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Why Reinforced Plastics?
Published in John H. Mallinson, Corrosion-Resistant Plastic Composites in Chemical Plant Design, 2020
There is no doubt that in the future the physical properties of polymers will be improved as we continue to learn to tailor the molecule to suit our desired ends. Tensile strengths will increase, elasticity, where desired, will be improved, and melting or softening points will be raised. Chemical resistance will be enhanced, particularly at elevated temperatures. The crystallization of polymers containing polar groups generally provides a stronger and more heat-resistant material. Chemical cross-linking of the long chains is another method used for strengthening and toughening organic polymers. A third method being continually investigated is the production of long stiff chains that provide a high degree of inflexibility. Phenylenes are under investigation in this regard. It is quite conceivable that combinations of crystallization, cross-linking, and stiff chains may provide additive results [4].
On expected values of some degree based topological descriptors of random Phenylene chains
Published in Molecular Physics, 2023
Zhi-hao Hui, Shamaila Yousaf, Adnan Aslam, Muhammad Ahsan Binyamin, Salma Kanwal
Phenylenes belong to a class of conjugated hydrocarbons consisting of hexagons and squares arranged in a special order. In the phenylene structure, every square is adjacent to a pair of hexagons, and any two hexagons are not adjacent. If every hexagon is adjacent with only two squares, then we obtain the phenylene chain. Due to the presence of aromatic and antiaromatic rings, phenylenes enjoy some unique physicochemical properties. The excellent properties of phenylene chains have attracted the attention of many researchers. For example, many π-electron properties of phenylene are closely related to similar properties of the benzenoid molecule, called its hexagonal squeeze (HS).