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Open Access Article

2 - A Review of Mechanical Recycling of Polylactic Acid: Challenges and Recent Achievements
Farzane Tabatabaee

The growing use of polylactic acid (PLA) encourages technologists to conduct extensive research into valorization of PLA waste with best quality. In general, mechanical recycling of PLA is one of the most cost-effective recycling methods. However, recycled materials are More

The growing use of polylactic acid (PLA) encourages technologists to conduct extensive research into valorization of PLA waste with best quality. In general, mechanical recycling of PLA is one of the most cost-effective recycling methods. However, recycled materials are commonly used for minor applications due to the inherent thermo-mechanical degradation of the polymer during recycling, which mainly results in chain scissions and intramolecular and intermolecular transesterification reactions. Therefore, it has a negative effect on the molar mass distribution and consequently on the mechanical, thermal and rheological properties of recycled PLA. In this article, a review of recent research on the effects of mechanical recycling on the properties of PLA including structural, morphological, mechanical, rheological and thermal changes was done. Furthermore, a review of three main ways of valorization of recycled PLA including thermal modification, chemical modifications in the presence of stabilizers, chain extenders, branching agents and finally mixing with nanoadditives or with other polymers was done in order to improve the properties of recycled PLA. Moreover, due to the widespread use of natural fibers to improve the performance of PLA, the recyclability of natural fiber-reinforced PLA biocomposites was investigated. Finally, two important applications of recycled PLA in the food packaging and the 3D printing industries were discussed. Manuscript profile

Open Access Article

3 - A Review On Biodegradable Mealworms Mechanism
SeyedAmirHossein Mousavi Aghabagher reza jahan mardi

Every year, an enormous amount of 2.5 million tons of plastic enter the oceans. On land, plastic also accumulates in landfills, beaches and other sensitive ecosystems around the world which has been a huge concern through the years. Recent research has been conducted to More

Every year, an enormous amount of 2.5 million tons of plastic enter the oceans. On land, plastic also accumulates in landfills, beaches and other sensitive ecosystems around the world which has been a huge concern through the years. Recent research has been conducted to show us that one type of worm may help us solve the huge problem of plastic waste. Scientists have discovered that the larvae of a type of worm, Mealworm called Tenebrio Molitor, can include styrofoam and other polystyrenes as well as polyethylene in their diet. Not only do worms go on a styrofoam diet, they say, but the microorganisms in their gut can break down plastics during their digestive process, turning it into carbon dioxide and eventually use it as the nutrients that their bodies need. Biodegradable materials disposed by worms also seem to be used as fertilizer to fertilize and impregnate agricultural soil. We are looking for solutions to implement this discovery in a way that eliminates plastic waste therefore can be a solution to clearer oceans, rivers and the entire environment from the inevitable consequences of plastic accumulation. In this review study, narrations from articles related to the biodegradation of polyethylene, polystyrene and polypropylene have been reviewed. Manuscript profile

Open Access Article

4 - Recycling of Waste Tires
Zahra Khoubi-Arani

Waste tires are the main source of waste rubbers. Their recycling raises environmental concerns due to the high volume of production as well as a very crosslinked and non-biodegradable structure. This leads to finding easy, low-cost, and energy-efficient methods for rec More

Waste tires are the main source of waste rubbers. Their recycling raises environmental concerns due to the high volume of production as well as a very crosslinked and non-biodegradable structure. This leads to finding easy, low-cost, and energy-efficient methods for recycling waste tires. To now, many studies have been devoted to the improvement of conventional recycling methods and the introduction of new ones for the management of waste tires. Methods for recycling waste tires include retreading, incineration, pyrolysis, and grinding. The lifetime of a tire can be extended using the retreading process, in which the old tread is removed and a new one is inserted. The produced energy from the incineration of the waste tire can be used as a fuel source for steam, electrical energy, paper paste, paper, lime, and steel production. In the pyrolysis process, oil, gas, and char are produced through thermal decomposition. The main method of waste tire recycling is grinding for the incorporation of produced particles in the polymer matrices. The ambient and cryogenic grinding are the most conventional methods for grinding waste tires. The size reduction results in a higher specific area and better distribution of rubber particles in the matrix. The produced particles can be used as fillers in asphalt, concrete and glassy polymers. Manuscript profile

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