Advances in Polymer Technology最新文献

Since polymer nanocomposites provide a versatile method to improve safety and protection in various applications, they are essential in tackling the problem of microbial infections. These nanocomposites are designed to actively prevent the growth of bacteria by including antimicrobial agents such as functional groups or nanoparticles. In the present article, copper oxide nanoparticles were synthesized via the green method using the solution method. The grafting of N-ethyl piperazine (NEP) to polyvinyl chloride (PVC) polymer was carried out to obtain NEP–PVC polymer using solution polymerization technique and further reacted with CuO nanoparticles to obtain polymernanocomposite which was characterized using FTIR and ¹H-NMR, SEM, TEM, DLS, and XRD. The comparison in the antibacterial activity of nanocomposite and the synthesized polymer was carried out to determine its efficacy against Escherichia coli and Staphylococcus aureus using the spread plate method. Our findings indicate that NEP–PVC-based nanocomposite after incorporating copper oxide nanoparticles has enhanced the antibacterial properties over NEP–PVC polymer, henceforth a promising candidate to be used in medical devices, food packaging, and surface coatings.

The aim of this work is a synthesis of suitable hydrogel to produce slow-release fertilizer using recycled cellulose which is obtained from waste paper. For this purpose, initially, we extracted alpha cellulose from waste paper and modified it to obtain carboxymethyl cellulose (CMC). Then, the CMC was converted to a suitable hydrogel through in situ graft copolymerization of acrylic acid and vinyl acetate in the presence of methylene bisacrylamide as a crosslinker. The various factors that affect hydrogel synthesis, such as the amounts of CMC, monomers, initiator, and crosslinker, were evaluated. In the optimized formulation, the weight ratio of monomers to CMC is 7, the molar ratio of monomers to each other is 1, and the crosslinker is used as 3 molar percent of monomers. The products were characterized using Fourier transform infrared, thermal gravimetric analysis, and scanning electron microscope analyses. The swelling behavior of the synthesized hydrogels was evaluated in different environments, such as distilled water, tap water, salt water, and different pH levels. The swelling ratio increases with an increase in pH level. Between the synthesized hydrogels, the best one was selected for slow-release fertilizer production and loaded with 20-20-20 fertilizer (NPK), and the release behavior was evaluated. In an alkaline pH, there was a long time for NPK release within a slow-release medium and even after 361 h, the release process was continued. Also, the performance of the fertilizer-loaded hydrogel in soil using water holding capacity and water retention ratio tests were evaluated.

Due to cross-linked structures, thermoset polymers cannot provide sufficient free volume for nanofillers to maneuver. Related composites are therefore governed by phase separation where filler-deficit regions become mechanical weakness. This work discovers that carbon nanotubes can be redispersed in thermoset polymer through heat treatments, thus, enhancing strength, thermal, and electrical conductivity of composites. Experiments carried out on a different thermoset matrix gives a similar trend where heating induced tube displacement is also verified by molecular dynamic simulations and piezo-resistivity tests.

To improve the electrical conductivity, mechanical properties, and antibacterial properties of conventional hydrogels while simplifying their preparation steps for better application in wearable, flexible sensors and biomimetic electronic skins. Polyvinyl alcohol (PVA) hydrogels were doped with an ionic liquid based on zinc chloride to synthesize improved hydrogels using the freeze-thawing method. It is found that the addition of ionic liquid based on zinc chloride to the hydrogel resulted in a significant increase in electrical conductivity. However, an excessive amount of these liquids led to a reduction in their mechanical properties. The results reveal that the balance between conductivity and mechanical properties can be achieved by controlling the concentration of the ionic liquid based on zinc chloride. The higher the ionic liquid concentration based on zinc chloride in the composite hydrogels, the better the conductivity performance. The addition of an ionic liquid based on zinc chloride resulted in a significant improvement in the conductivity performance of the hydrogels. Furthermore, excellent mechanical properties are maintained even at a mass ratio of 1 : 10 between ionic liquids based on zinc chloride and PVA hydrogels, and composite hydrogels exhibit excellent antibacterial properties.

This study aims to convert cotton-based post-consumer textile waste to biodegradable paper, which not only addresses the discarding of waste but also provides a second use of cotton. The post-consumer garment made with cotton was decolorized by stripping with concentrated NaOH and hydrose. Afterwards, it was chopped, ground, and treated with NaOH solutions. The paper was prepared through a wet-laid process by mixing carboxymethyl cellulose as a binder with chopped cotton textiles. To reduce water absorbency, the uncoated paper was coated with thermoplastic polyurethane (TPU) using heat pressing technique. The surface morphology and chemical structure of uncoated pristine paper, coated paper, and TPU films were conducted using SEM and FTIR studies. The tensile strength, contact angle, air permeability, and biodegradability tests were investigated according to the standard methods. The tensile properties of the papers were increased after TPU coating, accounting well around 28% compared to the uncoated pristine paper. The elongation at the break of the coated paper was at least 40% greater than the uncoated pristine paper. The coated paper displayed a higher water contact angle of 100°, even after 10 min. The lower air permeability was observed in the coated paper due to TPU film blocking the free spaces of the paper. The TPU-coated paper exhibited a weight loss of 48.1%–59.8% after 90 days, whereas the uncoated paper was 100% decomposed after 60 days. The burning of post-consumer cotton textile waste (PCCTW) paper generated ashes resembling those of burning paper, implying clean and environmental friendly biodegradation. The papers can replace the petroleum–plastic materials and serve as food and other packaging applications.

Epoxy polymer composites reinforced with fish scale-derived collagen (EFC) have garnered significant interest due to their potential for enhancing mechanical properties and environmental sustainability. In this study, we investigated the mechanical, thermal, and morphological characteristics of epoxy composites reinforced with varying concentrations of EFC (5%, 10%, 15%, 20%, and 25% wt). Tensile strength testing revealed an initial increase in Young’s modulus with 5% and 10% EFC concentrations, followed by a decrease at higher concentrations, attributed to agglomeration effects. Flexural strength (FS) exhibited a decreasing trend with increasing EFC content, while flexural modulus (FM) showed improvement up to 20% EFC loading. Scanning electron microscopy (SEM) analysis highlighted the distribution of collagen particles, with agglomeration observed at higher concentrations. Fourier-transform infrared spectroscopy (FTIR) spectroscopy indicated alterations in hydrogen bonding with the addition of EFC. Thermal analysis revealed a reduction at onset degradation temperature with EFC incorporation, attributed to poor dispersion and agglomeration effects, alongside a slight enhancement in thermal stability at higher concentrations. The study supports the sustainable use of EFC as a filler, by offering a renewable and eco-friendly alternative to reinforcing polymer composites.

Different samples of Asahi model SB-1000 polymer optical fibers arranged at different curvatures were aged to predict the loss of light transmission over 10 years. They were used in the FV0 detector of the ALICE experiment at the LHC. The fibers were exposed to 80°C, maintaining a relative humidity of less than 50% RH. The relative transmission loss was measured before and after aging. A maximum loss of 15% was found for 632 hr of aging, equivalent to 5 years for the ALICE experiment conditions considering thermal aging. This estimate is based on the Arrhenius model, using energy activation data from the literature. Complementary tests were done to analyze the fiber materials, such as XRD (WAX), FTIR, and mechanical tensile tests. For FTIR, no changes are found that indicate modifications in the chemical structure but in the physical properties of the materials. A study based on XRD shows that during the first 72 hr, changes in crystal size were observed, and consequently, there was a loss of transparency. Hence, mechanical tests indicate that the fiber decreases its Young’s modulus with longer aging times, making the material more tenacious to rupture.

This review provides a comprehensive overview of the multifaceted factors influencing TPE foam production, with a specific focus on the intriguing role of induced crystallization. TPE foams excel in versatility and cost-effectiveness, yet their production faces several challenges, that significantly impact their final characteristics. The examination encompasses a range of factors, including solubility, diffusivity, interfacial tension, rheology, foaming parameters, nucleating agents, and the intricate influence of induced crystallization on TPE foam structure and performance. In TPE, crystallinity can be induced through various means including gas sorption, stress concentration, extrusion, annealing, and self-nucleation. These induced crystals serve as nucleation sites for heterogeneous nucleation during foaming. The advancements achieved in polymer foam are thoroughly evaluated in terms of both progress and limitations, drawing insights from various research findings. Furthermore, the review examines recent developments and explores the effects of induced crystallization on TPE foam.

Numerous studies have examined rattan and date palm fibers separately, but none have combined both fibers in a single composite. This research focuses on creating novel hybrid composites using untreated and treated rattan and date palm fibers. Fibers were treated with 3%, 4%, and 5% NaOH solutions. Fiber diameters were measured microscopically. The NaOH treatment enhanced the tensile strength of the fibers. Untreated rattan, midrib, and spadix stem fibers exhibited tensile strengths of 18, 57, and 37 MPa, respectively. Polyester was used as the matrix, combined with fibers in weight fractions of 70 : 30, 75 : 25, and 80 : 20. All composites were made for 1 : 1 rattan–midrib and 1 : 1 rattan–spadix stem fibers. Composites containing 20% treated rattan–midrib fibers displayed the highest tensile and flexural strengths, measuring 13 and 39 MPa, respectively. Meanwhile, rattan–spadix stem composites achieved the highest tensile strength of 14 MPa at 30% treated fiber loading, and the highest flexural strength of 28.91 MPa at 20% fiber wt.%. Additionally, SEM images of the tensile fracture surfaces revealed voids, cracks, and impurities. The goal was to develop a new composite that provides a low cost, structurally sound, and environmentally friendly strong material suited for industrial, construction, and aviation applications.

The article provides a brief overview of the use of zeolites as environmentally safe anticorrosion pigments for organic coatings on metals. The number of studies on zeolite-based inhibiting pigments has increased significantly in recent years, due to the need to replace chromates and reduce the content of phosphate corrosion inhibitors. Based on the results available in the literature, an assessment was conducted on the inhibitory properties of complex zeolite pigments obtained by various methods. Emphasis is placed on the advantages and disadvantages of ion exchange modification of zeolites with inhibitory substances and mechanochemical synthesis of pigments. Zeolites have a wide perspective in anticorrosion technologies due to their porous structure, large surface area, high pore volume, and the ability to accumulate inhibitory ions and molecules. Such properties of zeolites make possible their use for the development of self-healing or “smart” polymer coatings. Considering the environmental safety of zeolites and their excellent thermal and chemical stability, anti-corrosion polymer coatings inhibited by zeolite pigments could become an effective environmentally friendly alternative to chromate-based protective coatings. The main trends and prospects for the development of research in this domain are presented.