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Self-healing polymer is a kind of functional polymer materials that can repair scratches, cracks and other mechanical damage, whose unique self-healing ability is of great significance for prolonging the life of materials. Eigen self-healing polymers have become the focus of current research due to their advantages of mild healing conditions and repeatable healing. In this paper, the preparation technology and properties of self-healing elastomers were reviewed, which provided guidance for the preparation of polymers with high repair efficiency and pointed out its future development trend. The self-healing polymer materials based on Diels-Alder reaction, metal bond, hydrogen bond, ionic bond, disulfide bond, etc., are mainly introduced, and their preparation process, healing mechanism and healing properties are reviewed. Although much progress has been made in self-healing elastomers based on different dynamic bonds, the development of materials with high repair efficiency remains a huge challenge. In this paper, various repair pathways of self-healing elastomers were reviewed, which provided guidance for the balance between repair and mechanical properties. The development of inherently self-healing polymers was also prospected.

Ceramic additive manufacturing allows the fabrication of small series of complex parts without the high costs of molds usually associated with traditional ceramic processing. Although research into ceramic 3D printing by all technologies started back in the 90s, its industrial application is still quite restricted when compared to polymers and metals, which is related to the limited availability and costs of equipment and materials for such applications. This review examined the advantages and limitations of each process (binder jetting, direct ink writing, directed energy deposition, fused deposition, material jetting, selective laser sintering, selective laser melting, and vat photopolymerization), discussing their particularities. It also summarized the commercially available 3D printers and raw materials for ceramic processing, pointing out to trends and challenges of each technology.

Polymer composites play a significant role in developing flame retardants to prevent fire accidents. The current work aims at investigating the flame retardancy of vinyl ester resins (VER) reinforced with nanotitania (nano-TiO 2) nanofiller. The surface functionality of nano-TiO 2 was modified by adding Si and N 2 to improve its flame retardancy. The chemical structure and thermal stability of nanocomposites were studied using Fourier-transform infrared spectroscopy (FTIR) and Thermogravimetric analysis (TGA). Peaks of Si and N 2 in the modified TiO 2-VER nanocomposite and weight loss of the modified composite confirmed the addition of Si and N 2. The tensile strength results have shown that modified TiO 2-VER nanocomposites didn't make any significant impact on the tensile strength in comparison with pure VER. The flammability and thermal stability behaviors of these nanocomposites are evaluated using microscale combustion calorimetry (MCC). At high percent loading of nanofiller, the normalized heat release capacity (HRC) of modified TiO 2-VER nanocomposites was decreased by 27.7%, whereas the HRC of unmodified TiO 2-VER nanocomposites was only reduced by 9.8%. Also, the normalized total heat release of modified nanofiller based PNC was found to be 21.4%, whereas the unmodified PNC was 12.4%.

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