International Journal of Polymer Analysis and Characterization最新文献

Poly (1,4-phenylene ether ether sulfone) (PEES) is a commonly used polymer in membrane technology for water treatment applications such as water purification and blood dialyzing in hemodialysis. In this study, PEES was chemically modified by nitration, yielding nitrated Poly (1,4-phenylene ether ether sulfone) (NPEES). Following that, NPEES nanocomposites (NCs) comprise multi-walled carbon nanotubes (MWCNTs), and the process involved the synthesis of reduced graphene oxide-oxidized single-walled carbon nanotubes, abbreviated as reduced (GO-oxSWCNTs). Various characterization techniques were used on the created membranes, such as Fourier-transform infrared spectroscopy (AT-FTIR), X-ray diffraction (XRD), and scanning electron microscopy (SEM) with energy dispersive X-ray (EDX) analysis. All polymer nanocomposites were found to be amorphous, according to the XRD patterns. SEM scans revealed random crater-like features on the surface of NPEES, but MWCNTs and reduced (GO-oxSWCNTs) NCs were distributed evenly on the polymer surface. The primary goal of this study was to evaluate the antimicrobial activity of modified NPEES membranes against two Gram-positive bacteria, Staphylococcus aureus (S. aureus) and Bacillus subtilis (B. subtilis), two Gram-negative bacteria, Pseudomonas aeruginosa (P. aeruginosa) and Escherichia coli (E. coli), and a fungus, Candida albicans (C. albicans). All modified membranes, including NPEES, NPEES/MWCNTs NCs, and NPEES/MWCNTs/reduced (GO-oxSWCNTs) NCs, exhibited antibacterial activity against S. aureus and B. subtilis. Notably, when compared to NPEES/MWCNTs NCs and NPEES/MWCNTs/reduced (GO-oxSWCNTs) NCs, the NPEES membrane had higher antibacterial activity, generating a 12 mm inhibitory zone. Furthermore, molecular docking studies revealed a strong fit of the tested polymer nanocomposites into the DNA gyrase B active site (PDB ID: 4uro), which was consistent with the practical results of their antibacterial activity evaluation.

In this study, four distinct composite samples (Samples A, B, C, and D) were fabricated using varying compositions of biochar, rice bran, coconut coir, and epoxy matrix. Sample A, serving as the baseline with 90% epoxy and 10% biochar, exhibited moderate mechanical properties. Sample B, with 80% epoxy and 20% biochar, demonstrated significantly higher tensile and flexural modulus values, indicative of improved stiffness. Sample C, incorporating 10% rice bran alongside 80% epoxy and 10% biochar, displayed reduced mechanical properties compared to Sample B, potentially due to the lower strength of rice bran particles. Sample D, comprising 80% epoxy, 10% biochar, and 5% coconut coir, demonstrated weaker tensile properties but higher flexural modulus, suggesting enhanced resistance to bending forces. Mechanical testing, water absorption analysis, Fourier Transform Infrared (FTIR) spectroscopy, and SEM imaging provided comprehensive insights into the mechanical and chemical characteristics of the composites, underscoring their potential for diverse applications in sustainable materials development.

The research aim is to develop pure epoxy composites (PEC), PTL-reinforced epoxy composites (PTLEC), PTL-loaded and E-glass fiber- incorporated epoxy composites (PTLEIEC), and PTL- and E-glass fabric and graphene oxide-incorporated epoxy composites (PTLEIEGO) were fabricated through an open molding hand layup technique, and structural, mechanical, and thermal stability were carried out and results were compared. Functional groups such as OH, -C-H, C=O, C=C, and C-OH, were found in PTL. Similarly, the OH, C-H, Si-O-Si, C=O, and C-H present in the PTLEIEGO composites were found through Fourier transform infrared spectroscopy (FTIR). The crystal plane orientations (110) and (220) in the PTLEIEGO composites were found through XRD. The surface morphology and elemental compositions of PTLEIEGO composites were found through field emissions electron microscopy (FESEM) and found the presence of different organic and inorganic elemental compositions such as C, O, Si, Ca, Zn, K, and Br as 77.85, 20.78, 0.33, 0.45, 0.05, 0.05, and 0.50 wt.% through energy dispersive X-ray (EDX) spectroscopy. The DSC and TGA were carried out and found the thermal stability of the composites and the onset melting temperature was found to 353.1˚ C. The maximum tensile strength of PTL, PEC, PTLEC, PTLEIEC, and PTLEIEGO composites was found to be 1.25 MPa, 25 ± 0.5 MPa, 55 ± 0.5 MPa, 93 ± 0.5 MPa, and 120 ± 0.5 MPa as per ASTM D 638. The tensile strength was improved from 1.25 MPa for PTL to 120 ± 0.5 MPa for PTLEIEGO. The FEM results revealed a minimum error of 0 % and a maximum error of 21.38 % compared to the experimental results. The maximum shore D hardness of PEC, PTLEC, PTLEIEC, and PTLEIEGO composites was found to be 55 ± 0.5 SHN, 59 ± 0.5 SHN, 76.1 ± 0.5 SHN, and 81.4 ± 0.5 SHN, respectively, as per ASTM D2240. The flexural strengths of PEC, PTLEC, PTLEIEC, and PTLEIGO composites were found to be 37 ± 0.5 MPa, 43 ± 0.5 MPa, 94 ± 0.5 MPa, and 131 ± 0.5 MPa, respectively, as per ASTM D 790. The new composites would be employed in low-strength structural applications such as panels, cabins, doors, and laptop stands.Highlights

1. The tensile strength of PTL, PEC, PTLEC, PTLEIEC, and PTLEIEGO were found to be 1.25, 25 ± 0.5, 55 ± 0.5, 93 ± 0.5, and 120 ± 0.5 MPa, respectively.

2. The tensile strength of the experimental results was compared with FEM results.

3. The shore D hardness of PEC, PTLEC, PTLEIEC, and PTLEIGO was determined to be 55 ± 0.5, 59 ± 0.5, 76.1 ± 0.5, and 81. 4 ± 0.5 SHN, respectively.

4. The novel composite would be employed in low-strength structural applications such as panels, cabins, doors, and laptop stands.

This study investigates the impact of the ion beam on the properties of composite PEO/NiO, which was fabricated using the solution casting method and applied in advanced dielectric applications. The samples were exposed to ion beam at different fluencies (5 × 10¹⁶, 10 × 10¹⁶, and 15 × 10¹⁶ ions/cm²) using cold cathode ion source. The structure of the pure and treated PEO/NiO films was studied using the XRD technique, which demonstrated the successful fabrication of the composite PEO/NiO. Moreover, the morphological changes were analyzed by SEM, which indicates the homogeneous distribution of NiO in PEO. Furthermore, the dielectric characteristics of PEO/NiO films were tested at a frequency range of 40–10⁶ Hz. The dielectric constant enhanced from 22.8 for PEO/NiO to 128.5 for the irradiated 15 × 10¹⁶ ions/cm², and the energy density enhanced from 1.1x10⁻⁴ to 5.6x10⁻⁴ J/m³. The results demonstrate that the irradiated PEO/NiO composite exhibits novel dielectric properties, allowing the use of the irradiated PEO/NiO composite in different devices as super-capacitors and batteries.

Starch-based thermoplastic polymer is a biopolymer that is being widely explored as a replacement for conventional polymers. Since thermoplastic starch suffers from mechanical defects, certain mechanical and thermal properties of starch-based polymers can be improved by incorporating fillers or reinforcements derived mainly from natural substances. This article reports the preparation, physicochemical, and mechanical characterization and biodegradation of starch-based bioplastics extracted from potato (Solanum tuberosum) peels using glycerol (G) as plasticizer and reinforced with carob powder, a readily growing plant in Mediterranean climates. The present study investigates the effect of incorporating different proportions (0, 2, 5, 10, and 15 wt.%) of carob powder (Cb) in the films thus prepared. These biopolymer films were fully characterized using analytical techniques including Fourier transform infrared spectroscopy with attenuated total reflection (FTIR/ATR), thermogravimetric analysis (TGA/DTG), X-ray diffraction (XRD), optical microscopy (OM), Scanning electron microscopy (SEM), mechanical evaluations, and biodegradability assessments. The biodegradability of the obtained bioplastic samples was evaluated. Scanning electron microscopy (SEM) revealed strong interfacial adhesion between the constituent filler and the polymer matrix.