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Environmental concerns related to the implementation of circular economy has led to the development of new generations of materials. Interest in polymer composites reinforced with natural-organic/inorganic fillers is growing. Producers of polymer composites convert their production to optimize and replace traditional products with new ones with a high content of bio, recyclable materials, for sustainability and responsible actions. Research and industrial awareness are focused on ecological composites based on natural fillers from food production and aquaculture waste due to their low cost and high availability. This work aims to test "green" dynamically vulcanized thermoplastic polymer composites based on PE/PE-g-MA/EPDM reinforced with functionalized seashell waste, resistant to high temperatures for specific products used in the food, pharmaceutical and electronics industries. Seashell waste contains a high percentage (95-97%) of CaCO3 and will be ground to sizes of 100-500nm and functionalized in controlled conditions by silanization for compatibility with the polymer matrix. These composites will have characteristics such as resistance to microorganisms, at high temperatures for long working time and eco-friendliness derived from the use of seashell waste and the recycling of products injected from these materials. There will be a major impact on society due to the solutions that will be offered for reintegration into the natural circuit by increasing the degree of biodegradability after the end of the products' life cycle. [ABSTRACT FROM AUTHOR]

The objective of the circular economy is to definitively change the way in which we produce and consume, it consists of doing more with less, and it brings us back to simplicity, trying to break the dependence: production-consumption of raw materials, making the most of each material and extending its useful life. Through eco-design, it seeks to generate circular products that allow the easy separation of all materials, providing new ways of their management and processing to avoid elimination at the end of their useful life so that they can be recovered to start a new life, "closing the circle". In this study, the carbon footprint generated by the materials and manufacturing processes of the classic shoe vs the "eco-engineered" version was analyzed. The type and source of the materials that make up the footwear are of major influence. Thus, a textile material obtained through recycling was chosen for the upper. The sole used to obtain the footwear product was recycled TPU. The carbon footprint was analyzed with LCA software, GaBi. The LCA was performed on the materials and process for each type of footwear. The Carbon footprint for the eco-engineered version presents values between 65-80% lower than the conventional version. These values depend on the type and amounts of materials and whether this footwear is repaired / recycled. [ABSTRACT FROM AUTHOR]

In this paper were obtained waste/polymeric nanocomposites - polyamide waste (PAW) and polystyrene (PS), compatibilized with maleic anhydride grafted polystyrene, and reinforced with carbon nanofibers (CF). PolyamideWaste / polystyrene (PAW / PS) composites are studied because both components are relatively cheap, with beneficial properties, and can be processed by injection. Compatibility of polymer and waste compounds can be achieved by adding a grafted copolymer, the segments of which have physical or chemical affinity with the two immiscible homopolymers. In this case, maleic anhydride grafted polystyrene (PS-g-MA) was used. Carbon fiber composites are considered to be a new generation of materials with predetermined properties, in this case impact resistance. The combined effects of carbon fiber and compatibilizing polymer (PS-g-MA) have been studied on the structure, and rheological and physicomechanical properties of PAW / PS-g-MA / PS / CF composites. The studied nanocomposites have higher values compared to the control sample -PA, and the Romanian Railway Authority requirements of impact resistance of 5 KJ/m2. Carbon fiber concentrations above 1.5% cause slight drops in impact resistance values, similar to tensile strength, but not lower than control sample values. This conclude that the percentages of carbon fibers in the range of 0.1-1.5% reach the maximum values of physico-mechanical parameters. [ABSTRACT FROM AUTHOR]

This paper presents studies on the development of ecocomposites based on natural rubber and plasticized starch. Natural rubber is the most commonly used elastomer worldwide due to its low cost; it is renewable, non-toxic and shows excellent physical properties. Natural rubber is not used as such but in the form of mixtures which generally contain: fillers, plasticizers, crosslinking agents and other ingredients that provide various features to the final product. Replacement of active fillers in rubber mixtures such as carbon black or silica (which have adverse effects on health) with a biodegradable filler, such as starch provides many advantages, namely: environmental protection, non-toxicity, low density and cost, etc. Ecocomposites were made containing 10 phr, 20 phr, and 30 phr starch, respectively. Starch was plasticized and then incorporated in natural rubber in the roll mill, and then other ingredients were added (compatibilizer, curing agents, antioxidant); the resulting mixtures were cured in an electrical press. The physico-mechanical and chemical characteristics of resulting composites depends on the amount of plasticized starch added to the rubber mixture, as follows: (a) hardness increases while elasticity decreases due to the increased amount of plasticized starch in the mixture, indicating that a reinforced rubber mixture may be obtained by replacing the inorganic filler; (b) tensile strength increases, elongation at break decreases and tear strength has a non-uniform variation; (c) the optimal curing time decreases; (d) mass variation in: water, ethyl alcohol, sunflower oil, 10% glucose solution, 0.9% sodium chloride solution for 22 h has values below 15%. Ecocomposites can be used to obtain products with applications in the food industry, pharmaceutical industry, agriculture, etc. [ABSTRACT FROM AUTHOR]