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Catalytic Conversion Processes
Published in Marcio Wagner da Silva, Crude Oil Refining, 2023
Ortho-xylene is separated from heavy aromatics in another distillation column, while the meta- and para-xylenes are fed to a crystallization process, where a stream is obtained with a high concentration in meta-xylene and the residual stream is directed to an isomerization unit, aiming to promote the conversion of residual meta- and ortho-xylenes in para-xylene. The aromatic production units are normally optimized to maximize the para-xylene production because this is a petrochemical intermediate with higher interest. This compound is raw material to produce terephthalic acid that is used to produce PET (polyethylene terephthalate).
Degradation Studies of Biodegradable Composites
Published in Arbind Prasad, Ashwani Kumar, Kishor Kumar, Biodegradable Composites for Packaging Applications, 2023
Degradation is a change in the chemical body of a polymer chain, which leads to a decrease in the relative molecular mass of the polymer over time by breaking large molecules into fine fragments of different sizes and structures. It is a well-known fact that our current existence would be impossible to maintain without the use of man-made polymers. PET and polyurethane (PU) have grown in popularity. PET is a polymer composed of polyethylene terephthalate (PET) that is commonly used to make flasks and storage tanks, drain channels, water cans and bottles, and beverage containers. As the world’s population has expanded, so has the use of plastic. As a result, plastics have become indispensable in a wide range of products, and they have the ability to enable previously unthinkable feats. Plastics are reshaping the planet. To fully benefit from the merits of polymers, however, their components must be correctly recovered and managed at the moment of termination (Scott G, 1999).
Thermal Properties of Recycled Polymer Composites
Published in R.A. Ilyas, S.M. Sapuan, Emin Bayraktar, Recycling of Plastics, Metals, and Their Composites, 2021
Marwah Rayung, Min Min Aung, Hiroshi Uyama
Polyethylene terephthalate (PET) is one of the most commonly used thermoplastic polymers in packaging industries, monopolizing the bottles market for beverages. It is abbreviated by the resin identification for recycling as code #1. PET is a hard, lightweight, robust and dimensionally stable material. It can withstand high temperatures while maintaining its structural properties. PET can be highly transparent and colorless, but thicker sections are usually opaque and off-white. Depending on its processing and thermal history, PET can exist both as an amorphous and as a semi-crystalline polymer and it can be easily recycled at high temperature. The use of recycled PET (RPET) in place of the virgin PET has been significantly rose up due to its potential recyclability properties (Nisticò, 2020). The chemical structure and thermal properties of the PET is presented in Figure 9.1. Tg and Tm represent the glass transition temperature and melting point of the polymer.
State of art review on the incorporation of fibres in asphalt pavements
Published in Road Materials and Pavement Design, 2023
Shenghua Wu, Ara Haji, Ian Adkins
Polyethylene terephthalate (PET) is widely used in bottles and containers, which is a thermplastic polymer resin of the polyerst family (Wu & Montalvo, 2021). Shredding waste PET bottles result in 1.18–2.36 mm PET strips, which can be added into asphalt mixtures. The melting point of PET fibre is about 290°C. It has the modulus of elasicty of 10.2 GPa, ductility of 20% and tensile strength of 910 MPa. Typical dosages of PET fibres in asphalt mixtures range from 0.2% to 2% by weight of asphalt binders. Most researches focused on the addition of PET fibres to reinforce the asphalt mixtures as a dry method. It is generally found that the addition of PET fibres can improve draindown, Marshall stability, IDT strength and fatigue behaviour by reduced stiffness of asphalt mixtures (Dehghan & Modarres, 2017; Modarres & Hamedi, 2014; Ranadive et al., 2018, p. 7). Agglomeration is found in PET fibre-modified asphalt mixtures, and 2% of PET fibre is maximum dosage (Dehghan & Modarres, 2017).
Mechanical performance of asphalt mixtures using polymer-micronized PET-modified binder
Published in Road Materials and Pavement Design, 2018
José de Arimateia Almeida e Silva, John Kennedy Guedes Rodrigues, Maria Wilma de Carvalho, Lêda Christiane de Figueredo Lopes Lucena, Erinaldo Hilário Cavalcante
Polyethylene Terephthalate (PET) is normally used in fibres for clothing, containers for liquids and foods, thermoforming for manufacturing, and in combination with glass fibre to produce engineering resins. Since late 1990s until 2011, the worldwide production of PET is around 14–60 million tons (Lepoittevin & Roger, 2011) and the annual production of it exceeded 6.7 million tons/year (Kumar, Reedy, & Sasidhar, 2014); therefore an equivalent amount of PET waste was generated (Geyer, Lorenz, & Kandelbauer, 2016). The consumption of PET is creating environmental problems due to its short service life and poor biodegradability (El Mejjati et al., 2014).