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Emergence, Chemical Nature, Classification, Environmental Impact, and Analytical Challenges of Various Plastics
Published in Hyunjung Kim, Microplastics, 2023
Mostly thermoplastic with high heat resistance. In other words, they have good mechanical resistance to high temperatures, particularly up to 150°C. PI, polysulfone, polyethersulfone, polyarylsulfone, polyphenylene sulfide, and liquid crystal polymers are high-performance plastics.18
Bisbenzoxazine–Bismaleimide Blends: Thermal Studies
Published in Didier Rouxel, Sabu Thomas, Nandakumar Kalarikkal, Sajith T. Abdulrahman, Advanced Polymeric Materials, 2022
S. Shamim Rishwana, M. M. Thahajjathul Kamila, C. T. Vijayakumar
The bismaleimide (BMI) systems dominate over the other polymer matrices primarily due to their high performance-to-cost ratio and relatively high temperature resistance. They have superior thermal and oxidative stability, low propensity for moisture absorption, and good flame retardance. They offer excellent thermomechanical properties and withstand high stress at high temperatures at which typical phenolics and epoxies as well as most high-performance plastics are unstable. However, their process ability and fracture toughness are not promising. Attempts to reduce brittleness by way of reduction of cross-link density through structural modification, toughening etc. adversely affect the high-temperature performance. There are a few reports on polybenzoxazine containing imide units as part of the molecule. Preliminary investigations on the co-curing of polybenzoxazine containing BMI as part of the benzoxazine molecule have been reported. The objective of the present work is to examine the polymerization and degradation properties of the blends of traditional benzoxazine based on bisphenol-A with extended bismaleimide.
Asphalt Chemistry: An NMR Investigation of the Benzylic Hydrogens and Oxidation
Published in Arthur M. Usmani, Asphalt Science and Technology, 1997
R. W. Jennings, Jacqueline Fonnesbeck, Jennifer Smith, J.A.S. Pribanic
Polymers are made by chemical reactions that link together small molecules, called monomers, to form large molecules with constantly repeating patterns, called polymers. Depending on the monomers, the way the molecules are linked, and the chemical process used in their manufacture, polymers can possess a wide variety of properties. Some are much stronger than steel, others can be made into very lightweight foams. More than ever, high-performance plastics are becoming the materials of choice for use in construction, automotive design, satellites, packaging medical applications, and many other important areas.
Enhanced thermal stability and long-term mechanical durability at elevated temperatures of thermotropic liquid crystal polyester/glass fiber composites
Published in Mechanics of Advanced Materials and Structures, 2022
Ha-Bin Jeon, Gil-Woo Jeon, Soo-Yeon Kim, Ha-Eun Gang, Gyu-Tae Park, Young Gyu Jeong
As industries and products have become more complex and diversified over the past few decades, the demand for high-performance and multi-functional materials has greatly increased, and related research has been extensively continued [1–3]. Engineering thermoplastics (EPs), which are high-performance plastics suitable for structural and mechanical parts, are also being continuously researched and developed to replace heavy metallic or inorganic parts in the automobile, aerospace, electric, and electronic industries [4]. They can be classified into general-purpose EPs with heat resistance of more than 100 °C and super EPs with heat resistance at elevated temperatures above 150 °C. Thermotropic liquid crystal polyester (TLCP), which consists of aromatic rings between ester functional groups, is one of the most attractive super EPs because of its superior heat resistance, stiffness, chemical resistance, lightweight, moldability, and excellent balance of these properties [5–9]. TLCP is recently expanding its application to precision electronic components suitable for surface mount technology. For advanced applications of electronic and automobile parts requiring excellent heat resistance and mechanical performance at elevated temperatures, researches on TLCP-based composites and their long-term durability need to be further pursued.