Nonwoven Polypropylene Research Articles

Synthesis and Durable Antimicrobial and Anti-fungal Properties of Triclosan and Chitosan Co-grafted Polypropylene Nonwovens

Synthesis and Durable Antimicrobial and Anti-fungal Properties of Triclosan and Chitosan Co-grafted Polypropylene Nonwovens

Antiviral respiratory masks with plasma-functionalized polypropylene textiles for optimal adsorption of antiviral substance

During the COVID-19 pandemic, face masks were the first line of defense against the spread of infection. However, infectious viruses may remain on medical textiles, potentially serving as an additional source of infection. Due to their chemical inertness, many textiles cannot be enhanced with antiviral functionalities. Through treatment with low-pressure gaseous plasma, we have activated the surface of a medical-grade melt-blown, non-woven polypropylene textile so that it can absorb sodium dodecyl sulfate, an antimicrobial surfactant. Within two hours of contact time, the functionalized textile has been able to inactivate over 7 log10 PFU mL−1 of bacteriophage phi6, a surrogate of enveloped viruses such as SARS-CoV-2, and it has retained its antiviral properties for over 100 days. The functionalized material has not disrupted facial mask filtration efficiency or breathability. In addition, the in vitro biocompatibility testing in accordance with ISO 10993-5 for testing of medical devices has demonstrated that the selected formulation causes no adverse effects on the mouse fibroblast cell line L-929. With the treatment processes that have been completed within seconds, the method seems to have great potential to produce antiviral textiles against future outbreaks.

Enhancing the coloration of polypropylene surfaces through low-frequency plasma modification with disperse dyes

This study focuses on the effective coloring of nonwoven polypropylene surfaces, achieved through the application of oxygen and nitrogen plasma treatments in a vacuum environment using cold plasma. Various plasma durations were employed to introduce experimental diversity into the samples. Following surface modification, dispersal dyeing based on benzenesulphonamide was performed. To evaluate the impact of surface modification, comprehensive characterization tests, including SEM, FTIR-ATR, XRD, and XPS, were conducted. Performance effects were scrutinized through color spectrum values (CIE L*, a*, b*, and K/S values), tearing strengths and contact angle measurements. Furthermore, fastness tests for washing (color change and staining) and for rubbing (dry and wet) were carried out to examine the effect of surface modification on dyed polypropylene nonwoven fabrics. According to the test results, a notable increase in K/S values was observed after plasma treatments. The impact of nitrogen and oxygen plasma treatment on polypropylene surfaces was comprehensively evaluated, considering performance properties across all characterization processes.

Leather waste as a filler of synthetic fibers: a novel approach to waste recycling

Leather finished scrap (LFS) is a footwear industrial waste that is often dumped in landfills. Due to environmental problems, there has recently been an increase in interest in using wastes as inclusion for blending materials. The micro leather fibers (MLF) were extracted from the LFS with the help of using fiber isolation machine. This study examines the possibility of using LFS waste as a blending in a polypropylene fiber (PPF). 500 wt % of MLF and different concentrations of PPF (100, 200, and 300 wt %) were used to develop the web fibrous matrix (WFM) by the method of web formation, and injection molded techniques, for their consumer application. The impact of PPF blending concentration on the mechanical characteristics of WFM was assessed. WFM containing up to 300 wt % PPF increased tensile strength (85.95+1.81 MPa), elongation at break (81.18+0.23 %), tearing strength (22.69+0.23 N/mm), flexing index (10.55+0.73 %), etc., characteristics attaining mechanical properties comparable to non-woven polypropylene composite. A biodegradation study was carried out using an enzymatic method, and the results demonstrated the biodegradable properties. The WFM demonstrated desirable applications such as house interiors, shoe lining materials, carpets, puppets, etc., as well as low-cost materials and prevention of pollution.

Characterizing eco-composite boards with non-woven polypropylene from disposable face masks and bamboo reinforcement

This study investigates the development of eco-composite panels using treated and untreated nonwoven polypropylene (PP) extracted from disposable medical face masks, reinforced with bamboo particles. Treated PP underwent a washing process with detergent. Panels were fabricated with varying PP-to-bamboo particle ratios of 100:0, 75:25, and 50:50. Fourier-transform infrared (FT-IR) spectroscopy analysis indicated minimal impact of washing on the intrinsic properties of the PP material, as confirmed by thermogravimetric analysis (TGA). Both analyses showed similar intensities of functional groups and thermal trends in treated and untreated recycled PP (rPP) samples. Energy-dispersive X-ray spectroscopy (EDX) confirmed the uniform integration of bamboo particles within the PP matrix by detecting silicon and potassium elements. Chemical interactions between bamboo fibres and the PP matrix were also evident in the form of reduced peak intensities in FT-IR spectra. Despite these interactions, limited adhesion between bamboo fibres and the PP matrix led to reduced stability and mechanical strength in the eco-composite panels. A direct correlation was observed between board thickness and the proportion of bamboo particles, with the 50:50 formulation showing the greatest thickness. Conversely, board strength decreased as bamboo particle concentration increased due to weak interfacial adhesion. Notably, panels made from treated rPP exhibited superior mechanical properties compared to those from untreated rPP, achieving a modulus of rupture (MOR) of 36.259 MPa and a modulus of elasticity (MOE) of 2048.215 MPa. These findings underscore the potential of utilizing nonwoven PP from disposable medical face masks, reinforced with bamboo fibre particles, to create eco-composite materials with enhanced sustainability and mechanical properties.

Paper fiber-reinforced polypropylene composites from nonwoven preforms: A study on compression molding optimization from a manufacturing perspective

This work optimizes compression molding manufacturing for wet-formed nonwoven paper and polypropylene fiber mats. A central composite designed experiment investigated the effects of fiber reinforcement concentration, compression molding temperature, pressure, and time on composite laminate performance. We assess the composites’ density, panel thickness, water uptake, flexural behavior, and Izod impact strength. Models predicted and optimized composite performance using objective function analysis with penalties applied for undesirable conditions, such as processing time or low reinforcement concentration. Paper fiber content has the largest impact on composite properties, followed by processing time, molding pressure, and temperature. Composite optimization depends on penalty conditions; low fiber content penalties favor low fiber content panels with short processing times, while high fiber content penalties favor high fiber content panels with long processing times. This work suggests that molding composites with a greater fraction of renewable feedstock requires a commensurate increase in processing intensity.

Facile dip-coating of silk fibroin/tannic acid@CaCO3 hybrid film with superhydrophilicity on the surface of polypropylene nonwovens for oil–water separation

Superhydrophilic membrane materials are widely used for oil/water separation due to their excellent resistance to anti-fouling underwater. The key factors for realizing superhydrophilicity of membranes are the introduction of hydrophilic groups and the construction of surface micro/nano roughness structures. Herein, we propose a simple, mild, and green dip-coating method to prepare silk fibroin (SF)-tannic acid (TA)@CaCO3 hybrid film to achieve superhydrophilicity of polypropylene nonwovens (PP). Specifically, the hydrophobic interactions between SF and hydrophobic materials were used to create the pre-coatings. TA molecules were deposited onto the surface of SF via hydrogen bonding to provide phenolic hydroxyl groups for achieving the hydrophilicity of PP membranes. Then, the CaCO3 was synthesized in situ by introducing Ca2+ into the pre-coating while depositing TA to construct micro/nano-roughness structures on the PP membrane surface for obtaining superhydrophilicity. PP-SF-TA@CaCO3 membranes exhibit outstanding superhydrophilicity and underwater superoleophobicity, with separation efficiencies exceeding 99 % for a variety of oil–water mixtures and oil-in-water emulsions, and water fluxes ranging from 4000 L m-2h−1 to 5500 L m-2h−1. The separation efficiencies remained above 99 % throughout 50 separation cycles, indicating the excellent separation stability of the modified membranes. Moreover, no significant loss of separation efficiency was observed when separating oil mixtures from harsh water sources, including acidic, alkaline, cold, and hot water. Therefore, the membranes modified by the above process have a promising application in the practical separation of oily wastewater.

Evaluating the feasibility of direct contact membrane distillation and nanofiltration in ground water treatment through a techno-economic analysis

This study delves into the realm of water treatment by conducting a comprehensive techno-economic evaluation of direct contact membrane distillation (DCMD) and nanofiltration (NF) processes. While previous research has explored the technical aspects of membrane distillation (MD) and nanofiltration, there remains a notable gap in economic analyses. Our research aims to bridge this gap by assessing the financial feasibility of employing MD and NF technologies for water desalination. Specifically, we scrutinize the performance of hydrophobic microporous flat sheet membranes crafted from polytetrafluoroethylene (PTFE) supported by non-woven polypropylene (PP) in desalinating brackish water through DCMD and NF processes. By varying operating conditions such as flow rate and feed temperature, we evaluate the membrane's efficacy. Employing an analytical model based on heat and mass transfer equations, we predict process performance across diverse scenarios. Our model demonstrates a high level of accuracy, with flux predictions deviating by less than 10% when utilizing the Knudsen-molecular mechanism model. Furthermore, through a detailed design and economic analysis of industrial-scale units for both processes, we reveal that the cost of permeated water is lower with NF compared to DCMD. Specifically, our calculations indicate a water cost of 1.34 USD/m3 for DCMD at a feed temperature of 65 °C with an 80% recovery rate, positioning it as a competitive option among conventional desalination methods. Notably, our financial assessment highlights that steam cost constitutes the primary expense in DCMD operations, contingent upon heating value and fuel prices. Noteworthy findings suggest that natural gas emerges as the most cost-effective fuel for steam production in a DCMD plant. This study underscores the economic viability and potential cost efficiencies associated with NF over DCMD in water treatment applications.

Are Geotextiles Silent Contributors of Ultrashort Chain PFASs to the Environment?

We investigated the presence of per- and poly fluoroalkyl substances (PFASs) in woven and nonwoven polypropylene geotextiles and four nonwoven polyester geotextiles commonly used in modern geosynthetic composite lining systems for waste containment facilities such as landfills. Targeted analysis for 23 environmentally significant PFAS molecules and methods for examining "PFAS total" concentrations were utilized to assess their occurrence in geotextiles. This analysis showed that most geotextile specimens evaluated in the current investigation contained the ultrashort chain PFAS compound pentafluoropropionic acid (PFPrA). While the concentrations ranged from nondetectable to 10.84 μg/g, the average measured concentrations of PFPrA were higher in polypropylene than in polyester geotextiles. "PFAS total" parameters comprising total fluorine (TF) and total oxidizable precursors (TOPs) indicate that no significant precursor mass nor untargeted intermediates were present in geotextiles. Therefore, this study identified geotextiles as a possible source of ultrashort PFASs in engineered lined waste containment facilities, which may contribute to the overall PFAS total concentrations in leachates or liquors they are in contact with. The findings reported for the first time herein may lead to further implications on the fate and migration of PFASs in geosynthetic composite liners, as previously unidentified concentrations, particularly of ultrashort-chain PFASs, may impact the extent of PFAS migration through and attenuation by constituents of geosynthetic composite liner systems. Given the widespread use of geotextiles in various engineering activities, these findings may have other unknown impacts. The significance of these findings needs to be further elucidated by more extensive studies with larger geotextile sample sizes to allow broader, generalized conclusions to be drawn.

Iron-Based Oxides Anchored on the Catechol/Silane-Coated Polypropylene Nonwoven Fabrics for Effective Removal of Anionic Dyes

Iron-Based Oxides Anchored on the Catechol/Silane-Coated Polypropylene Nonwoven Fabrics for Effective Removal of Anionic Dyes

Experimental study on enhancing electrostatic charging of nonwoven filter media through novel electrode configurations

The COVID-19 pandemic has underscored the urgent need for efficient particle filtration to tackle public health challenges. This study compares the electrostatic charging capabilities of two types of electrodes: conventional Metal Lamellar Electrodes (MLE) and Modified Lamellar Plate Electrodes (MLPE) with PMMA insulation, in their role of charging nonwoven polypropylene filter media. Experimental analysis unequivocally demonstrates the superiority of MLPE in promoting effective electrostatic charge, as influenced by applied high voltage and inter-electrode distance, resulting in a significant enhancement in fine particle filtration. Numerical simulations of the electric field conducted using the COMSOL software and employing the Finite Element Method (FEM) validate these findings. FEM discretizes the domain into small finite elements and applies Laplace's equation in charge-free regions, providing a comprehensive understanding of the behavior of dual-electrode corona discharge systems. These simulations indicate higher field intensities for MLPE compared to MLE.By integrating experimental and numerical analyses, this study sheds light on the potential benefits of MLPE for air filtration systems, offering a noteworthy advancement in the control of airborne infections and reduction of environmental health risks. This research lays the groundwork for the development of more efficient and durable filtration systems, meeting the increasing demands for public health protection.The findings of this study suggest that the adoption of MLPE could significantly contribute to improving indoor air quality and mitigating the transmission of respiratory diseases. MLPE may also find utility in industrial filtration and air purification in sensitive work environments. Ultimately, this research sets the stage for the development of more efficient and sustainable filtration systems, addressing the growing needs for public health protection.

Wearable T – Shaped Metamaterial Microstrip Patch Antenna with Split Ring Resonators for Wi-Fi Applications

This paper presents the design of a T-shaped metamaterial microstrip patch antenna integrated with split ring resonators, tailored for IEEE 802.11a Wi-Fi applications. The antenna utilizes a non-woven polypropylene geotextile substrate, measuring 1.9 mm thick with a dielectric constant of 2.2, while the copper sheet thickness is 0.1 mm. Performance metrics such as reflection coefficient, antenna gain, and VSWR are evaluated. Simulated results show a reflection coefficient of -21 dB at 5 GHz, which closely matches the measured value of -22 dB. VSWR values of 1.5 and 1.3 are obtained through simulation and measurement respectively. Additionally, SAR analysis indicates suitability for wearable applications, with the SAR value exceeding 10 grams of tissue falling within acceptable limits.

Flexible carbon fiber membrane derived from polypropylene for symmetric quasi-solid-state supercapacitors

The high-value recycling of disposable masks (DMMs) for energy storage applications is an effective way to deal with the overcapacity of waste plastics. In this work, we focus on developing a novel approach for flexible carbon fiber membrane electrodes that utilizes polypropylene nonwoven derived from DDMs. Herein, polypropylene nonwoven is transformed into flexible carbon fiber membrane (CPPK) via sulfuric acid sulfonation, potassium hydroxide (KOH) solution impregnation, and high-temperature carbonization. The KOH solution impregnation activation method offers distinct advantages over the traditional blending process by enhancing the uniformity of the pore structure, thereby improving the flexibility of CPPK. As a result, the as prepared CPPK shows no structural failure even after undergoing approximately one hundred times folds with nearly 180°. Furthermore, CPPK electrodes demonstrate a high specific capacitance of 194 F g−1 at 0.5 A g−1. Besides, symmetric quasi-solid-state supercapacitors (SSCs) comprised with CPPK deliver a great energy density of 10.50 Wh·kg−1 at a power density of 200 W kg−1, as well as excellent bending stability. This study provides a new perspective on developing flexible carbon materials derived from polypropylene nonwoven whether from the point of view of recycling waste plastics or mass production of industry.

Styrene-ethylene-butylene-styrene (SEBS) melt-blown fibers for oil spill remediation and oil barrier geotextiles

The distinctive oil gelation characteristics of styrene-ethylene-butylene-styrene (SEBS) thermoplastic elastomers were utilized for successful oil spill remediation with a range of different oils. Porous non-woven SEBS mat was fabricated via melt blown processing using a twin-screw extruder with customized blow die. After conducting rotational and capillary rheology investigations, a heightened melt-blowing temperature (300 °C) was applied to achieve an elevated melt flow index of SEBS for the melt-blowing process. Under optimized blowing parameters, a non-woven fabric was obtained consisting of fine fibers featuring an average fiber diameter of 20 μm. The material and oil absorption properties of the engineered SEBS fabric were compared to polypropylene (PP) nonwovens, a widely used material for oil spill mitigation that relies solely on adsorption and capillary forces to separate and immobilize spilled oil. SEBS nonwovens exhibited outstanding absorption and gelation properties for both crude petroleum and mineral transformer oil. Notably, SEBS demonstrated the ability to immobilize oil even under head pressure and at saturation, surpassing the capabilities of PP nonwovens (average fiber diameter 12 μm). This showcases a more efficient and cleaner method for remediating oil spills by effectively separating oil from water through absorption.

Fabrication of pore-filling cation-exchange membrane from waste polystyrene and Spunbond Meltblown Spunbond (SMS) non-woven polypropylene fabric as the substrate

Commercial ion-exchange membranes are typically thick, possessing limited mechanical strength, and have relatively high fabrication costs. In this study, we utilize a three-layer polypropylene fabric known as Spunbond Meltblown Spunbond (SMS) as the substrate. This choice ensures that the resulting membrane exhibits high strength and low thickness. SMS substrates with various area densities, including 14.5, 15, 17, 20, 25, and 30 g/m2, were coated with different concentrations of waste polystyrene solution (ranging from 5 × 104 to 9 × 104 mg/l) before undergoing sulfonation using concentrated sulfuric acid. The physicochemical and mechanical properties of the membrane were characterized and compared with those of commercial Neosepta CMX and Nafion-117 cation-exchange membranes. Remarkably, the fabricated membrane exhibited good performance compared to commercial ones. The cation-exchange capacity (2.76 meq/g) and tensile strength (37.15 MPa) were higher, and the electrical resistance (3.603Ω) and the thickness (130 μm) were lower than the commercial membranes.

Plasma-induced Polymerization and Grafting of Acrylic Acid on the Polypropylene Nonwoven Fabric Using Pulsed Underwater Diaphragm Electrical Discharge

Polypropylene (PP) nonwovens are used in many hygiene, healthcare and medical products due to their low cost, high chemical resistance and inertness. From an economic point of view, PP textiles would be used as an excellent support material in regenerative medicine or tissue engineering, but here surface functionalization is necessary to ensure cell adhesion and proliferation. Acrylic acid (AAc) is an excellent source of carboxylic-rich (-COOH) coatings suitable for this purpose, but their multistep preparation is time-consuming. Plasma polymerization provides an excellent solution to this demanding procedure since the process of polymerization and grafting to the substrate takes place simultaneously. Here, we propose a relatively fast and effective method for AAc plasma polymerization by using a pulsed underwater diaphragm electrical discharge operated in an aqueous solution consisting of AAc. AAc layers are successfully grafted onto PP nonwovens, which are continuously rewound through the slit where the plasma is generated. The presence of plasma polymerized AAc layer in the fibrous structure of PP nonwoven was monitored by SEM, FTIR and XPS measurements. Additionally, the improved wettability and adhesion characteristics were investigated by the critical wetting surface tension (CWST) method, the standard method of strike-through time (STT) and „tape-peel“ test. Resulting AAc modified PP nonwoven possesses hydrophilic character, enhanced adhesion and a considerable amount of -COOH groups on the surface. Although after the washing test the FTIR and XPS results indicated a lower concentration of the carboxylic groups, the CWST and STT measurements confirmed the stable hydrophilic character of the PP nonwovens surface.

Green and efficient radiation-based preparation of crosslinked poly(vinyl pyrrolidone)-iodine (PVP-I)-introduced polypropylene (PP) sheets for antibacterial wound dressing application

In this study, we developed an efficient method to prepare a crosslinked poly(vinyl pyrrolidone)/poly(ethylene glycol) diacrylate) (PVP/PEGDA) copolymer-grafted non-woven polypropylene (PP) sheet for which water can be used as a green solvent while providing a large amount of grafting functional groups on the PP matrix without diminishing mechanical properties. It was demonstrated that subsequent iodine complexation of the PP-g-PVP/PEGDA produces a strong antibacterial activity desirable for wound dressings. Efficient functionalization of hydrophobic non-woven PP sheet was achieved using electron beam (EB)-induced graft polymerization of vinyl pyrrolidone (VP) with the addition of hydrophilic crosslinker (PEGDA), resulting in the PP-g-PVP/PEGDA. In this preparation method, the grafting degree was remarkably increased up to 3-fold, even in the water solvent, and was found to be controlled by the concentration of VP and PEGDA. To impart antibacterial activity, the PP-g-PVP/PEGDA subsequently underwent iodine complexation, yielding PP-g-PVP/PEGDA-I. Structural analysis and water absorptivity studies confirmed that excellent water-absorbing PVP/PEGDA-I complexes were successfully introduced in the non-woven PP sheet without significant change in the porous structure of the PP sheet. Moreover, the PP-g-PVP/PEGDA-I exhibited strong antibacterial activities against Gram-negative E. coli, Gram-positive S. aureus, and MRSA bacterial species in a time-killing assay, and the activities showed high dependence on the grafting degree. This finding demonstrates that the PP-g-PVP/PEGDA-I can effectively and immediately inactivate external bacteria upon invasion. This green and efficient strategy is thus promising to produce PVP-I complex-based wound dressings with rapid antibacterial activity.

Polypropylene-Rendered Antiviral by Three-Dimensionally Surface-Grafted Poly(N-benzyl-4-vinylpyridinium bromide).

To inhibit viral infection, it is necessary for the surface of polypropylene (PP), a polymer of significant industrial relevance, to possess biocidal properties. However, due to its low surface energy, PP weakly interacts with other organic molecules. The biocidal effects of quaternary ammonium compounds (QACs) have inspired the development of nonwoven PP fibers with surface-bound quaternary ammonium (QA). Despite this advancement, there is limited knowledge regarding the durability of these coatings against scratching and abrasion. It is hypothesized that the durability could be improved if the thickness of the coating layer were controlled and increased. We herein functionalized PP with three-dimensionally surface-grafted poly(N-benzyl-4-vinylpyridinium bromide) (PBVP) by a simple and rapid method involving graft polymerization and benzylation and examined the influence of different factors on the antiviral effect of the resulting plastic by using a plaque assay. The thickness of the PBVP coating, surface roughness, and amount of QACs, which jointly determine biocidal activity, could be controlled by adjusting the duration and intensity of the ultraviolet irradiation used for grafting. The best-performing sample reduced the viral infection titer of an enveloped model virus (bacteriophage ϕ6) by approximately 5 orders of magnitude after 60 min of contact and retained its antiviral activity after surface polishing-simulated scratching and abrasion, which indicated the localization of QACs across the coating interior. Our method may expand the scope of application to resin plates as well as fibers of PP. Given that the developed approach is not limited to PP and may be applied to other low-surface-energy olefinic polymers such as polyethylene and polybutene, our work paves the way for the fabrication of a wide range of biocidal surfaces for use in diverse environments, helping to prevent viral infection.

Antimicrobial Personal Protection Clothing: Development of Visible Light Activated Antimicrobial Coatings for Nonwoven Polypropylene Fibers

AbstractDuring the COVID‐19 pandemic, the use of polypropylene fleece‐based personal protection equipment (PPE) increased significantly to over ten million tons. Typically, most PPEs are discarded after a single use, to prevent self‐infection of users and spread of infectious agents. However, in order to minimize plastic waste without compromising the protective properties of PPE, it is crucial to explore new reusable or longer‐lived materials. Here, a visible light‐activatable antimicrobial photodynamic dye coating for PPEs is presented. In this context, coating with thiomorpholino‐methylene blue (TMB), derived from methylene blue by introducing two thiomorpholine units, is found to show high antibacterial activity. TMB is integrated into rotary printing suspension, a commercial nitrocellulose‐based printing matrix. The concentration of TMB in adhesive is optimized, and found that 5% TMB is suitable for coating PPE, for reducing the number of Gram‐positive and ‐negative bacteria by 99.99% after 6 h of white light irradiation. Bacterial filtration efficiency and breathability tested according to EN 14683, confirmed that TMB coating does not affect the filter performance. Thus, this antimicrobial photodynamic dye coating technique offers a promising solution for a safer and extended use of PPE, and reduction of plastic waste generated by PPEs.

Superwetting Polypropylene Nonwoven Fabrics Modified by a Catechol-Based Biomimetic Strategy for Oil/Water Separation

Superwetting Polypropylene Nonwoven Fabrics Modified by a Catechol-Based Biomimetic Strategy for Oil/Water Separation