Effect of aluminum oxide nanoparticles additives and gamma irradiation on the structural and optical properties of syndiotactic polystyrene

2019

Polymer Composites

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Syndiotactic polystyrene (sPS) containing 3, 5, 7, and 10 wt % of aluminum oxide (Al 2 O 3 ) nanoparticles were prepared following the melt-mixing technique. The thermal behavior of the sPS/Al 2 O 3 nanocomposites was investigated through differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and melt flow index (MFI). The DSC results indicated that for all sPS/Al 2 O 3 nanocomposites, the melting temperature (T m ), the melting enthalpy (ΔH m ), the crystallization temperature (T c ), and the glass transition temperature (T g ) increased with an increase in the Al 2 O 3 nanoparticles content. The TGA analysis indicated that the thermal stability of all nanocomposites is significantly enhanced after the addition of Al 2 O 3 nanoparticles with different contents. The activation energy was determined through two different models: the Coats-Redfern model and Broido's models were utilized to measure the activation energy of thermal decomposition by assuming first-order kinetics. The results of both methods have displayed a high level of agreement. Our study extended to study the MFI of the sPS/Al 2 O 3 nanocomposites. The MFI reduced when the Al 2 O 3 nanoparticles content increased. The effect of gamma irradiation on the thermal behavior of the sPS/Al 2 O 3 nanoparticles was also investigated at different gammaabsorbed doses. Significant modifications were observed in the thermal behavior of sPS/Al 2 O 3 nanocomposites after the irradiation process, and the experimental data indicated that the addition of Al 2 O 3 nanocomposites in small loading contents and gamma irradiation can significantly help improve the thermal properties of sPS. POLYM. COMPOS., 40:3588-3600, 2019.FIG. 3. (a) The changes in melting temperature (tm) and (b) the changes in melting enthalpy (Hm) as a function of Al 2 O 3 nanoparticles content for the pure sPS and sPS/Al 2 O 3 nanocomposites before and after gamma irradiation. FIG. 7. Some plots of the Coats-Redfern method of thermal decomposition for (a) pure sPS, (b) sPS/3%Al 2 O 3 nanocomposite, and (c) sPS/5% Al 2 O 3 nanocomposite.

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Investigation of the effect of aluminum oxide nanoparticle additives and gamma irradiation on the thermal behavior of syndiotactic polystyrene

Abdeldaym

2019

Polymer Composites

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“…Notably, these alterations are attributed to the crosslinking or chemical bond scissions caused by high energetic radiation. This is because the ionization and excitation of the material's molecules occurring during the interaction of ionization radiation with a polymeric material [30]. The radiation processing technique has numerous advantageous features including easy process control, simultaneous crosslinking of polymers and sterilization at the same time, and the technology is environmentally-friendly and no residue or pollutant in the surrounding environment, no additional chemical initiators or crosslinkers [31,32].…”

Section: Introductionmentioning

confidence: 99%

Development of Cotton Fabrics via EVA/SiO2/Al2O3 Nanocomposite Prepared by γ-Irradiation for Waterproof and Fire Retardant Applications

Elbarbary

J Inorg Organomet Polym

Gad

2022

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Development of cotton fabric (CF) properties using nanocomposites via coating method was of considerable interest for wide applications. This article aims at developing CF properties by coating treatment using ethylene–vinyl-acetate (EVA), silicon dioxide (SiO2), aluminum oxide (Al2O3) nanoparticles and γ-irradiation widely used in waterproof and flame retardant applications. EVA-based nanocomposites, EVA/SiO2, EVA/Al2O3, and EVA/SiO2/Al2O3, were synthesized by γ-irradiation and the highest gel content of 81.2–95.3% was achieved at 30 kGy. The physicochemical properties of EVA-based nanocomposites were characterized by FT-IR, XRD, DSC and SEM techniques. Usage of irradiated EVA and EVA-based nanocomposites for treatment of CF by coating technique was successfully achieved. This technique provides a simple and versatile method leading to excellent uniform and smooth surface morphology without aggregation. The weight gain, mechanical properties, thermal properties, water vapor permeability and flame-retardant properties of the modified CF were evaluated. Moreover, compared with control CF, the resistivity of water absorptivity and hydrophobic property and the thermal stability were gained. The flame retardant properties of CF samples were performed using limited oxygen index (LOI) and vertical burning flame tests. LOI percentages of CF/EVA/SiO2, CF/EVA/Al2O3 and CF/EVA/SiO2/Al2O3 increased to 25.3, 27.5, and 29.3%, respectively. Untreated CF ignited and burned rapidly after 5 s. Meanwhile, the treated CF hold flame resistance properties and the burning time prolonged to 25 s. The results of the treated CF providing revealed hydrophobic and protective capability of the fabrics from being destroyed by burning, and support their further use in waterproof and flame retardant applications of fabrics.

“…25 This is because the ionization and excitation of the material’s molecules occurs during the interaction of ionization radiation with a polymeric material. 26 It is for this reason that polymer investigation has emerged into a prominent area of research, primarily in industrial applications including electronic devices, wires and cables. The current study aims to investigate the impact of adding varying contents of CuO nanoparticles and gamma radiation at different doses, on the microstructures, mechanical and DC-Electrical properties of nylon 66 and comparing the findings with the results of irradiated samples.…”

Section: Introductionmentioning

confidence: 99%

Role of copper oxide nanoparticles and gamma irradiation in optimising mechanical and the DC-electrical properties of nylon 66

Abdeldaym

Journal of Composite Materials

2020

This study used an aqueous precipitation method to synthesise copper oxide (CuO) nanoparticles. Nylon 66/CuO-based nanocomposites were prepared through a melt-mixing process using CuO nanoparticles with differing contents (1, 2, 3 and 4 wt%) and varying doses of gamma radiation (100, 200 and 300 kGy). The study also investigated the impact of these combinations on the structural, mechanical and DC-electrical attributes of nylon 66. The combination of CuO nanoparticles and gamma irradiation caused nylon 66 to undergo structural changes verified through X-ray diffraction measurement and Fourier-transform infrared spectroscopy. Scanning electron microscopy was used to examine the morphology of the nylon 66/CuO nanocomposites and revealed that the CuO nanoparticles belonging to the nylon 66 matrixes had a homogeneous dispersion. According to the mechanical finding, the influence of CuO nanoparticles and gamma irradiation significantly augmented the flexural strength and flexural modulus of the nanocomposites. However, this addition led to a decline of elongation at break. To better understand the tensile mechanism, a correlation of tensile strength using theoretical models premised on Money, Einstein and Pukanszky were undertaken. The optimal deviation was exhibited by the Pukanszky model using tensile plots on an experimental basis. The study also examined the nanocomposite’s DC-electrical conductivity; electrical conductivity increased with CuO nanoparticle content and gamma irradiation. For every sample, the prevailing transport mechanism was the Poole–Frenkel emission. This finding is encouraging for the development of innovative materials with augmented tensile strength and nanoelectronic devices.