Replacement Of Petroleum-based Polymers Research Articles

Optimization of ZnO/GO nanocomposite-loaded polylactic acid active films using response surface methodology

Development of biodegradable polymer as food packaging has been emerged with the increasing awareness of achieving sustainable development goals. As a replacement of petroleum-based polymers, Polylactic acid (PLA) has been widely utilized for food packaging. However, the main disadvantage of PLA for food packaging is its brittleness and low stiffness. Therefore, this work aimed to evaluate the potential usability of Zinc oxide (ZnO) and Graphene oxide (GO) as mechanical strengthening nanocomposites and their synergistic effect towards antibacterial property. The optimum formulation of PLA/ZnO/GO nanocomposite active film was determined using RSM by defining concentration of ZnO (0–1.5 wt%), concentration of GO (0–1.5 wt%) and mixing temperature (40, 50, 60 °C) as process parameters. The synergistic effect of ZnO/GO demonstrated a significant improvement in mechanical property. Both ZnO and GO exhibited significant antibacterial activity towards E. coli and B. subtilis and their synergistic antibacterial property performed the best with 0.75 wt% ZnO and 0.75 wt% GO at 50 °C. Results also revealed that ZnO was dominated in their synergistic effect for both mechanical and antibacterial properties. The optimum formulations for PLA/ZnO/GO nanocomposite active film were determined at 1.06 wt% ZnO, 1.11 wt% GO at 60 °C and 0.99 wt% ZnO, 1.28 wt% GO at 40 °C. The regression models by RSM were validated with the experimental results based on optimal formulations. In addition, SEM and FTIR investigation on two optimal films confirmed the good compatibility between ZnO, GO and PLA matrix. Taken together, optimized formula could provide useful insights for fabricating PLA-based active film and broadening their application in food packaging industry.

Preparation and characterization of bionanocomposite films based on wheat starch and reinforced with cellulose nanocrystals

In recent times, the attention of scientific community has been focusing on the replacement of petroleum-based polymers by others more environmentally friendly. In this sense, bionanocomposites based on glycerol-plasticized wheat starch and reinforced with cellulose nanocrystals (CNCs) were prepared by a solvent-casting process to obtain environmentally friendly films. The plasticization process was proven to be complete in the conditions used and no residual crystallinity was observed in any case. The incorporation of CNCs leads to materials with increased rigidity (about 1000% increment in modulus) which is related to a good filler-matrix interaction and to the formation of a rigid crystalline network of cellulose. This fact allowed also to improve the moisture resistance and the barrier properties (in both, oxygen and water vapor as permeant) of the bionanocomposite films due to the formation of a tortuous path, which prevent the gas diffusion. Moreover, the thermal stability of films was not affected by the filler incorporation. These improvements in the properties make these films susceptible to be used in short-time applications in the food packaging industry.

Engineering Styrenic Blends with Poly(lactic acid)

Polymer pollution from nonbiodegradable polymer blends is a source of increasing environmental concern. The obvious solution, the replacement of petroleum-based polymers with biodegradable polymers...

Thermoplastic Processing of PLA/Cellulose Nanomaterials Composites.

Over the past decades, research has escalated on the use of polylactic acid (PLA) as a replacement for petroleum-based polymers. This is due to its valuable properties, such as renewability, biodegradability, biocompatibility and good thermomechanical properties. Despite possessing good mechanical properties comparable to conventional petroleum-based polymers, PLA suffers from some shortcomings such as low thermal resistance, heat distortion temperature and rate of crystallization, thus different fillers have been used to overcome these limitations. In the framework of environmentally friendly processes and products, there has been growing interest on the use of cellulose nanomaterials viz. cellulose nanocrystals (CNC) and nanofibers (CNF) as natural fillers for PLA towards advanced applications other than short-term packaging and biomedical. Cellulosic nanomaterials are renewable in nature, biodegradable, eco-friendly and they possess high strength and stiffness. In the case of eco-friendly processes, various conventional processing techniques, such as melt extrusion, melt-spinning, and compression molding, have been used to produce PLA composites. This review addresses the critical factors in the manufacturing of PLA-cellulosic nanomaterials by using conventional techniques and recent advances needed to promote and improve the dispersion of the cellulosic nanomaterials. Different aspects, including morphology, mechanical behavior and thermal properties, as well as comparisons of CNC- and CNF-reinforced PLA, are also discussed.

Poly(Lactic Acid)/Poly(Vinyl Alcohol)/Graphene Nanocomposites

Poly(lactic acid) (PLA) is an interesting material as an environmentally-friendly replacement of petroleum-based polymers. However, some properties need improvements in order to commercially utilized PLA. In this work, graphene is used as a reinforcing filler and poly(vinyl alcohol) is used as a carrier to enhance dispersion of graphene in PLA matrix. The addition of graphene aims at improving the mechanical and thermal properties of PLA. The functional groups of graphene were characterized by Fourier transform infrared (FTIR) spectroscopy and X-ray diffraction (XRD). The mechanical property testing was performed using a universal testing machine. The thermal properties were measured through differential scanning calorimetry (DSC). As a result, the Young’s modulus and the thermal properties of PLA composites increased as the amount of graphene in the composites increased due to improved dispersion of graphene in PLA matrix.

Diffused Reflection of Micro-Cellular Foamed Polylactic Acid (PLA)

Microcellular foamed plastics have significantly contributed to the plastics industry by achieving weight reduction of the product and material cost savings. Limitations in petroleum resource reserves have lately propelled active research into foaming process. In particular, the extremely small cell size at less than 10μm and higher density for microcellular foaming process compared to the existing chemical foaming keeps its mechanical property decline small. In short, microcellular foamed plastics keep mechanical property decline to a minimum and deliver lightweight products. The research into microcellular foaming process thus far has focused on elevating foaming expansion ratio or keeping off mechanical property decline such as intensity. One of the most important trends in the polymer field nowadays is the replacement of petroleum-based polymers with bio-based ones. Among bio-based polymers, polylactic acid (PLA) and thermoplastic starch (TPS) are very attractive due to their availability, relatively low cost and their appealing physical and mechanical properties. This paper uses polylactic acid (PLA), which is a biodegradable material, to carry out foaming and describes research outcome of foamed PLA's optical properties. Desorption time was controlled during the test to change cell morphology and monitor the subsequent changes in diffused reflectivity. This research is the first-ever attempt to suggest new application areas of PLA, poor in mechanical properties.

Use of polymers from biomass in paints

Furan and its derivatives can be synthesised from renewable vegetable resources using simple chemical reactions. The use of copolymers of furan as a replacement of petroleum-based polymers in latex paints could be beneficial if the price of petroleum rises substantially. We have therefore substituted these with furan-based polymers and studied the paint properties. The copolymers of furan and furfuryl acetate with maleic anhydride were incorporated into commercial latex paint systems as a replacement for petroleum-based polymers. Although the paints formed were slightly more yellow than desired, they showed increased hardness and resistance to water.