Application Of Plastics Research Articles

Effect of plastics in applications of bituminous pavement: A laboratory study

In this study, an experimental investigation has been performed to modify bitumen using plastics. For each mixture sample, plastic content of 1%, 2%, 3%, 4% and 5% by the weight of bitumen are taken. Basic physical tests on conventional and Polymer Modified Bitumen (PMB) batches are carried out and compared. Marshall Stability and Indirect Tensile Strength (ITS) tests are carried out for bituminous mixes. The results are compared and analyzed to determine the optimum bitumen content (OBC) and percentage of plastics to be used. The Marshall Stability value of PMB increased by 69.65% to that of the stability value of the unmodified binder. ITS value of the unconditioned specimen increased up to 0.70 times higher than the ITS value of the unmodified binder. For the conditioned specimen, it increased to 1.50 times higher than the ITS value of the unmodified binder. The optimum percentage of plastic to be used is found to be 3% by weight of bitumen. These overall results obtained showed that the PMB exhibited significantly higher effectiveness in terms of strength, durability, and thus performance as bituminous pavement.

Polycyclic aromatic hydrocarbon sorption and bacterial community composition of biodegradable and conventional plastics incubated in coastal sediments

Resistant to degradation, plastic litter poses a long-term threat to marine ecosystems. Biodegradable materials have been developed to replace conventional plastics, but little is known of their impacts and degradation in marine environments. A 14-week laboratory experiment was conducted to investigate the sorption of polycyclic aromatic hydrocarbons (PAHs) to conventional (polystyrene PS and polyamide PA) and bio-based, biodegradable plastic films (cellulose acetate CA and poly-L-lactic acid PLLA), and to examine the composition of bacterial communities colonizing these materials. Mesoplastics (1 cm2) of these materials were incubated in sediment and seawater collected from two sites in the Gulf of Finland, on the coast of the highly urbanized area of Helsinki, Finland. PS sorbed more PAHs than did the other plastic types at both sites, and the concentration of PAHs was consistently and considerably smaller in plastics than in the sediment. In general, the plastic bacterial biofilms resembled those in the surrounding media (water and/or sediment). However, in the sediment incubations, the community composition on CA diverged from that of the other three plastic types and was enriched with Bacteroidia and potentially cellulolytic Spirochaetia at both sites. The results indicate that certain biodegradable plastics, such as CA, may harbour potential bioplastic-degrading communities and that PAH sorption capacity varies between polymer types. Since biodegradable plastics are presented as replacements for conventional plastics in applications with risk of ending up in the marine environment, the results highlight the need to carefully examine the environmental behaviour of each biodegradable plastic type before they are extensively introduced to the market.

The Effect of Heat Input on the Compression Strength and Durability of Press-formed Paperboard Trays

Press-forming is a process, which is used for manufacturing containers, for example plates or trays from fibre-based materials, such as paper or paperboard. These materials offer a renewable alternative for oil-based plastics in applications, such as food packaging. In many applications, such as food packaging the material is coated with plastic layer or other materials. The stability and mechanical strength of the trays manufactured from these composite materials is highly important to ensure the functionality of the packages in production processes and logistics. Based on previous work it is known that heat has a significant effect on the formability of the materials. However, the effects of heat input on the stability after manufacturing has not been yet researched.The objectives of the paper were to investigate the effect of heat input and the presence of the plastic coating, based on the dwell time and the heating temperature, on the compression strength of the formed trays and the durability of the tray corner area. A series of experiments was performed using an extrusion-coated three-layer paperboard. The manufactured trays were analysed and the strength values were quantified experimentally. The experiments were performed on coated and uncoated paperboard to investigate the effects of the polymer layer.The results show the effect of the heat input on the tray properties. Based on the results, suggestions for process parameter optimization are given.

Recent developments in non-biodegradable biopolymers: Precursors, production processes, and future perspectives.

During the last decades, biopolymers experienced a renaissance. The increasing limitation of fossil resources in combination with a public demand for environmental-friendly and sustainable processes has led to the formation of a market for biobased plastics. Especially non-biodegradable bioplastics are very interesting materials, as they combine the benefits of reduced carbon footprint during production and increased resource efficiency with the persistence to microbial degradation. Consequently, persistent biomass-derived plastic materials are highly promising to substitute conventional fossil-based plastics in applications, which require durability and longevity. Non-biodegradable bioplastics derived from renewable resources represent 57% of all bioplastics with partially biobased polyethylene terephthalate currently leading the market, followed by biobased polyamides and fully biomass-derived polyethylene. An exceptional biopolymer with thermoplastic properties was discovered only two decades ago, when-for the first time-polythioesters were synthesized by microbial fermentation. Though synthesized by bacteria, it turned out that polythioesters are non-biodegradable by microorganisms in contrast to all other biopolymers and thus, represent a novel non-biodegradable bioplastic material. This review gives an overview about the recent development and progress regarding bioplastics with special focus on persistent bioplastics. We describe the generation of the respective monomers from biomass-derived substrates and summarize the current status of production, which range from the laboratory-scale up to large-scale industrial processes.

Just One Word: Plastics

Arguably the most resonant moment in any American movie of the past thirty years occurs in the opening scene of The Graduate, when a Babbittish family friend confronts the film's eponymous hero and offers him unsolicited advice about his postcollegiate career. I just want to say one word to you. Just one word, he intones portentiously: plastics. Audiences howled and the line instantly passed into the folklore of late-twentieth-century America. With its connotations of the imitative, the shoddy, the unnatural, and the inauthentic, this single word seemed to condense all the disquiets that were coursing through American culture in 1968, the year of the film's release. And yet, of course, at the very moment that audiences were hooting at this synecdoche for contemporary culture, they were also using more and more of the stuff itself, so much so that in its omnipresence plastic had paradoxically become nearly invisible. Their infants were swaddled in polyvinyl chloride pants to keep diapers from leaking, their older schoolchildren sat at imitation wooden desks of melamine-phenolic laminate, and they themselves dressed in polyester-blends. At home vegetables maintained crispness in polystyrene drawers, while elsewhere in the refrigerator styrofoam containers sheltered eggs and milk was stored in polyethylene bottles. After meal preparation, commonly on a Formica surface and perhaps in a tetrafluoroethylene Teflon saucepan, leftovers could be stored in a Tupperware container or discarded into a polypropylene garbage can. Such an inventory of plastic's applications was almost infinitely extendible. By 1979 more plastic than steel was being produced in the United States, and this measure only gauged weight; a volume measurement would have made plastic's margin exponentially greater. Practically no branch of human activity escaped plastic's grasp, and it is impossible to overestimate the degree to which it has transformed the material structure of everyday life in the 125 years since its first contrivance. In American Plastics: A Cultural History Jeffrey L. Meikle undertakes to chart this transformation and, as his subtitle indicates, to explore its effects on culture and consciousness. He makes a convincing case that the half-century