the degree of grafting. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 2509–2516, 2004     

Surgical suture materials with antimicrobial properties

Methods and manufacturing conditions were developed for giving ion-exchange properties to PCA fibres by graft polymerization of methacrylic acid to PCA fibres and styrene to PP fibres followed by sulfurization of the graft polystyrene. Antimicrobial surgical suture materials with fixation of antibiotics on the modified sutures by the ion-exchange mechanism were obtained. It was found that the duration and effectiveness of the antimicrobial action of the sutures are determined by the amount of antibiotic sorbed and the ionic bond strength of the latter with the ion-exchange groups in the sutures. The effect of the conditions of modification and methods of sterilization on the physicomechanical properties of the sutures was investigated. Antimicrobial surgical PCA sutures with the gentamycin Caprogent are recommended for use in general clinical practice and are being manufactured. __________ Translated from Khimicheskie Volokna, No. 2, pp. 37–43, March–April, 2007.     

Preparation of antimicrobial sutures by preirradiation grafting of acrylonitrile onto polypropylene monofilament. II. Mechanical,physical, and thermal characteristics

Polypropylene‐g‐polyacrylonitrile sutures were prepared by graft polymerization of acrylonitrile onto polypropylene monofilament by preirradiation method. Sutures with various graft levels were characterized by Fourier Transform Infrared Spectroscopy (FTIR), Density, Birefriengence, X‐ray Diffraction, Scanning Electron Microscopy (SEM), and Differential Scanning Calorimetry (DSC). Mechanical properties of the unmodified and grafted sutures were also evaluated. The physical characteristics of sutures were markedly affected by the graft levels. Density of the polypropylene sutures increased with an increased in the degree of grafting. The heat of fusion and heat of crystallization decreased with the increase in the degree of grafting. X‐ray diffraction also revealed decrease in crystallinity with the increase in the graft levels. Tenacity of the monofilament improved, whereas the elongation at break decreased in grafted samples. Scanning electron microscopy showed significant variation in surface morphology in the grafted samples. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 1224–1229, 2004     

Study of modified polypropylene nonwoven cloth. II. Antibacterial activity of modified polypropylene nonwoven cloths

Removal of E. coli from water by modified polypropylene (PP) nonwoven cloths which were prepared through radiation‐induced grafting of 4‐vinyl pyridine (4‐VP) onto PP nonwoven cloths and followed by quaterization was carried out by filtration. The results showed that the content and structure of the pyridinium group on PP nonwoven cloths were important factors to affect their antibacterial activity. The antibacterial activity increased with the number of piled sheets of the used nonwoven cloths and decreased with increase of the viable bacterial cell concentrations in the influent and with filtration rates. The activity detection results found that modified PP nonwoven cloths possessed the ability to capture the bacterial cell alive, and no morphological changes of adhered bacterial cells were observed using SEM; thus, the surfaces of the modified PP nonwoven cloths may not be bactericidal, but bacteriostatic. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 77: 1869–1876, 2000     

Preparation of nonleaching antimicrobial polypropylene wax and its application in polypropylene

Antimicrobial polypropylene (PP) has been widely used. Its highly effective antimicrobial activities and nonleaching characteristics remain concerns. In this study, polypropylene wax (PPW) grafted with maleic anhydride was first prepared; this was followed by a melting reaction with polyhexamethylene guanidine hydrochloride (PHMG) to obtain antimicrobial PPW [polypropylene wax grafted with polyhexamethylene guanidine hydrochloride (PPW‐g‐PHMG)]. PPW‐g‐PHMG was then melt‐blended with PP to prepare antimicrobial PP. Fourier transform infrared spectra confirmed that PHMG was covalently bonded on the PPW chains, and transmission electron microscopy images showed a uniform distribution of PHMG in the PPW matrix. The resulting antimicrobial PP exhibited excellent antimicrobial activity against Escherichia coli. The ring‐diffusion test further disclosed its nonleaching characteristics. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44190.     

Rheology and morphology of polypropylene in situ grafted and blended with methyl methacrylate/n‐buthylacrylate copolymer

The rheology and morphology of polypropylene (PP) modified by grafting and blending with vinyl monomers were studied in this work. The PP powder was impregnated by mixture of methyl methacrylate (MMA)/n‐buthylacrylate (n‐BA) and copolymerized with azobisisobutyronitrile (AIBN) initiator. The simultaneous grafting and blending of PP with MMA‐co‐n‐BA copolymers were performed in a corotating, 40 L/D, twin‐screw extruder in the presence of dicumyl peroxide. The Fourier transform infrared spectroscopy (FTIR) and Scanning Electron Microscopy (SEM) were used to verify the grafting level and dispersion state of MMA/n‐BA copolymer on PP matrix, respectively, and their rheological properties were studied. It is observed that MMA/n‐BA copolymer is finely dispersed in the PP matrix. In this way, PP can be grafted, blended, and simultaneously compatibilized with polar copolymers, as is seen in SEM images. The results showed that by increasing acrylate monomers grafting on to PP increased. The same trend was observed for AIBN initiator. The gel content of samples with 25% monomers showed an increased from 0.7% to 3.5% by increasing AIBN from 0.2% to 0.4%. The grafting reaction took place with chain scission of PP molecules and also cross‐linking reactions. The optimum grafting of 7.3% with lowest chain scission and cross‐linking were obtained for samples containing 15 wt% monomer and 0.3% AIBN initiator. J. VINYL ADDIT. TECHNOL., 21:290–298, 2015. © 2014 Society of Plastics Engineers     

Creation of Sutures with Antimicrobial Properties

It was found that Decamethoxin, as a broad-spectrum antiseptic with a pronounced antibacterial and fungicidal action, and BF-6 phenol-polyvinylacetal adhesive, which gives complex sutures the structure of a pseudomonofilament, are best as antimicrobial additives in a modifying composite for giving surgical sutures antimicrobial properties. A Decamethoxin content in the modifying composite of 10% of the weight of BF-6 (1.7–2.0% in the suture) is sufficient for manifestation of the antimicrobial effect with respect to Staphylococcus aureus, E. coli, and yeast-like fungi. The antimicrobial activity of a suture with a 1.7–2.0 wt. % decamethoxin content in the period from 2 to 24 h increases by 4 times with respect to E. coli and by 8 times with respect to Staphylococcus aureus and yeast-like fungi. Application of a coating of BF-6 adhesive with Decamethoxin has almost no effect on the physicomechanical properties of the sutures, but the capillarity decreases significantly (by ∼86%), which also decreases the probability of wound infection. The kinetics of release of Decamethoxin does not change after radiation sterilization of the sutures, i.e., the composition and content of the antimicrobial additive in the modified sutures and its antimicrobial activity are preserved. The optimum medium for storage of sterile modified sutures is 1% Decamethoxin solution. After 12 days of storage, the sutures remain sterile and lose a maximum of 6% of the breaking strength. Institute of Problems of Materials Science, National Academy of Sciences of Ukraine, Kiev. Translated fromKhimicheskie Volokna, No. 4, pp. 47–52, July–August, 2000.     

Development of antimicrobial polypropylene sutures by graft polymerization. I. Influence of grafting conditions and characterization

Modification of polypropylene monofilament was carried out by the graft polymerization of 1‐vinylimidazole (VIm) using simultaneous radiation grafting method. The effect of radiation dose, monomer concentration, and the grafting medium on the degree of grafting was evaluated. It was observed that the presence of organics as additives in the reaction medium had significant influence on the graft levels. These grafted sutures were characterized using several techniques, such as infrared spectroscopy (IR), X‐ray diffraction, and differential scanning calorimetry (DSC). It was found that the grafts are confined to the amorphous region of the monofilament and the crystalline regions remain intact. The surface morphology of sutures was evaluated by scanning electron microscopy. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 3895–3901, 2006     

Degradation and drug‐release studies of a poly(glycolide‐co‐trimethylene carbonate) copolymer (Maxon)

Poly(glycolide‐co‐trimethylene carbonate) is available commercially as a monofilament suture known as Maxon. The literature has shown that Maxon sutures possess a slow degradation rate of about 7 months and exhibit relatively high mechanical strength in comparison with other absorbable sutures. However, very few articles are available on the degradation of unoriented Maxon. This study was designed to explore the chemical and physical aspects of the degradation of unoriented Maxon and its potential as a drug‐release device. Several analytical techniques were used, including mass measurements, simultaneous small‐angle X‐ray scattering and wide‐angle X‐ray scattering, and thermoporometry. Magnetic resonance imaging and drug‐release measurements were carried out with UV spectroscopy. The results suggest that unoriented suture‐based Maxon undergoes multiple stages of hydrolytic degradation, which involve hydration, and active and postactive periods. The drug‐release mechanism is controlled by diffusion in the early degradation stages and polymer erosion in the later stages of release. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 95: 475–486, 2005     

Graft copolymerization studies. III. Methyl methacrylate onto polypropylene and polyethylene terephthalate

The tert‐butoxy radical‐facilitated grafting of methyl methacrylate (MMA) onto commercial polypropylene (PP) pellets and fiber was investigated in heterogeneous conditions similar to practical systems. Free‐radical grafting of several other monomers onto PP fiber was also investigated. Also, preliminary data from the grafting of MMA onto poly(ethylene terephthalate) pellets is presented. The PP‐graft‐PMMA residues were detected by solid‐state ¹³C‐NMR and photoacoustic IR spectroscopy. There was a good correlation between the degree of grafting (DG) determined from these spectroscopic techniques and the results from gravimetric methods. A maximum grafting efficiency of over 50% was found, whereas DG (20%) remained constant at various PP pellet, initiator, and monomer concentrations. However, at relatively low PP fiber concentrations, the DG was 27%; the increase was most likely due to the greater surface area of the fiber. There was also a reduction in DG (14%) at relatively low initiator concentrations. The reaction conditions were altered to favor grafting by the addition of more polymer substrate. When the ratio of tert‐butoxy radicals to PP was decreased, more of the substrate remained unmodified, and empirical calculations showed the formation of grafts with up to 40 monomer units. At high initiator concentrations, calculations showed that the graft residues were 1–2 units long. Therefore, variation of the polymer, initiator, and monomer concentrations was shown to have a significant effect on grafting. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 898–915, 2002     

Atmospheric plasma‐aided biocidal finishes for nonwoven polypropylene fabrics. I. Synthesis and characterization

Novel biocidal fabrics were synthesized by the graft copolymerization of glycidyl methacrylate (GMA) onto plasma‐treated nonwoven polypropylene (PP) to produce PP/GMA grafts. Atmospheric oxygenated helium plasma was used to enhance the PP fabrics' initiation before GMA grafting. The grafted PP/GMA epoxide group was reacted with β‐cyclodextrin, monochlorotrizynyl‐β‐cyclodextrins, or a quaternary ammonium chitosan derivative [N‐(2 hydroxy propyl) 3‐trimethylammonium chitosan chloride]. Some interesting biocidal agents were complexed into the cyclodextrin (CD) cavity of PP/GMA/CD grafted fabrics. Fourier transform infrared spectroscopy, thermogravimetric analysis, differential scanning calorimetry, and optical and scanning electron microscopies were used to characterize the grafted complexed fabrics. These synthesized biocidal fabrics proved to be antistatic, antimicrobial, and insect‐repelling (see part II of this study). © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 1900–1910, 2007     

Improved antimicrobial activity of polypropylene and cotton nonwoven fabrics by surface treatment and modification with chitosan

Nonwoven polypropylene and cotton fabrics were subjected to plasma pretreatment followed by flash evaporation and radiation crosslinking acrylate polymer coating, which is based on a vacuum deposition, solvent free, process that produces high quality, uniform fabrics with various thicknesses (0.05–5.0 μm). These treated fabrics were then dipped into chitosan, carboxymethyl chitosan, and carboxymethyl chitin solution. These polysaccharides form strong complexes with the modified surface. The antimicrobial activity of these treated samples was then evaluated for their antifungal and antibacterial properties. The antifungal activity for Fusarium oxysporum f. sp. lycopersici, Verticillium albo‐atrum, and Alternaria solani (A. alternata) were examined by the disc plate method. The antibacterial activities of the modified fabrics against Clavibacter michiganensis and Pseudomonas solanacearum were also examined by the viable cell counting method. The inhibition zone of the chitosan covered samples has increased by a factor of 2–3.1 over the original pretreated samples. The chitosan‐modified fabrics showed a good antibacterial activity in killing almost 10⁵ cells/mL within 18–23 h. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Polypropylene/polypropylene‐grafted acrylic acid blends for multilayer films: Preparation and characterization

Polypropylene (PP) was functionalized with acrylic acid (AA) and styrene (st) as a comonomer by means of a radical‐initiated melt‐grafting reaction. FTIR, ESCA, and ¹H‐NMR spectroscopies were used to characterize the formation of polypropylene grafted with acrylic acid (PP‐g‐AA) and polypropylene grafted with acrylic acid and styrene (PP‐g‐AAst). The content of AA grafted onto PP was determined by using volumetric titration. Blends of PP with 0–100 wt % of PP‐g‐AA were prepared by melt mixing. The effect of the modified polymer content on the surfaces of cast films was characterized through FTIR–ATR and ESCA analysis as well as contact‐angle, wetting‐tension, and ink‐adhesion measurements. The influence of the content of AA on the melting and crystallization temperature of PP was investigated by DSC. The contact angles of water on cast‐film surfaces of PP/PP‐g‐AA blends decreases with increasing modified polymer content and decreasing PP‐g‐AA molecular weight. A notorious improvement on wetting tension was observed with increasing modified polymer content and decreasing PP‐g‐AA molecular weight. From FTIR–ATR and ESCA spectra of the blends, a calculation was made of the carbonyl index on the films' surfaces. It was found that the higher the carbonyl index, the lower the contact‐angle value for the polypropylene blends. An increase in crystallization temperature of PP was observed when AA monomers were grafted into PP and with increasing PP‐g‐AA content in the blend, probably caused by a nucleation effect of AA monomers that would improve the crystallization capability of PP. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 79: 1497–1505, 2001     

Development of a nanocomposite of polypropylene with biocide action from silver nanoparticles

This article presents the production of films based on blends of polypropylene (PP) and modified PP with the insertion of silver nanoparticles (AgNPs) produced to generate a bactericidal effect. The 50/50 blend of PP and PP modified by irradiation in acetylene at a dose of 12.5 kGy was processed in a twin‐screw extruder. The addition of AgNPs in poly(N‐vinyl‐2‐pyrrolidone) (PVP) solution was performed during processing in the extruder. The material was characterized by ultraviolet–visible spectroscopy, scanning electron microscopy, energy‐dispersive spectroscopy, transmission electron microscopy, cytotoxicity assay, and a reduction in colony‐forming units. The PP–PVP1% AgNP film showed silver particles in the nanoscale, presented no cytotoxicity for mammalian cells, and presented antimicrobial effects against Gram‐negative Escherichia coli and Gram‐positive Staphylococcus aureus bacteria. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42218.     

Study of multi‐monomer melt‐grafting onto polypropylene in an extruder

Free‐radical melt‐grafting of the dual‐monomer systems glycidyl methacrylate–styrene (GMA‐St) and hydroxyethyl methacrylate–styrene (HEMA‐St) onto polypropylene (PP) has been studied using a single‐screw extruder. For single monomer grafting systems, degradation of PP was unavoidable and deterioration of the mechanical properties of the grafted PP subsequently occurred because of β‐scission of PP chains during the free‐radical melt‐grafting process. However, for the dual‐monomer systems, it is shown that the addition of styrene as a comonomer can significantly enhance the GMA or HEMA grafting levels on PP and reduce the extent of β‐scission of PP backbone. It has been found that the grafting degree of dual‐monomer melt‐grafted PP, such as PP‐g‐(GMA‐co‐St) or PP‐g‐(HEMA‐co‐St), is about quadruple that of single‐monomer grafted PP for the same monomer and dicumyl peroxide concentrations. Moreover, the melt flow rate of the dual‐monomer grafted PP is smaller than that of the unmodified PP. Hence, PP not only was endowed with higher polarity, but also kept its good mechanical properties. © 2000 Society of Chemical Industry     

Biocidal polymers: Synthesis,antimicrobial activity,and possible toxicity of poly (hydroxystyrene‐co‐methylmethacrylate) derivatives

Functionalized polymers have gained much interest in the last decades. This is due to their functional group and their polymer nature that give them unique properties and more advantages than the corresponding small molecules. In this trend, polyhydroxystyrene‐co‐MMA was modified to introduce amino group in the side chain of the polymer. The amine modified polymer was reacted with two classes of active compounds. The first class is aldehydes such as vanilline, p‐hydroxybenzaldehyde, p‐chlorobenzaldehyde, and anisaldehyde. The second class is phenolic esters such as p‐hydroxymethylbenzoate, 2,4‐dihydroxymethyl benzoate, and methyl salicylate. The antimicrobial activities of the polymer and modified polymer with these two classes were explored with Gram‐negative bacteria (Escherichia coli), Gram‐positive bacteria (Bacillus subtilus), fugus like yeast (Candida albicans SC5314), and pathogenic molds (Aspergillus flavus, Trycophyton rubrum, and F. oxysporium). In vitro studies indicated that the start polymer did not affect on the test microorganisms, in contrary to its derivatives. The diameter of inhibition zone varied according to the active group in the modified polymer, polymer microstructure, and the test microorganism. Derivatives I, II, and III were selected among the most effective antimicrobial compounds. Their inhibitory effects on the ratio of surviving cell number (M/C) increased by increasing derivatives concentrations. Derivatives I and II were inhibitorier to C. albicans and molds than to bacteria while derivative III was only antibacterial. These derivatives seemed toxic to Brine shrimp by increasing their concentrations above 10 ppm, with derivative III being the less toxic, compared to others. To clarify this toxic effect and to decrease the toxicity of these derivatives, more detailed studies are necessary, and this will be focused in the nearest future. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Characterization and application of polypropylene films modified with stimuli‐sensitive copolymers with an Ar‐plasma postpolymerization technique

Surface‐modified polypropylene (PP) films with thermally and photochemically sensitive copolymers consisting of N‐(2‐hydroxypropyl)methacrylamide (HPMA) and 4‐(4‐methoxyphenylazo)phenyl methacrylate (MPAP), poly(HPMA‐co‐MPAP)‐g‐PP (abbreviated g‐PP) film, were prepared by graft copolymerization with an Ar‐plasma postpolymerization technique. The surfaces of the g‐PP films were characterized by means of X‐ray photoelectron spectroscopy; the percentage grafting of poly(HPMA‐co‐MPAP) with a number‐average molecular weight of 3.28 × 10⁴ was 7.12%, and the molar ratio of HPMA–MPAH in the copolymer was 0.75:0.25. The stimuli‐sensitive adsorption of albumin and polystyrene microspheres on the g‐PP film was also measured. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 143–148, 2003     

Enhancing antibacterial properties of polypropylene/Cu‐loaded montmorillonite nanocomposite filaments through sheath–core morphology

Polypropylene (PP) loaded with copper‐exchanged montmorillonite (Cu‐MMT) nanocomposite filaments and films with excellent antimicrobial activity have been reported for the first time. A sheath–core morphology filament in which only the sheath contains Cu‐MMT was prepared for maximizing bioactivity. Sodium MMT clay was modified to acid‐activated MMT and further to Cu‐MMT via an ion exchange process. The exchange operation was confirmed using wide‐angle X‐ray diffraction and energy‐dispersive X‐ray spectroscopy (EDX) which suggested increased interlayer spacing and confirmed the loading of copper in Cu‐MMT. Further, Cu‐MMT was melt‐mixed in PP in the form of PP/Cu‐MMT nanocomposite filament, film and sheath–core morphology PP/Cu‐MMT nanocomposite filament. The surface morphology and elemental composition of the nanocomposites were studied using scanning electron microscopy coupled with EDX. Transmission electron micrographs were obtained to understand the dispersion characteristics of Cu‐MMT phase in PP. X‐ray diffraction analysis of nanocomposites suggested increased crystallinity at lower loading due to heterogeneous nucleating action of MMT. The PP nanocomposite filaments and films were tested for antimicrobial activity against Gram‐negative bacterium Escherichia coli, which is the main pathogenic bacterium found abundantly in water, and were found to exhibit excellent antimicrobial activity. © 2018 Society of Chemical Industry     

Solid‐state graft polymerization of styrene in spherical polypropylene particles in the presence of montmorillonite

In this work, cetyltrimethyl ammonium bromide and methacryloyloxyethyhrimethyl ammonium chloride were used to prepare organophilic montmorillonite (O‐MMT). Then, polypropylene (PP)–clay nanocomposites were prepared by the in situ grafting polymerization of styrene (St)‐containing O‐MMT onto PP with tert‐butyl perbenzoate as an initiator in the solid state. Fourier transform infrared spectroscopy, gel permeation chromatography, transmission electron microscopy, and X‐ray diffraction were applied to study the structure of the layered silicate and modified PP. The surfaces of the composites and, thus, the distribution of the clay in the PP matrix were characterized by scanning electron microscopy. The rheology and mechanical properties were studied and are discussed. According to the characterization results, OMMT and St were already grafted onto the PP main chain. Also, the intercalated structure of montmorillonite could be stabilized, and a stable exfoliated structure could be attained. Namely, intercalated PP/OMMT nanocomposites were obtained. The rheological results clearly show that these PP/OMMT nanocomposites had long‐chain‐branched structures. The peroxide modification of PP had minor effects on the tensile and bending strengths of the modified PP; however, this modification resulted in a significant reduction in the impact strength. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Surface grafting of styrene on polypropylene by argon plasma and its adsorption and regeneration of BTX

Active macromolecular free radicals were generated on polypropylene (PP) fiber surfaces by argon plasma irradiation, and surface‐modified PP fibers (PP‐g‐St fibers) were prepared by in situ grafting reaction of styrene monomers (St). The prepared samples were characterized by Fourier transform infrared, NMR, X‐ray photoelectron spectroscopy, scanning electron microscopy, and thermogravimetric analysis. Effects of reaction parameters on grafting percentage were studied, and adsorption capacities of PP‐g‐St fibers for benzene, toluene, and xylene (BTX) were evaluated. Regeneration adsorption efficiencies after adsorption of pure BTX and BTX emulsion and solution in water were explored. The results indicated that, using pure St as the monomer, the optimum input power, irradiation time, and grafting reaction time are 90 W, 3 min, and 3 h, respectively, and the grafting percentage of St reached 5.7% when pure St was used. The characterization results demonstrated that St was grafted onto the surface of the PP fibers. Compared to pristine PP fibers, the adsorption capacities of PP‐g‐St fibers toward toluene and xylene emulsions and solutions in water increased. In addition, regeneration adsorption efficiencies of modified fibers remained >90% after six cycles of regeneration adsorption experiments, which showed excellent regeneration ability. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46171.