International Journal of Polymer Science

This study investigated how the extruder temperature, printing speed, and specimen geometry interact during a tensile test of continuous carbon fiber-reinforced nylon matrix composites produced by the fused deposition modelling (FDM) process. The investigation utilized statistical techniques. For this purpose, tensile examinations were done on manufactured samples using a testing apparatus. The study’s objective is to identify the most efficient specimen geometry for tensile testing result optimization and to maximize the 3D printing process’s capability for producing complex, freeform patterns in these composites. In this study, the input parameters required for the response surface methodology (RSM) were varying extruder temperature (240-255°C) and printing speed (60-80 mm/s), and experimental responses included modulus, elongation at break, and weight. The findings of the regression analysis showed output responses are influenced by both input variables. The results showed that the strength of the samples was significantly influenced by the input parameters. To draw the surface and residual plots, the software of design expert software was used. The interaction between the two input variables suggests raising the extruder temperature and decreasing printing speed, which leads to printing heavier samples. Inversely, the diversity between the forecasted and real responses for the optimal specimens is less than 10% which is assumed to be acceptable for the design of experiments (DOE). The analysis took into account the lower and upper ranges of the input variable with the goal of enhancing both the most modulus and fracture elongation while simultaneously degrading the weight of the specimens. To achieve this objective, the extruder temperature and printing speed are between 240 and 250°C and 65 and 75 mm/s, respectively.

In this study, lemon, and sour cherry seed essential oil-added glycerol and/or sorbitol-plasticized corn, potato, rice, tapioca, and wheat starch-based edible films were produced using the casting method. Starch, essential oil type and glycerol and/or sorbitol effects on the thickness, moisture content, water solubility, swelling index, and water vapor transmission rate of the films have been studied. The interaction of the film components was evaluated by Fourier transform infrared spectroscopy. It was seen that wheat starch-based control films give the lowest thickness value (0.010 mm). Wheat starch-based control films (15.50%), sour cherry seed essential oil-added corn starch (17.80%), and lemon essential oil-added rice starch-based composite films (17.70%) have high moisture content. The lowest solubility values were obtained from wheat starch control (22%) and sour cherry seed essential oil-added corn starch composite (16.40%) films. The highest swelling index values were obtained from wheat starch-based control (210.90-289.0%), sour cherry seed essential oil-added tapioca starch (388.80%), and lemon essential oil-added potato starch-based (433.20%) composite films. Rice starch-based control films have the lowest water vapor transmission rate (). FTIR spectra of edible composite films proved that there is no chemical interaction between the film component and that they kept their structure. The main difference of this study from previous studies was the use of sour cherry seed essential oil for the first time in edible film production and the comparison of the film properties of corn, potato, rice, tapioca, and wheat starch-based edible films plasticized with glycerol or sorbitol.

The objective of this study is to establish a conceptual framework for fiber-reinforced polymer composite (FRPC) panels designed for structural purposes through the incorporation of a third phase (fillers). The present investigation was aimed to design and fabricate 3-phase polymer composite panels that offer enhanced thermal insulation and strength while maintaining low material and labor expenses. Two types of fibrous reinforcements (jute fabric and glass fabric) of different origins were used as reinforcement; polypropylene (PP) was used as the matrix, and microcrystalline cellulose (MCC) was used as particle reinforcement material. The composite materials were fabricated with different MCC concentrations (0, 2 wt%, and 4 wt%), using a hot compression molding technique. It was found that MCC helped to enhance the mechanical performance of the composite panels, while the thermal conductivity showed a slight reduction due to lower concentrations of MCC used. For polypropylene/glass (PPG) composites, thermal conductivity was reduced from 0.214 to 0.193 W/m·K by the addition of 4% MCC fillers. Similarly, for polypropylene/jute (PPJ) composites, it was reduced from 0.14 to 0.126 W/m·K by 4% MCC fillers. The Charpy impact strength of both PPG and PPJ composites was enhanced by the addition of fillers, and the effect was more significant in the case of PPG (increased from 24.83 to 43.98 kJ/m² for 4% fillers). Cost analysis of the composite panels was also done, showing PPJ panels to be slightly cheaper as compared to PPG. The findings indicate that the developed composite panels have the potential to serve as partitioning as well as the outer shield of the building due to their effective thermal and mechanical properties.

In this paper, reduced graphene oxide decorated with silver nanoparticle (rGO-Ag) nanohybrids were prepared using an environmentally friendly approach and incorporated as reinforcement in poly(vinylidene fluoride)-poly(methyl methacrylate) blends via a melt mixing process. The microstructure of rGO-Ag nanohybrids and its effect on the microstructure, mechanical, thermal, and electrical properties of the PVDF/PMM/rGO-Ag was studied using Fourier transform infrared (FTIR), Raman spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), tensile, thermogravimetric analysis (TGA), and impedance spectroscopy methods. FTIR and TEM analysis confirmed that rGO-Ag successfully synthesized and Ag nanoparticles are located on the rGO surface. The tensile analysis demonstrated that incorporating 1 wt.% of rGO-Ag in PVDF/PMMA blend increases Young’s modulus and strength of nanocomposite up to 31% and 35%, respectively. The Halpin-Tsai model was also used for PVDF/PMMA/rGO-Ag nanocomposites, and the results confirmed that this model works well to predict the tensile modulus. Impedance spectroscopy analysis showed that the presence of rGO-Ag nanohybrids in PVDF/PMMA blend effectively enhanced the conductivity of PVDF/PMMA blend. TGA results demonstrated that the presence of rGO-Ag nanohybrids enhanced the thermal stability of nanocomposites and increased the degradation temperature of PVDF/PMMA/rGO-Ag nanocomposites in the range of 20°C compared to PVDF/PMMA blend.

The aim of this study is to determine and quantify the monomer elution from four different resin-based composite dentin replacement materials for 3 months using HPLC. Four different composite dentin replacement materials were used in the present study: EverX (EVX), X-tra base (XTB), SDR (SDR), and GrandioSO Heavy Flow (GHF). Fifteen samples from each material were prepared ( mm). After preparation, each specimen was immersed in a 10 ml 75% ethanol/distilled water solution for three different periods: 1 h, 24 h, and 3 months (). After the immersion period, 0.5 ml of solutions were taken from each bottle and analyzed using HPLC. At the end of the 3-month immersion period, the elution of monomers was determined mostly from SDR, GHF, EVX, and XTB, respectively. TEGDMA, the most released monomer of all groups, was released from all samples after 1 h, 24 h, and 3 months. The amount of monomer released in all composite groups at the end of the 3-month immersion period was significantly higher than the monomer amounts released after the 1-hour immersion period. The monomers were eluted from the composite dentin replacement materials during all immersion periods, and the amount of eluted monomers was increased with time.

Clindamycin phosphate is a topical antibiotic agent used to treat acne vulgaris, while Aloe vera has both antimicrobial and anti-inflammatory properties. The current study is aimed at formulating an antiacne gel with antioxidant and antimicrobial effects. The antiacne gels were prepared by using polymer HPMC K15M by cold dispersion method. Unveiling the intricacies of gel design, our research harnessed the power of Design Expert 11 to optimize critical parameters—viscosity, spreadability, and permeability. In vitro characterization tests, including pH, spreadability, viscosity, permeability, antimicrobial activity, antioxidant activity, and stability of the gels, were performed. The results of in vitro characterization tests showed that the gels had a mint-like odor, a pH of 6.8, and a spreadability of 21.5 g cm/sec. The gels had a viscosity of 34.2 Pa s and drug content ranging within 90%-110%, as per USP standards. Notably, in vitro permeation assays reveal an exceptional 86% drug release, showcasing the efficacy of our formulation. The uniqueness of our study lies not only in the robust optimization process but also in the multifaceted characterization. Our gel emerges as a promising candidate, exhibiting not only desired antimicrobial and antioxidant properties against acne vulgaris but also demonstrating stability under varied conditions. As we advance toward in vivo studies, our research paves the way for a nuanced understanding of the safety and efficacy of this distinctive antiacne gel.