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      • Open Access Article

        1 - The studying on mechanism, properties and application of shape memory polymers
        Hamidreza Haydari
        Shape memory polymers (SMPs) represent a highly special class of materials. As one representative of the intelligent polymeric systems, these materials gained significant interest in recent years. SMPs are stimuli-responsive polymers, which act as stimulants like light, More
        Shape memory polymers (SMPs) represent a highly special class of materials. As one representative of the intelligent polymeric systems, these materials gained significant interest in recent years. SMPs are stimuli-responsive polymers, which act as stimulants like light, temperature, PH changes, solvent changes, electrical fields or magnetic fields, and their output is strain. Also, these polymers are highly regarded as essential for fundamental research and technological innovation. The present review will provide a short overview with particular attention to structure, mechanisms and applications of SMPs, shape memory effects and, as well as the current developments and concepts for shape memory polymers. The applications of shape memory polymers can be noted in medical industries, commercial industries, S hape memory polymers (SMPs) represent a highly special class of materials. As one representative of the intelligent polymeric systems, these materials gained significant interest in recent years. SMPs are stimuli-responsive polymers, which act as stimulants like light, temperature, PH changes, solvent changes, electrical fields or magnetic fields, and their output is strain. Also, these polymers are highly regarded as essential for fundamental research and technological innovation. The present review will provide a short overview with particular attention to structure, mechanisms and applications of SMPs, shape memory effects and, as well as the current developments and concepts for shape memory polymers. The applications of shape memory polymers can be noted in medical industries, commercial industries, aerospace industries, self-healing polymers, etc. aerospace industries, self-healing polymers, etc. Manuscript profile
      • Open Access Article

        2 - Mini-Review of Self-Healing Mechanism and Formulation Optimization of Polyurea Coating
        Moein Behzadpour Mahdi Hemmatian Damghani
        Self-healing polymers are categorized as smart materials that are capable of surface protection and prevention of structural failure. Polyurethane/polyurea, as one of the representative coatings, has also attracted attention for industrial applications. Compared with po More
        Self-healing polymers are categorized as smart materials that are capable of surface protection and prevention of structural failure. Polyurethane/polyurea, as one of the representative coatings, has also attracted attention for industrial applications. Compared with polyurethane, polyurea coating, with a similar formation process, provides higher tensile strength and requires shorter curing time. The working principle of polyurea self-healing mechanisms is to fill cracks by introducing more healing components, which can polymerize and seal damage in the material. Alternatively, it can also be addressed by encouraging continuous chemical reactions, which can form bonds to close gaps between the separated faces of material due to the damage. In this paper, extrinsic and intrinsic mechanisms are reviewed to address the efficiency of the self-healing process. Furthermore, the extrinsic and intrinsic mechanisms have been compared to attain a better understanding of the advantages and limitations of each mechanism. Moreover, formulation optimization and strategic improvement to ensure self-healing within a shorter period of time with acceptable recovery of mechanical strength are also discussed. The choice and ratio of diisocyanates, as well as the choice of chain extender, are believed to have a crucial effect on the acceleration of the self-healing process and enhance self-healing efficiency during the preparation of polyurea coatings. Manuscript profile