Recyclable Self-Healing Polyurethane Cross-Linked by Alkyl Diselenide with Enhanced Mechanical Properties

Abstract

Dynamic structures containing polymers can behave as thermosets at room temperature while maintaining good mechanical properties, showing good reprocessability, repairability, and recyclability. In this work, alkyl diselenide is effectively used as a dynamic cross-linker for the design of self-healing poly(urea–urethane) elastomers, which show quantitative healing efficiency at room temperature, without the need for any catalysts or external interventions. Due to the combined action of the urea bond and amide bond, the material has better mechanical properties. We also compared the self-healing effect of alkyl diselenide-based polyurethanes and alkyl disulfide-based polyurethanes. The alkyl diselenide has been incorporated into polyurethane networks using a para-substituted amine diphenyl alkyl diselenide. The resulting materials not only exhibit faster self-healing properties than the corresponding disulfide-based materials, but also show the ability to be processed at temperatures as low as 60 °C.

Experimental and numerical simulation study on the flow characteristics and optimization of structural parameters of displacement agent in partial pressure tools

“…However, with the increase of the flow space, the flow state of the solution is diffusion‐like. Due to the elasticity of the molecular chain, it can generate an elastic restoring force after stretching, causing the molecular chain to shrink and the overall structure to become compact, with a macroscopic increase in viscosity . From the viscosity curve, it can be seen that in the periodic shearing process, the shearing effect is greater than the elastic recovery effect, which leads to a viscosity reduction of the polymer solution.…”

“…Due to the elasticity of the molecular chain, it can generate an elastic restoring force after stretching, causing the molecular chain to shrink and the overall structure to become compact, with a macroscopic increase in viscosity. [61][62][63][64][65][66][67][68] From the viscosity curve, it can be seen that in the periodic shearing process, the shearing effect is greater than the elastic recovery effect, which leads to a viscosity reduction of the polymer solution. After the accumulation of the shearing effect of the throttling unit, the viscosity of the polymer solution decreases by 6.69%.…”

Organoselenium chemistry-based polymer synthesis

“…After that, in 2019, they synthesized a novel diamino diselenide crosslinker via the ring opening reaction of γ-butyroselenolactone and postmodification reaction with prepared polyurethane. 197 The obtained polymer also showed better self-healing properties (almost 100%) without heating, a catalyst, special lighting or reprocessing. Other researchers expanded it to waterborne polyurethanes and the materials showed good performance.…”

A Fluorescent Polyurethane with Covalently Cross-Linked Rhodamine Derivatives

“…Previous research has proved that the thermal stability of cross-linked polyurethanes is higher than that of the linear one [ 18 , 19 ]. Network structures also result in improvement of mechanical properties [ 20 , 21 ]. Some works have been devoted to the influence of crosslinker on properties of PU.…”