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It is difficult to recycle classic thermosetting plastics. Although some of them can be reprocessed, the mechanical properties decline linearly after processing. In addition, most thermosetting plastics are not environmentally friendly and difficult to degrade, resulting in a lot of pollution and limiting their practical application potential. In this paper, the prepolymer is synthesized by using castor oil (CO), hydroxyl terminated polydimethylsiloxane (PDMS‐OH), and toluene diisocyanate (TDI). Using 4,4'‐diaminodiphenyl disulfide (ODD) as a chain extender with dynamic disulfide bond and aniline (An) as a blocking agent, polysiloxane‐aminoester (SiCPUO) with recyclable function under DMF induction was prepared. The effect of the amount of rigid chain extender (ODD) containing disulfide bond on the properties of SiCPUO was studied, its heat resistance will first increase and then decrease with the increase of ODD content, especially the mechanical properties are more obvious, this trend has never been reported before; the mechanical properties and recyclability of SiCPUO are tested, and the comprehensive performance of SiCPUO2 is the best, the tensile strength is 0.84 MPa and the elongation at break was 65.81%; the solubility test of different solvents showed that it has recyclability, recovery rate is 95%;the material has self‐healing function, the repair efficiency is up to 95%. [ABSTRACT FROM AUTHOR]

Polyurethane is the main matrix material of polymer damping materials, but the damping temperature range is narrow, the effective damping temperature range does not match the working temperature of the material, and the elastic modulus is sensitive to temperature during glass transition, which is not conducive to safe use in a wide temperature range. In this paper, the polyurethane gradient material with the hard segment content continuously changing along the length direction was designed and prepared by the reaction injection method. Dynamic mechanical analysis (DMA) shows that the gradient structure greatly influences the comprehensive damping performance of polyurethane. While maintaining no significant decrease in mechanical properties, the gradient material extends the effective damping temperature range (TR) from 40.7°C (−32.3 ~ 8.4°C) for component A and 66.6°C (59.5 ~ 126.1°C) for component B to 139.5°C (−20.6 ~ 118.9°C). At the same time, the damping peak remains high (0.48), which is close to the higher damping peak of the B component of 0.56. The elastic modulus (E′) decreases slowly with the increase in temperature, which can better ensure the safety of the material. [ABSTRACT FROM AUTHOR]

In order to improve the flame retardancy and antistatic properties of polyamide 6 (PA6) at as low amount of additives as possible, an integrated‐functional additive was synthesized by 9,10‐dihydro‐9‐oxa‐10‐phosphaphenanthrene‐10‐oxide (DOPO) and multiwalled carbon nanotubes (MWCNTs). The results showed 2 wt% of DOPO‐MWCNTs distributed in PA6 formed an electric network and decreased volume resistivity sharply to 3.1 × 108 Ω cm. In other words, it helped PA6 to get to the percolation threshold of semiconductor. By using of 3 wt% DOPO‐MWCNTs, the severe dripping in burning of PA6 was almost controlled. The possible reason was also ascribed to the network formed by evenly dispersed DOPO‐MWCNTs, which strengthened the char structure and held severe dripping of PA6. As a result, the heat and smoke release were also suppressed obviously. The most important is that CO release was about half cut in CONE test. [ABSTRACT FROM AUTHOR]