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Recycling of Traditional Plastics
Published in Dhiraj Sud, Anil Kumar Singla, Munish Kumar Gupta, Nanomaterials in Manufacturing Processes, 2023
Narinder Singh, Recep Demirsöz
As for all relatively homogenous plastics, the major problems in PP recycling come from this polymer's simple degradability during its life span and during processing and processing operation. Mechanical stress, heat and ultraviolet radiation significantly alter the morphology and structure thus the properties of PP. The properties most affected by the deterioration phenomena are elongation at break and impact intensity but other effects (e.g., esthetic damage and discoloration and others) must also be addressed. Though its degradation pattern is typical to all synthetic polymers, the effects of thermomechanical degradation and photooxidative on PP are catastrophic because of the presence of the carbon in tertiary form in the chains of polymer.
Introduction to Circular Economy and Recycling Plastics
Published in Rupinder Singh, Ranvijay Kumar, Additive Manufacturing for Plastic Recycling, 2022
Deepika Kathuria, Monika Bhattu
Closed-loop recycling, often known as “upcycling or horizontal recycling,” keeps the recovered plastic materials designed and manufactured qualities the same as their virgin counterparts. As a result, the recycled plastic can be utilized to make the same products as before. However, with the use of different ingredients, the product produced can be completely new. Recycling of PET bottles into new bottles is as an example of closed-loop recycling (Ahvenainen, 2003). Polymers such as polypropylene (PP) and high-density polyethylene (HDPE) can be recycled through this process as the properties remain intact in the manufacturer's products as of the original product (www.exeley.com). On the other hand, the designed and manufactured features of recycled plastic materials are degraded to use the material to generate other products which may be of lower-quality goods than the ones from which they were originally recovered. This process is known as open-loop recycling, also termed “downcycling” or “cascading” (Eriksen et al., 2019). Formation of PET fibers from PET bottles illustrates an example of the open-loop recycling process. Figure 1.3 depicts the closed- and open-loop recycling of PET bottles. Unfortunately, the currently known mechanical recycling processes are limited due to the following reasons: a) cost, b) inconsistency in the product quality, and c) mechanical properties degradation.
Fire Explosion Accident Caused by Static Electricity in a Propylene Plant
Published in Mihir Kumar Purkait, Piyal Mondal, Murchana Changmai, Vikranth Volli, Chi-Min Shu, Hazards and Safety in Process Industries, 2021
Mihir Kumar Purkait, Piyal Mondal, Murchana Changmai, Vikranth Volli, Chi-Min Shu
Polypropylene (PP) is a thermoplastic polymer (partially crystalline and non-polar) belonging to the group of poly-olefins, and is the second-most widely used commodity plastic, with improved hardness and heat resistance similar to polyethylene. The PP was first polymerized in 1951 and was commercialized in 1954 by the Italian chemist, Professor Giulio Natta, in Spain. Due to its high demand in the manufacture of piping systems, medical or laboratory items, and daily household items such as bags, containers, ropes and other wearable items, the global industrial demand for this product increased to 56 million tons in 2018, and is projected to reach 88 million tons in 2026 at a growth rate of 5.7%. In the international market over the past few years, the electronics, computer, and biotechnology sectors under domestic high-tech industries have gained attention. The risk of fire and explosion along with various poisonous gas releases have intensified because of the installation of various high-tech plants in Taiwan. Therefore, an increasing need for such disaster management has emerged which needs to be implemented in high-tech plants (Hsieh, 2014; Li, 2014). The present research explored the fire and explosions caused mainly due to the leakage of acetone involved in high-tech plants with polypropylene (PP) and copper-clad laminates (CCLs) units. The investigation was focused mainly on the space management of the high-tech plants at the fire hazard incident and through the analysis of similar spatial features determined the potential risk of plants (Suardin et al., 2009; Dana et al., 2014).
The role of physicochemical marble processing wastewater treatment sludge in the production of new generation pyrolysis char from waste polypropylene
Published in Environmental Technology, 2023
Merve Sogancioglu Kalem, Afra Ozgan Kurt, Gamze Goktepeli, Vildan Onen, Gulnare Ahmetli, Esra Yel
The increase in consumption results in the increase in the amount of generated wastes and environmental pollution. Plastics are being used as an indispensable part of many industries and they create a significant amount of waste after use. In addition, diverse types of household appliances are thermoplastics and they return as wastes in shorter time periods, especially packaging wastes. The most common types of plastics found in household wastes are polyethylene (PE), polystyrene (PS), polyvinyl chloride (PVC) and polyethylene terephthalate (PET), polypropylene (PP). PP wastes are plastic wastes containing colorants, plasticizers and stabilizers with a decomposition life of 20–30 years. Thermal and thermocatalytic processes can be preferred in the recycling/recovery of these plastic wastes, and so, products with high hydrocarbon content that can be used in different industrial areas can be obtained [1].
Using mussel shell wastes as an additive for the production of thermally improved polypropylene composite monofilaments
Published in The Journal of The Textile Institute, 2021
Cemal Kochan, Figen Selli, Umit Halis Erdogan
Polypropylene (PP) is a well-known and one of the most widely used synthetic polymers in various products such as fibers, films and composites. This is attributed to its low density, low cost, easy processing property, high-tensile strength and excellent chemical stability. However, it has some shortcoming such as low dimensional, and low thermal stability (Erdem et al., 2009; Lewin, 2006; Qian & Lan, 2003). Various types of physical and chemical modifications can be applied to the polymer to overcome properties against these shortcomings. Recently, using organic and inorganic particles as fillers in polymeric materials such as composites, films, and fibers (or filaments) became even more important by providing functional properties to the end-use products and widening the application. Filaments can be also defined as composite or nano-composite depending on the size of the fillers incorporated into the polymer (Erdem et al., 2009; Erdoğan et al., 2015; Kara et al., 2016; Seki et al., 2017).
Dynamic strain rate and relative density effect on compression behavior of PP and PP/PE copolymers foamed by microcellular injection molding
Published in Mechanics of Advanced Materials and Structures, 2020
T. Gómez del Río, J. Rodriguez, D. Arencón, A. B. Martínez
Due to its good ductility and stiffness, moisture, and chemical resistance, PP is one of the most common polymers used. It is also easily processed, versatile, and has a low cost. Nevertheless, PP shows very low impact strength so its use is limited in structural applications. One of the solutions to this problem has been the addition of a second rubbery phase. Modified polypropylenes with different impact modifiers have been studied: for example, blends of propylene–ethylene–diene terpolymer (EPDM) and polypropylene, ethylene/propylene block copolymers (EPR), and styrene–ethylene/1-butene–styrene block copolymers (SEBS). Although a variety of elastomers have been studied, the two first mentioned are the most commercialized due to the low cost of processing [25].