Introduction: Plastic in any form is harmful to the environment. Its non-degradable nature leads to plastic pollution. Various chemical and biological methods have been attempted to address this issue, but chemical approaches have often resulted in pollution due to the release of toxic gases. Biodegradation is one of the methods that has received much attention in recent years. This study focused on the biodegradation of plastic waste bags using five marine-derived fungal strains isolated from Red Sea.Materials and Methods: The sediment samples were collected from the Red Sea. Samples were subjected to fungal isolation using the serial dilution and spread plate technique. Fungal species isolates were evaluated for degradation activity toward Low-density polyethylene ((LDPE)) strip samples. The degraded plastic strips were analyzed for weight loss, AFM, SEM, and GC-MS to identify degradation byproducts.Results: The results showed that only two fungal strains (Aspergillus terreus (OQ271754) and Alternaria alternata (OQ282860)) exhibited significant degradation activity over 8 weeks, leading to a weight loss of 45.83% and 29.16% in the degraded plastic strips, respectively. AFM and SEM images of the degraded strips by these strains revealed a noticeable change in surface roughness and close attachment of spores compared to control strips. GC-MS analysis of degradation byproducts identified several compounds, with Bis(2-ethylhexyl) phthalate being the major compound. Toxicity testing of this compound on Wheat seeds showed a significant impact on seed germination.Conclusions: This study demonstrates the potential of marine-derived fungi to degrade plastic materials through the action of their secondary metabolites, resulting in significant weight loss and changes in surface texture.

The loss of energy, especially in industrial and residential buildings is one of the main reasons of increased energy consumption. Improving the thermal insulation properties of materials is a fundamental method for reducing the energy losses. Polymeric foams are introduced as materials with excellent thermal insulation properties for this purpose. In the present study, a deep theoretical investigation is performed on the overall thermal conductivity of Low-density polyethylene ((LDPE)) foams. The thermal conductivity by radiation is predicted using two different methods. The most appropriate model is selected through comparing results with experimental data. The results show that the theoretical model has an appropriate agreement with the experimental results. The effects of foam characteristics including foam density, cell size, and cell wall thickness on the overall thermal conductivity are investigated. The results indicate that by decreasing the cell size and increasing the cell wall thickness, the overall thermal conductivity is decreased significantly. Also, there is an optimum foam density in order to achieve the smallest thermal conductivity. The Lowest overall thermal conductivity achieved in the studied range is 30 mW/ mK at a foam density of 37. 5 kg. m-3, cell size of 100 μ m, and cell wall thickness of 6 μ m.

In this study, a biodegradable composite for food packaging application was produced. Low density polyethylene as matrix, lingo-cellulosic powder of wheat straw as filler, and MAPE (Maleic Anhydride polyethylene) and PEG (polyethylene Glycol 400 and 600) as compatibilizers were used to preparation of these biocomposites. Mechanical characteristics (tensile, three points flexural and impact tests) of samples were performed to produce the best compound regarding the compatibilizers effect. Different weights of filler phase in levels: 70 to 30, 60 to 40, 50 to 50, and 40 to 60 % were used in the composite formulation. Compatibilizers were also applied in three levels of 0, 7, and 10 %. The results showed that the MAPE was the best compatibilizer as to improving the mechanical properties of the compounds. The type of compatibilizer is ineffective on the impact results. All composites were better than the control sample in the flexural tests.

High-density polyethylene (HDPE)/linear Low-density polyethylene (L(LDPE)) blends have been designed by varying the HDPE: L(LDPE) ratio. The ratio of 70: 30 showed the best combination of tensile properties (19. 53 MPa), melt fLow index (MFI) (1. 75 g/10 min) and hardness properties (Shore D 46. 5), and its tensile strength and hardness was greater than those of plain L(LDPE), whereas its MFI was greater than that of a plain HDPE. Hence, with the same composition, the composites were made by addition of silica with a ratio of 10–, 40%. Incorporation of silica acts as a reinforcement into the system and improves the structural rigidity and 30% incorporation showed the best performance in terms of tensile (23. 69 MPa), and hardness (Shore D 48) but slightly less MFI (0. 85 g/10 min) of the composites. Incorporating coconut shell charcoal (CSC) not only improves the system’, s performance but also utilizes its waste and properties are measured as tensile strength (22. 33 MPa), maintaining the hardness properties and slight reduction in MFI (0. 77 g/10 min). All blends and composites were processed through extrusion and palletization folLowed by compression molding. Plain silica, CSC as well as the selected blends and composites were evaluated by FTIR, XRD, and SEM analyses. Hence, the synergistic effect of silica and CSC in the HDPE-L(LDPE) blend is studied and such a composite can be suitable in automotive applications.

In recent years, application of nanotechnology in the food packaging industry has become more widespread and is progressively being commercialized. Adding nanomaterials improves polymers` barrier properties for gases such as O2 and Co2, and increases UV rays barrier, mechanical strength, stiffness, stability, and heat resistance of the base polymer. In this study, Low density polyethylene film ((LDPE)) with 5 wt % nanoparticles of clay was used as the experimental treatment and Low density polyethylene film as control treatment. These films were used for packaging of rainbow trout fillets and keeping them in the refrigerator. Then to investigate the quality of packed fillets, samples were taken in days 0, 5, 10, 15, 20 and 25, and were evaluated using chemical (pH, PV, TBA, TVB-N), microbial (TVC, PTC, LAB, EBC and H2S producing bacteria) and sensory tests. Based on the results, significant differences (p<0. 05) were observed between control and experimental treatments in different days. The sensory attributes of rainbow trout fillets correlated well with the microbiological analyses (r=0. 91). With regards to sensory scores and the microbiological analysis, the shelf-life of rainbow trout fillets has been determined in the control and experimental treatments, 13 to 15 and 18 to 20 days, respectively.

Application of Nanotechnology in the food packaging industry in recent years become more widespread and is being commercialized. Add nanomaterials, caused an improvement barrier properties of polymers to gases such as oxygen and carbon dioxide, increased UV rays barrier, mechanical strength, stiffness, stability and heat resistance of the base polymer. in this study composite film with 5% nanoparticles of clay were produced as experimental treatment and Low density polyethylene((LDPE)) film as a control treatment and was used for packing rainbow trout fillet and kept in the refrigerator. Then to investigate the quality fillets packed on days zero, 5, 10, 15, 20 and 25 was used chemical tests (pH, TVB-N, PV, TBARS), microbial (TVC, PTC, LAB, EBC and H2S producing bacteria) and sensory. Based on the results obtain of the tests and data analysis have been observed significant differences between treatments on different days and thus, shelf-life of rainbow trout fillet have been determined in the control and experimental treatments respectively, 13 to 15 and 18 to 20 days.