Pretreated Polyethylene Research Articles

Biodegradation of pretreated polyethylene film by Pseudomonas aeruginosa AMB‐CD‐1

AbstractA comparative study evaluated the acid, alkali, and heat‐treated polyethylene biodegradation efficiency of Pseudomonas aeruginosa AMB‐CD‐1. The polyethylene (PE) pieces were separately treated with heat (50°C), acid (1N HCl), and alkali (1N NaOH) and then washed with water before use. All the treated samples were analyzed through thermogravimetric analysis. In addition, weight and temperature changes during the decomposition reactions were also measured and determined. In these treatments, the PE films of heat‐treated and acid‐treated low‐density polyethylene (LDPE) indicated more significant weight loss at 120°C (48.99% and 40.75%, respectively) as compared to their control or untreated PE and alkali‐treated LDPE (21.84% and 24.68%, respectively). A biodegradation assay was then conducted with treated and untreated LDPE films with P. aeruginosa AMB‐CD‐1 strain. Fourier transform infrared spectroscopy analysis revealed that the heat or acid‐pretreated samples with isolate AMB‐CD‐1 displayed peaks at 2922.84, 2923.97, and 1450.31, 874.22 cm−1 for C–H stretching deformation vibration, CH2 scissoring vibration, –CHO stretching, and strong alkyl structure, respectively. Furthermore, the new peaks with a significant difference at 2500–2000 cm−1 (O═C═O, O–H stretching vibration: carboxylic acid) and 1500–1000 cm−1 (–CHO and C═O stretching) were noticed in the infrared spectral range of LDPE degradation. Modifications in the functional group provided evidence that biodegradation had impacted the chemical structure of the LDPE film. Additionally, it was demonstrated that pretreating LDPE films with heat or acid could speed up their biodegradation.

Effect of Treatment in a Weak Electromagnetic Field on the Infrared Spectrum of a Polyethylene Film

Changes in the IR spectrum of a pretreated polyethylene film during resonant irradiation by a weak electromagnetic field were measured for the first time.

Biodegradation of Polyethylene Using Bacillus Subtilis

Polyethylene is among the major plastics being dumped in the environment. The study explores methods to enhance the rate of biodegradation of polyethylene using physical and biological means. Bacterial species –Bacillus subtilis – was tested for its potential in utilizing polyethylene as their sole carbon source. The microbial species produced surface active compounds (Biosurfactants) that enhance the degradation process. Pretreatment of polymer films with Ultraviolet radiation aids its accessibility as food for the microorganisms thus enabling a much faster rate of biodegradation. Inoculation of pretreated polyethylene films of thickness 18μ with Bacillus subtilis with the addition of its biosurfactant (surfactin) proved to be most efficient with a weight loss percentage of 9.26% in 30 days

Roll-to-roll DBD plasma pretreated polyethylene web for enhancement of Al coating adhesion and barrier property

In this paper the roll-to-roll atmospheric dielectric barrier discharge (DBD) was used to pre-treat polyethylene (PE) web surface before the conventional thermal evaporation aluminum (Al) was performed as a barrier layer. We emphasized the plasma environment effect based on the inlet three kinds of reactive monomers. The cross hatch test was employed to assess the Al coating adhesion; and the oxygen transmission rate (OTR) was used to evaluate gas barrier property. The results showed that after roll-to-roll DBD plasma treatment all Al coatings adhered strongly on PE films and were free from pinhole defects with mirror morphology. The OTR was reduced from 2673cm3/m2day for Al-coated original PE to 138cm3/m2day for Al-coated allyamine (C3H7N) modified PE. To well understand the mechanism the chemical compositions of the untreated and DBD plasma pretreated PE films were analyzed by X-ray photoelectron spectroscopy (XPS). The surface topography was characterized by atomic force microscopy (AFM). For the property of surface energy the water contact angle measurement was also carried out in the DBD plasma treated samples with deionized water.

Innovative transparent non-scattering TiO2 bactericide thin films inducing increased E. coli cell wall fluidity

This study presents the first account for transparent, non-scattering TiO2 films on radio-frequency (RF) plasma and ultraviolet light in the C-spectral region (UVC) pretreated polyethylene (PE). These pretreatments allow the PE to bind higher amounts of TiO2 necessary to induce E. coli inactivation in the minute range under simulated sunlight irradiation. The uniform TiO2 film was sputtered by direct current magnetron sputtering (DC). These higher TiO2 loadings were necessary to obtain faster bacterial inactivation kinetics on the PE films. The peak shifts in the stretching of the symmetric and asymmetric vibrational infrared spectra of the CH groups were followed during the time of bacterial inactivation (60min). This time was concomitant with the time required for the hydrophobic to hydrophilic transition on PE-TiO2. The production of malondialdehyde (MDA) was observed during E. coli loss of viability. PE pretreatment led to a significant increase in the TiO2 loadings on the PE surface as shown by X-ray fluorescence (XRF), X-ray-diffraction (XRD) by X-ray photoelectron spectroscopy (XPS).

Controlled release of encapsulated methylene blue in a multilayered textile coating

We studied the formation of multilayered coating incorporating a β-cyclodextrin polyelectrolyte onto a pretreated polyethylene terephthalate (PET) textile in order to obtain reservoir and sustained release properties towards bioactive molecules. This paper describes the alternate deposition by dip-coating onto the textile of chitosan (CHT) and a β-cyclodextrin polyelectrolyte (polyCTR- βCD) according to the layer-by-layer (LbL) principle. Textiles covered with up to 12 layers were characterized by gravimetry, infrared, zetametry. The building of the multilayer system was then achieved including methylene blue (MB) as bioactive model compound, complexed with polyCTR-βCD, and a release study of BM was investigated in batch. The results showed that the release profile of BM could be controlled by the number of layers in the system.

Adhesion of PE modified by capacitively coupled radio frequency plasma-induced graft polymerization of glycidyl methacrylate

A graft polymerization of glycidyl methacrylate (GMA) on the pretreated polyethylene (PE) sheet samples by oxygen capacitively coupled radio frequency (RF) plasma was carried out to improve the adhesive properties of PE. The PE samples were treated with a RF power of 200 W for a treatment time of 40 s and then exposed to an oxygen atmosphere for a saturation time of 10 min. The grafting of the plasma pretreated PE performed in an aqueous GMA solution with the monomer concentration from 20 vol.% to 100 vol.% at a temperature from 20°C to 90°C for a reaction period up to 50 h. The optimum wettability of the graft polymerized PE surface with the concentration of 40 vol.% at the temperature of 70°C and for the time of 24 h was obtained as the static contact angle decreased from 104.2° for the original PE to 67.6° for the graft polymerized. After the graft polymerization, a strong absorption peak of C-O bonding was shown at 1050 cm−1 in Fourier transform infrared spectrum, indicating an introduction of epoxy groups on the graft polymerized surface. Correspondingly, the surface roughness (Ra) increased from 0.137 μm for the original PE to 1.660 μm for the graft polymerized. The maximal lap adhesive strength of the graft polymerized PE samples lapped using a mixture of epoxy resin and curing agent was achieved to about 160 N·cm−2. The fractured surfaces by tearing of the PE sheet matrix were observed on the tensioned PE samples due to the higher adhesive strength than that of the PE matrix.

The effect of maleic anhydride grafting on the flame retardation of plasma pretreated polyethylene

A rotating cylindrical-type argon plasma treatment system was used for pretreating low-density polyethylene (LDPE) to graft polar vinyl monomers. Maleic anhydride (MA) was used to graft onto plasma-treated LDPE (PLDPE) using UV-induced polymerization. The MA-grafted PLDPE (MA-g-PLDPE) was characterized by FT-IR spectra, SEM, TGA and ESCA measurement. The modified PLDPE was blended with a commercial flame-retardant additive (FR 44-94S), a coupling agent, lubricant and antioxidant to improve the flammability. The flammability of these blends increases with increasing amounts of FR 44-94S. However, the tensile strength and impact strength were decreased as the amount of FR 44-94S increased. From the results of notched Izod impact strength vs flame-retardant content, this flame-retardant seemingly exhibited plasticizer characteristics. As MA-g-PLDPE and FR 44-94S were blends, the mechanical strength, such as the tensile strength, impact strength, Young's modulus and LOI increased because the grafted MA can enhance the affinity between matrix and additives.