Fire-extinguishing microcapsules, consisting of a shell and a fire-extinguishing core agent, can quickly control fires in early stages. In this study, C6F12O-based fire-extinguishing microcapsules were synthesized through in situ polymerization. How different emulsifiers, shell materials, inorganic additives and drying temperature influenced the yield of both the core substance and the microcapsules were investigated. The most effective emulsifier was poly(ethylene-alt-maleic anhydride) (SMA), whose average molecular mass was 28,000. Moreover, the use of melamine-formaldehyde (MF) resin and inorganic nanosheets negatively affected the yield of the microcapsules. When the samples were dried at 20°C, the core content and yield of the fire-extinguishing microcapsules with urea-formaldehyde (UF) shell were 66.1 and 67.7 wt
Thermogelling Poloxamer 407-based compositions containing delivery systems for the anticancer drug doxorubicin (polypeptide nanoparticles—NP or dextran sulfate coated calcium carbonate submicroparticles—DCC) were developed. These two-level compositions could serve as depots for local chemotherapy after glioma surgery, releasing doxorubicin into the surrounding tissue in sustained release mode. The Poloxamer 407 concentrations were selected to ensure hydrogel formation at body temperature. The interaction between the Poloxamer 407 molecules and both types of delivery systems affected the temperature dependences of composition viscosity; the existence of these interactions was also confirmed by FTIR spectroscopy. The structural characteristics of the compositions and their sustained doxorubicin release profiles into cerebrospinal fluid were established. It was shown that the introduction of delivery systems (based on DCC) into the gel stabilizes the structure of the compositions and enhances their resistance to biological fluids.
This study investigates the opto-structural properties of Poly(methyl methacrylate)-Polyaniline-Tin sulphide (PMMA–PANI–SnS) nanocomposite films synthesized via a chemical approach. The structural, morphological, and optical properties of the nanocomposites were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), Energy-dispersive X-ray (EDX), UV–Vis spectroscopy, and Fourier-transform infrared (FTIR) spectroscopy to evaluate potential optoelectrical device applications. The results reveal that the incorporation of PANI and SnS into PMMA enhances the optical absorption of the nanocomposite with a uniform dispersion of nanoparticles observed in the polymer matrix. These findings suggest that PMMA–PANI–SnS nanocomposites potential for further investigation in optoelectronic devices, subject to additional electrical characterization. FTIR analysis reflects the formation of hydrogen bonds between PANI and PMMA, while XRD data show an increase in amorphous domains in the nanocomposites compared to the pure polymer blend. UV–Vis spectroscopy indicates a decrease in the optical energy gap with increasing SnS content in the nanocomposites.
In fused filament fabrication/fused deposition modeling (FFF/FDM), the mechanical properties of Polyamide 6 (PA6) are strongly governed by thermal conditions during printing, particularly the build chamber temperature, which controls cooling rate, crystallinity, and interlayer bonding. This study evaluated three build chamber temperatures (30, 40, and 50°C) while keeping all other parameters constant to determine their effects on tensile strength, impact toughness, and microstructure. Five specimens per condition were tested for tensile and impact properties, and fracture surfaces were characterized by scanning electron microscopy (SEM). The results demonstrate a clear temperature dependence: increasing the chamber temperature from 30 to 50°C enhanced tensile strength from 21.32 to 24.61 MPa and impact toughness from 13.58 to 14.35 kJ/m2, whereas 40°C yielded the lowest values of 16.09 MPa and 11.37 kJ/m2. SEM observations suggested that specimens printed at 50°C exhibited improved filament fusion and fewer interlaminar voids, resulting in a more homogeneous and ductile fracture surface, whereas specimens printed at 40°C showed less uniform interlayer bonding and a more heterogeneous defect distribution. These observations are consistent with enhanced interlayer bonding under more favorable thermal conditions. The findings indicate that approximately 50°C is the optimal build chamber temperature within the investigated range, providing improved mechanical reliability of FFF/FDM-printed PA6 parts and a basis for optimizing the processing window for load-bearing applications.
This study reports the structural, morphological, mechanical and dielectric behavior of solution-cast poly(methyl methacrylate) (PMMA) films containing trace fractions (0.5 and 1
