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Blend films of polyvinyl alcohol (PVA) with starch (St) were obtained by casting method. The effect of different contents of glycerol (Glyc) and citric acid (CA) was investigated. The successful preparations of different compositions were shown by FTIR analysis. The bioblend film of PVA/St/CA/Glyc with a composition of (2:1:1/10 vol %) was selected due to its water resistance, higher mechanical properties, and good thermal stability than other prepared bioblend films. Further improvements were obtained by irradiation with gamma rays at a dose of 10 kGy, where the water resistance was highly reduced and the tensile strength strongly improved. The thermal stability increased with the increasing of irradiation doses up to 30 kGy. The modified thermal and mechanical properties of the selected film either non-irradiated or irradiated were compared with widely used commercially packaging films such as LDPE and PP films. Compared to commercially packaging films, the selected PVA/St bioblend film has higher tensile properties, good and closely thermal properties either non-irradiated or irradiated one. Hence, the study showed the development of modified PVA/St bioblend film, which can be used in many fields such as the packaging industry. [ABSTRACT FROM AUTHOR]

Synthesis of antimicrobial films for packaging applications is eminent fields of research. This study describes preparation of biodegradable Poly (PVA/PLA/TiO2) nanocomposite films was carried out by blending polyvinyl alcohol (PVA) and polylactic acid (PLA) doped with titanium dioxide (TiO2) nanoparticles using solution casting method and then irradiated by γ‐irradiation. The properties of the films were characterized by FT‐IR, XRD, FE‐SEM, TEM, TGA, and mechanical tests. The addition of TiO2 nanoparticles (0.8 wt%) explored considerable effects on thermal stability of the films. Results of FE‐SEM and TEM illustrated quite uniformly dispersion of TiO2 nanoparticles with average size of 17.5 nm. The effect of γ‐irradiation on nanocomposite films showed enhanced water resistance property and water vapor transmission rate. The water resistance property was achieved using PVA/PLA composition ratio (2/1). The antibacterial activity was evaluated against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) bacteria. Poly(PVA/PLA/TiO2) nanocomposite film irradiated at 20 kGy displayed improved antibacterial activity and was selected for soil burial biodegradation tests. The biodegradation rate increased rapidly in the initial 12 weeks with significant changed morphology. The enhanced antibacterial efficiency and biodegradation property of the nanocomposite films suggest their possible use for development of packaging materials with low environmental impact. [ABSTRACT FROM AUTHOR]

Modification of low density polyethylene (LDPE) films by blending with Polylactic acid (PLA) and Starch (St) were carried out. Also, the study describes the comparison of two curing methods one by thermal curing at 70°C and the other is radiation curing at dose 20 kGy for the bioblend film composed of LDPE/PLA/St with composition (98%:1%:1% wt%). The efficiency of modification was determined by using different devices such as Fourier transform infrared (FTIR), mechanical, TGA, and XRD. In addition, the properties of the different bioblends were compared with other synthetic polymers such as commercial LDPE and blank LDPE. The results show that the improved properties of radiation cured method at dose 20 kGy than thermal treatment method at 70°C. The radiation cured bioblend film show good thermal stability either shown by the TGA results or against heating aging from ambient temperature up to 60°C than thermally treated blend film at 70°C. The radiation cured bioblend film found to be stable against UV‐ exposure with increasing time of exposure up to 30 min at higher wavelength (λ = 320 nm), which simulate ultraviolet radiation from sunshine. The modified properties of prepared radiation cured bioblend film are due to increase in interfacial adhesion bond between LDPE, PLA, and Starch by effect of irradiation dose at 20 kGy. The modified radiation cured bioblend films at 20 kGy can be applied in different fields such as packaging due to improvement in chemical, thermal, and mechanical properties that could partially replace the traditional petrochemical plastics. [ABSTRACT FROM AUTHOR]

Radiation-induced enteropathy is a major clinical challenge during radiotherapy. Resveratrol displays beneficial pharmacological activities; however, low oral bioavailability limits its effectiveness. This study aims at preparing methacrylic acid (MAAc) functionalized multi-walled carbon nanotubes (MWCNTs-MAAc) as carriers for pH triggered controlled release of resveratrol in an effort to improve the drug therapeutic potential. MWCNTs-MAAc were prepared using radiation technique and then characterized by transmission electron microscopy (TEM), dynamic light scattering (DLS), scanning electron microscope (SEM), X-ray diffraction (XRD) and Fourier transform-infrared (FT-IR) spectroscopy. In vitro drug release profile at different pH values was analyzed. Furthermore, the designed RES-MWCNTs-MAAc nanocomplex was evaluated against radiation-induced enteropathy in rats. Oral administration of RES-MWCNTs-MAAc restored colonic redox state and elevated antioxidant enzymes activities glutathione peroxidase (GPx), superoxide dismutase (SOD) and catalase (CAT) and reduced colonic inflammatory mediators tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β) and interferone-γ (IFN-γ) contents in addition to declining the intrinsic apoptotic pathway as evidenced by down-regulation of Bax and caspase-3 proteins expression accompanied by up-regulation of Bcl-2 protein expression. RES-MWCNTs-MAAc was more efficient than free resveratrol due to the delivery system that allowed prolonged resveratrol release at target site. Thus, this formulation could serve as a beneficial anti-inflammatory approach for patients during radiotherapy. [Display omitted] [ABSTRACT FROM AUTHOR]

Preparation of Low density polyethylene/polystyrene/maleic anhydride/nano Magnesium hydroxide LDPE/PS/MA/Mg(OH) 2 blend nanocomposite was carried out. The Mg(OH) 2 nanoparticles were investigated by XRD and TEM. The effects of different contents of polystyrene, maleic anhydride and nano magnesium hydroxide on the properties of the prepared blends and blend nanocomposite were investigated. From the mechanical properties the LDPE/PS/MA/Mg(OH) 2 blend nanocomposite with composition 70/30/10/5 wt % has higher tensile strength compared with pure LDPE. PS and other blend films. Since polymers used in the biomedical and packaging sectors exposed to ionizing radiation such as gamma rays for sterilization purposes, therefore the selected LDPE/PS/MA/Mg(OH) 2 blend nanocomposite films subjected to gamma irradiation at doses 0 up to 40 kGy. The FTIR, TGA analyses and the mechanical properties were used for monitoring changes in properties evaluated by radiation. The selected LDPE/PS/MA/Mg(OH) 2 blend nanocomposite films characterized by high chemical, thermal and stable structure against gamma irradiation up to 35 kGy than ordinary LDPE film. The limiting oxygen index (LOI) show that the selected irradiated blend nanocomposite has higher LOI value compared to original PS and nonirradiated blend nanocomposite films. The Field emission- SEM show the accumulation of the nano Mg(OH) 2 on the surface of selected LDPE/PS/MA/Mg(OH) 2 blend nanocomposite film then reduces to average particle size 153.5 nm by effect of gamma irradiation. The presence of Mg(OH) 2 nanoparticles did not alter the mechanical properties of the selected prepared LDPE/PS/MA/MgOH 2 blend nanocomposite film, also it increase thermal stability and enhance fire retardency which is better than traditional additives. Image 1 • The irradiated LDPE/PS/MA/Mg(OH) 2 (70/30/10/5 wt%) blend nanocomposite has improved properties than other blends. • The selected blend nanocomposite is chemically & thermally stable than original LDPE& PS. • Maleic anhydride improves the interfacial adhesion force between the low density polyethylene LDPE and polystyrene PS. • Mg(OH) 2 with particle size of 153.5 nm improves all properties than other traditional nano-filers. [ABSTRACT FROM AUTHOR]