Radiation-induced graft copolymerization of acrylic acid/acrylonitrile onto LDPE and PET films and its biodegradability

Sorption of 60Co(II) from aqueous solutions onto biosynthesized zinc oxide nanocomposites

Nano ZnO is biosynthesized using Lactobcillus sp. Poly Acrylic acid-co-Acrylonitrile/ZnO, PAACAN/ZnO, and poly Acrylic acid-co-Maleic acid/ZnO, PAACMA/ZnO, nancomposites were synthesized using 60Co γ-rays. PAACAN/ZnO and PAACMA/ZnO nanocomposites were characterized and used as sorbents for 60Co(II) radionuclide. The monolayer adsorption capacities of 60Co(II) onto PAACMA/ZnO and PAACAN/ZnO are 18.235, 7.105 mgg−1, respectively at pH 4.5 and 20 °C. The sorption reaction has a pseudo 2nd order mechanism. 0.1 M EDTA could be used as an eluent for desorption. The desorption efficiencies of 60Co(II) from PAACAN/ZnO and PAACMA/ZnO were 67.51 and 84.85%, respectively. The sorption process is endothermic and spontaneous.

Effect of pro-oxidant concentration on characteristics of packaging films of cobalt stearate filled polypropylene

In this work, polypropylene (PP) filled with different proportions of CoSt were prepared in a twin-screw extruder by compounding technique. Eight films of these compounds were prepared using compression moulding. The modified PP films were characterized for chemical, physical, thermal, and morphological properties (before and after biodegradation). The biodegradation of the CoSt filled PP films was studied under controlled composting conditions, and the degradation intermediates were evaluated for their ecotoxicological impact. The CoSt present in the PP film was confirmed by Fourier transform infrared spectroscopy. As the addition of CoSt was progressively increased, the tensile strength and thermal stability decreased as shown by UTM and thermogravimetric analysis. The compounding of CoSt in PP reduced its crystallinity as revealed by the differential scanning calorimetry and X-ray diffraction analysis, and this led to enhanced degradation of PP. After biodegradation, SEM results of modified PP films showed rougher morphology than before biodegradation. The maximum biodegradation (19.78%) was shown by the film having 2 phr CoSt. The ecotoxicity tests of the degraded material, namely, microbial test, plant growth test, and earthworm acute-toxicity test demonstrated that the biodegradation intermediates were nontoxic. Hence, CoSt filled PP has high industrial potential to make biodegradable flexible packaging.

Morphology, rheology and biodegradation of oxo-degradable polypropylene/polylactide blends

The blends of polypropylene (PP)/polylactide (PLA) with or without compatibilizer, and with pro-oxidant (cobalt stearate/calcium stearate) and pro-oxidant filled PP were prepared by using the melt blending technique. Films of these blends were prepared by compression molding. PP85PL15 and PP85PL15MA4 were the optimum blends from the tensile strength point of view. The improvement in the tensile strength of PP85PL15MA4 blend was achieved by addition of 4 phr compatibilizer. Cobalt stearate and calcium stearate were added separately to PP85PL15MA4 blend in 0.2% (w/w) ratio. The optimized blends were further characterized by differential scanning calorimetry, X-ray diffraction, rheological studies, scanning electron microscopy (SEM) and biodegradability test. Rheological studies confirmed the pseudo-plastic nature of all the blend samples. SEM studies have revealed that the addition of PLA in PP85PL15 enhances the void and roughness on the blend. All the prepared blends have biodegraded in the composting environment and the blend containing pro-oxidant biodegraded to the maximum extent.

Surface Modification of PET Fabric by Graft Copolymerization with Acrylic Acid and Its Antibacterial Properties

Graft copolymerization of acrylic acid (AA) onto Poly(ethylene terephthalate) (PET) fabrics with the aid of benzoyl peroxide was carried out. The effect of polymerization parameters on the graft yield was studied. Percent grafting was enhanced significantly by increasing benzoyl peroxide (BP) concentrations up to 3.84 g/lit and then decreased upon further increase in initiator concentration. Preswelling of PET leads to changes in its sorption-diffusion properties and favors an increase in the degree of grafting. The antibiotics treated grafted fabrics showed antibacterial properties towards gram-positive and gram-negative microorganisms. FTIR and SEM were used to characterize AA-grafted polyester fabrics.