Polymer Bulletin最新文献

This study focuses on the development and characterization of polyurethane coatings using castor oil as a renewable source. Most castor oil-based polyurethane paints have a rather long curing process. Therefore, this study focused on the preparation of a polyurethane paint based on raw castor oil without the need for chemical modifications, in a quick and cost-effective manner. The methodology involved the preparation of the paint using castor oil, isocyanate, calcium carbonate, titanium dioxide, additives and solvents. The coatings were then characterized and compared with industrial polyurethane paint in terms of thermal properties, rheology, UV degradation, adhesion, water resistance, and resistance to salt spray corrosion. Results showed that the castor oil-based paint exhibited comparable rheological behavior to the commercial paint, with superior thermal stability. However, the industrial paint showed better performance in UV degradation and similar behavior in the adhesion tests. In the water resistance test, the castor oil-based paint proved to be superior to the commercial paint. The salt spray corrosion test revealed that the castor oil-based paint had superior corrosion resistance due to the higher proportion of castor oil in the formulation, which increases the crosslinking of the chains. This work offers a simple and fast method to prepare and substitute petrochemical polyols with castor oil in order to use renewable sources with promising properties.

Poria cocos polysaccharide (PCP-C) is a type of fungal polysaccharide, which is an important ingredient in the pharmacological activity of Poria cocos. It possesses significant biological properties like immunological modulation, anti-inflammatory, anti-cancer, and antioxidant. This review summarized the chemical modification and biological activity of PCP-C.

The current study utilized a green synthesis where microwave-assisted free radical technique was applied for economical synthesis of a novel biocompatible polymethyl methacrylate grafted moringa gum amphiphilic graft copolymer, focusing on optimization based on percentage yield, percentage grafting, and intrinsic viscosity was performed, and analytical characterizations confirmed successful grafting. The copolymer demonstrated surfactant-like properties, as evidenced by the determined critical micelle concentration (CMC). Evaluation of its impact on poorly water-soluble drugs, simvastatin, and metronidazole benzoate, revealed efficient release within 60 min. Safety assessments, including In vitro assessments like hemocompatibility, bactericidal activity, fish toxicity, and in vivo evaluations such as oral toxicity, and wound repair studies and cell toxicity studies indicated the safety profile of prepared graft copolymer and explored its potential as a biopolymer for pharmaceutical delivery and tissue regrowth platform.

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The statistical optimization of process parameters using eco-friendly methods to utilize industrial waste for optimal bacterial cellulose (BC) production has yet to be explored. This study adopts a sustainable approach to optimize the biosynthesis of BC production parameters using response surface methodology. A Box-Behnken Experimental Design with three independent variables, such as incubation temperature, medium shaking frequency, and pH of the nitrogen source, was employed to prepare 17 samples of BC from traditional carbon sources (D-Glucose) and low-cost carbon sources such as molasses and beehive extract, which are byproducts of the food industry. The purity and presence of cellulose in the BC were characterized by chemical solubility tests and Fourier transform infrared spectroscopy analysis. The physical and crystalline morphology of the BC was characterized by scanning electron microscopy and X-ray diffractometry. The thermal stability and molar mass (m/z) of BC were analyzed using thermogravimetric analysis and MALDI-TOF mass spectrometry. The influence of process parameters on BC production yields was recorded as 6 g/L in glucose medium, 9.5 g/L in beehive extract medium, and 11.7 g/L in molasses medium under the optimized conditions of 29.08 °C incubation temperature, 126.98 rpm shaking frequency, and pH 5.68. The estimated total costs for BC production were $175/kg from the glucose-based medium, $85.08/kg from the molasses-based medium and $105.26/kg from the beehive extract-based medium. This study aimed to establish optimal conditions for producing comparatively cheap and cost-effective BC for biomedical applications.

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We present a novel 3D nanocomposite aerogel that combines the benefits of polyethylene glycol (PEG), sodium alginate (SA) and zinc oxide nanoparticles (ZnO NPs). PEG serves as the primary component of the aerogel, while SA acts as a filler to enhance its mechanical properties. Both PEG and SA contribute to the aerogel’s adsorption capabilities, while the incorporation of ZnO NPs enhances its antibacterial properties. The ZnO NPs were synthesized using a green method with the assistance of Atriplex halimus (A. halimus) extract. The biosynthesized ZnO NPs were added to a mixture of PEG and SA, and the resulting mixture was subjected to freeze-drying to obtain a porous aerogel beads with a distinctive 3D microstructure. The aerogel composite exhibited a highly porous and sheet-like surface as indicated by scanning electron microscope (SEM). Also, the physicochemical properties of the PEG/SA/ ZnO NPs aerogels composite were estimated such as crystallinity, chemical structure and optical properties. The PEG/SA/ZnO NPs aerogels beads exhibited a swelling rate exceeding 200%. The MIC of the ZnO NPs against E. coli, A. baumannii, K. pneumonia, P. aeruginosa, S. aureus and S. epidermidis were 12.5, 12.5, 25, 25, 6.25 and 6.25 U/ml, respectively. The aerogel demonstrated remarkable antibacterial activities, as evidenced by inhibition zones ranging between 15 and 22 mm² against multidrug-resistant bacteria (MDR). Moreover, the aerogels exhibited significant inhibition efficacy on the MDR bacterial growth with complete inhibition for all strains. These findings highlight the highly effective bactericidal properties of the aerogels. The cytotoxicity of both ZnO NPs and PEG/SA/ZnO NPs was evaluated using HeLa cell lines. The results showed that the ZnO NPs and PEG/SA/ZnO NPs exhibited reasonable anticancer activity against this cell line. The newly developed 3D composite PEG/SA/ZnO NPs aerogels exhibits broad-spectrum antibacterial capabilities against MDR bacterial strains for medical and pharmaceutical applications.

This research delves into the comprehensive assessment of a novel composite material, comprising Himalayan nettle fibre (HNF) and vinyl ester resin, reinforced with silicon-rich siliceous rock dust (SRD). The purpose of this study is to develop an eco-friendly composite material for various engineering applications. The HNF was used in chopped form, and the composites were prepared via hand layup process. Results of these composites revealed that the inclusion of SRD led to a significant enhancement in wear resistance with reduced sp. wear rate of 0.009 mm³/Nm and coefficient of friction of 0.22, indicating material’s resistance to wear. Similarly, flammability characteristics were rigorously examined through standard tests. The introduction of siliceous rock dust induced a substantial improvement in fire resistance, as evidenced in VN3 (HNF 40 vol.% and SRD 5 vol.%) composite by reduced flame propagation speed of 4.11 mm/min with HB and V-0 UL-94 ratings. Similarly, the composite’s thermal stability was increased with the incorporation of SRD. Composite VN3 (HNF 40 vol.% and SRD 5 vol.%) observed with high initial degradation temperature of 387 °C, respectively. The findings of this study are significant, showcasing the positive impact of silicon-rich siliceous rock dust on the dry sliding wear resistance, flammability and thermal stability of the composite. This innovative material has the potential to revolutionize industries where mechanical performance and fire resistance are of concern, including but not limited to construction, transportation, and aerospace.

In this contribution, we report the investigation on removing of the oxochromium (VI), a hazardous species, using HCl-doped polyaniline (PAni-HCl) as adsorbent versus particles size. PAni-HCl has been successfully elaborated by conventional oxidative chemical method in the temperature range (0–3 °C). The recovered powder was milled and sieved into size ranges of < 50, 50–63, 125–160 and > 200 µm. The batch adsorption experiments were performed at 25 °C, using 250 mg of PAni-HCl dispersed in 250 mL of Cr(VI) aqueous solution (250 mg L⁻¹). The Cr(VI) uptake was significantly influenced by both the particle size and contact time. Smaller particle sizes allow a quick initial adsorption and high removal efficiency (~100%). The kinetics of the Cr(VI) adsorption follow the pseudo-second-order model. A good correlation was demonstrated between the removal chromium (VI) properties (Q_e,exp, k₂ and τ(%)) and the (normalized) mean diameter ratio.

Plants are mainly considered as the important source of energy and from ancient times plants, and the plants products are used in various form. These pharmacologically bioactive compounds have limited use due to their insolubility in water, and to overcome this, these compounds were encapsulated in biodegradable polymers and gums which enable them to be used practically for therapeutic purposes. In this review article we briefly discussed about the trans-ferulic acid-loaded polymeric nanoformulations which can be used for preclinical and clinical purpose. Trans-ferulic acid-loaded polymeric nanoformulations were synthesized using ionic gelation method. The polymeric nanoformulations have diameter mainly in nanometers which is mainly due to their high surface area to volume ratio. Their unique physical and chemical properties make them attractive for a variety of applications, such as drug administration, cosmetics, and environmental remediation. Plant science is becoming more and more interested in the topic of nanotechnology, particularly with regard to the use of nanomaterials as vehicles for agrochemicals or biomolecules and their enormous potential in different fields. It has been shown in recent years that significant advancements in nanotechnology have been made in the synthesis of nanoparticles and their use in diagnosis and treatment in medicine. More research is deemed necessary in this direction to optimize the synthesis and biofunctionalization of nanoparticles for different applications, as well as to better understand the mechanisms and enhance sustainability for human health. Lastly, we have examined a few cutting-edge and novel ferulic acid nanoformulations and we assume that this review article will provide researchers a chance to close the gaps in preclinical and clinical research.

Mosquito-repellent textiles are classified as protective textiles designed to mitigate the presence of mosquito species recognised as vectors for diseases such as malaria and dengue fever. This study aimed to explore the feasibility of employing a nanoemulsion system containing lemongrass essential oil encapsulated with biopolymers, specifically tragacanth gum and cationic guar gum, as finishing materials on cotton and polyester fabrics. Being anionic biopolymer, tragacanth gum has resulted in outstanding zeta potential, polydispersity index, particle size and encapsulation efficiency with the values of − 38.1 mV, 0.2, 14.1 nm and 99%, respectively. The positively charged guar gum that interacted with aluminium chloride led to precipitation, which disfavoured retention and repellency properties. Based on correlation coefficient (R²) values for tragacanth gum (0.9832) and cationic guar gum (0.9761)-based nanoemulsions, the release of lemongrass essential oil from nanoemulsions followed the Korsmeyer–Peppas kinetic model. Following five cycles of washing and heating, the retention of tragacanth gum-based nanoemulsion on cotton and polyester was determined as 62% and 46%, respectively. From an Excito chamber study, 64% of Aedes aegypti were successfully repelled from nanoemulsion-treated cotton, whereas 53% of the same mosquito species were repelled from nanoemulsion-treated polyester. Overall, results from this study are in line with the mosquito vector control initiative outlined by the World Health Organization.

In the current study, a porous composite material, hydroxyapatite/chitosan/microcrystalline-cellulose (CaHAp–CS–MCC), was successfully prepared and used for the adsorption of Eriochrome Black T (EBT) from water. X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), differential thermal analysis (DTA), thermogravimetric analysis (TGA), specific surface area (SSA), and atomic force microscope (AFM) were used to evaluate the physicochemical properties of the prepared adsorbents. CaHAp–CS–MCC exhibited a decrease in crystallinity and reduction in crystallite size. CaHAp–CS–MCC surface exhibited cracks and pores. AFM displayed changes in surface micro-texture of CaHAp, formation of new surface structures, and variations in particle size and distribution. Upon grafting CaHAp with CS and MCC, its specific surface area decreased from 139.224 to 11.775 m²/g. BET suggested that filling CaHAp pores by CS and MCC contributed to the reduction in surface area. The pore volume values decreased from 2.56 × 10^–1 (CaHAp) to 3.91 × 10^–2 cm³/g (CaHAp–CS–MCC). Adsorption equilibrium was reached at about 40 min. The adsorption capacities values of CaHAp–CS–MCC and CaHAp were equal to 248 mg/g and 92 mg/g, respectively. The pseudo-second order and the Langmuir equations fitted well the adsorption phenomenon. The calculated thermodynamic parameters showed an exothermic and non-spontaneous system.