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With a growing population of about 7.8 billion, humans are generating tons of waste in the form of non-biodegradable plastics on a daily basis that ends up in landfills and oceans. The introduction of packaging has been a blessing to mankind by facilitating the ease of convenience in transportation, delivery and general usage. The downside, however, is that majority of the packaging currently available is harmful to the environment and takes thousands of years to decay. This paper discusses the use of chitosan from shrimp shells and other marine animals' exoskeleton waste in food packaging industries. Chitosan extracted from marine organisms is modulated in the form of packaging material. Compared to conventional packaging, chitosan films are 73.4% biodegradable in soil under laboratory conditions whereas 100% degraded in an open field. Chitosan with metal oxides, essential oils, natural extracts, proteins and other polymers show enhanced tensile strength, water vapor permeability, oxygen and ultraviolet barrier. Chitosan and composite film show antimicrobial activity against gram positive and negative bacteria. Comparative approaches on environmental impacts between conventional plastics and chitosan films are enlightened, thereby highlighting the importance of natural polymers as packaging films that are considered economic based on the addition of additives. [ABSTRACT FROM AUTHOR]

This study assessed bioplastics made from different mass proportions of commercial chitosan and banana plant pseudostem-derived hemicelluloses. The bioplastics were prepared by the casting method and characterized for moisture content, water solubility, opacity, water absorption, tensile strength, and thermogravimetric properties. The formulations with hemicelluloses addition showed higher moisture content and water solubility than the chitosan-only bioplastic, the maximum values of these properties (22.3 and 22.4%) were achieved when hemicelluloses were added at the proportion of 10 and 5%, respectively. A positive linear correlation (r = 0.86) was found between added hemicelluloses and opacity, with the highest opacity (1.95 mm−1) achieved in the formulation with the maximum hemicellulose incorporation. The bioplastics containing hemicelluloses exhibited lower swelling (water absorption) than that made only of chitosan, with the formulation featuring the highest hemicelluloses content showed the lowest swelling (229.2%). A negative linear correlation (r = 0.95) was observed between added hemicelluloses and swelling values. The formulation with the highest hemicelluloses content demonstrated statistically significant differences and exhibited the highest tensile strength (18.7 MPa) and Young's modulus (66.1 MPa). Thermogravimetric analysis revealed four stages of mass loss in the bioplastics. Hemicelluloses addition decreased the temperature at maximum mass loss, and the formulation with the lowest hemicelluloses content showed a higher degradation rate than the others. [ABSTRACT FROM AUTHOR]

Plastic waste can serve as a symbolic expression of environmental pollution because of its prevalence and extremely slow degradation. A well-known example of synthetic plastics is low-density polyethylene (LDPE). A pragmatic approach to mitigate the environmental problems is to develop biodegradable plastic without compromising the quality of properties or increasing the price. To meet these requirements, one must turn to polymers from natural sources, such as starch. Starch is a fully biodegradable, semi-crystalline, non-toxic polymer with difficulties in processing. To obtain thermoplastic starch (TPS), a biodegradable glycerol plasticizer and sheer processing are necessary over a so-called gelatinization. Here, we aim to prepare and investigate sustainable and environmentally friendly packaging materials based on biodegradable blends, such as LDPE_TPS. The prepared blends were subjected to extensive physicochemical characterization to clarify the functional performance and biodegradability. Changes in structure, morphology and chemical composition before and after biodegradation were interpreted and correlated. Problems such as high interfacial tension due to high incompatibility between the non-polar polyolefin and the highly polar TPS were alleviated for some blends. The observation of mechanical, diffusive and composting parameters suggests that the modifier plays a crucial role in obtaining homogeneous polymer blends. The study of LDPE_TPS blends shows that it is possible to produce polymer blends with good biodegradability and balanced mechanical performance at a reasonable price. [ABSTRACT FROM AUTHOR]

Biodegradable plastics are among the most promising materials to replace conventional petroleum-based plastics that have caused many adverse impacts on the environment, such as pollution (land, water, etc.) and global warming. Among a range of biodegradable plastics, poly lactic acid (PLA) is not only widely available but also safe to be decomposed after its usage without polluting the environment. PLA is also in parity with other conventional plastics such as PP, PET in terms of various properties suitable for industrial usage such as mechanical, physical, biocompatibility and processability. Thus, PLA has become the most used biopolymers in many industries such as agriculture, automotive and packaging by having these characteristics. Its higher demand has contributed to a stable increment in the global PLA market. In fact, over the years, the market for PLA has grown up and will keep on expanding in the future. Overall, the PLA-based bioplastic would be an excellent substitute for the existing conventional plastics in various applications, hence will serve to protect the environment not only from pollution but also work as a sustainable and economical product. This paper will review all the recent related works and literature on PLA as the biodegradable material regarding its properties, usability, productivity and substitute. [ABSTRACT FROM AUTHOR]

Waterborne polyurethane (WPU) prepolymer with acrylate terminal was prepared by using hydroxyethyl acrylate as an end-capping agent. Modified gelatin (mGH) was prepared by grafting vinyl groups which were obtained from hydrolysis and condensation of vinyl trimethoxysilane onto the renewable natural polymer material cold-water fish skin gelatin. Due to the excellent biodegradability and mechanical properties of cold-water fish skin gelatin, mGH was introduced into the WPU backbone by covalent bonding to improve WPU comprehensive property. The vinyl groups in mGH and the acrylate ends in the WPU prepolymer were connected by UV curing to prepare biodegradable and renewable mGH/WPU chemical hybrid materials. The test results showed that the film-forming properties, the water resistance and thermal stability of WPU were improved by covalent bonding. Water contact angle increased from79.6° to 96.5°, and the maximum thermal degradation rate temperature increased from 340 to 400 °C. In addition, incorporation of mGH with high modulus improved the moduli and yield strength of WPU, in which the yield strength increased from 11.3 to 18.2 MPa. The degradation performance of mGH/WPU chemical hybrid materials was also evaluated that the degradation rate reached 68% in 0.6% lipase PBS solution and 56% in soil after 60 days. The study provides a novel polymerization method for preparing high biodegradable decorative coatings and prints of specialty metals, polymer plastics and certain types of woodware as well as medical scaffold materials. [ABSTRACT FROM AUTHOR]

Two methods, nanoprecipitation and emulsification/solvent evaporation with different solvents, to prepare nano and microparticles of polylactic acid (PLA) and PHBV are investigated. The obtained particles are characterized in terms of morphology by SEM and thermal properties by DSC and TGA. The objective is the preparation of PLA and PHBV nano and microparticles, with controlled shape and size distribution, for their further inclusion into biopolymer matrices such as PLA, PHBV or thermoplastic starch matrices. The purpose is the use of these biocomposites in the sector of wrapping and packaging. Good thermal properties of the nano and microparticles are important to the posterior processing as extrusion film technique. Although the smallest particles are obtained for PLA using nanoprecipitation technique with THF as solvent, these nanoparticles show a low thermal stability. The emulsification technique using dichloromethane as solvent shows to be a good option to obtain, for PLA and PHBV, spherical particles with controlled size and adequate thermal stability. The reproducibility of the selected method is studied for up-scaling nano and microparticle production to pre-industrial level. This study of reproducibility using statistical analysis shows the robustness of the methodology. [ABSTRACT FROM AUTHOR]