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Microcapsules with polydopamine composite shell layer were successfully synthesized by functionalizing silica‐modified microcapsules containing isophorone diisocyanate. The components and micromorphology of silica‐modified microcapsules at different reaction periods were studied by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy. The structure of different microcapsules was characterized by FTIR, 1H nuclear magnetic resonance and x‐ray photoelectron spectroscopy. The mechanical performances of different microcapsules were analyzed by nanoindentation technique. The compatibility and self‐healing efficiency of different microcapsules with the substrate were also investigated by the tensile tests. The results showed that the density of the silica‐modified microcapsule shell gradually increased and the mechanical performances were enhanced with the silica source. The hardness and elastic modulus of silica‐modified microcapsules in suitable core fraction (76.5 wt%) were 139.9 MPa and 2.2 GPa, which are 2.3 times and 4.8 times higher than those of untreated microcapsules, respectively. The functionalized modified microcapsules had excellent compatibility with the elastomeric substrate (PU‐PPG2000). At the same time, the self‐healing efficiency of the functionalized modified microcapsules in PU‐PPG2000 was 69.8%, which was 48.9% higher than that of the untreated microcapsules prepared under the same conditions. Silicon modification improved the density of microcapsules, enhancing their mechanical strength. At the same time, functionalization modification improved the interfacial bonding strength of microcapsules, further improving the compatibility with the polymer matrix. Highlights: Microcapsules with different silicon sources are characterized.Microcapsules are functionalized with polydopamine.Individual microcapsules are tested for mechanical strength by nanoindentation.The compatibility of the functionalized microcapsules is excellent.The self‐healing efficiency of modified microcapsules is greater than 70%. [ABSTRACT FROM AUTHOR]

Thermo‐mechanical properties are often the bottleneck for advanced applications of polyurethane (PU) elastomer materials. Carbon materials are emerging as promising reinforcing fillers for polymers due to their superior mechanical and conductive properties. In this study, carbon fiber‐graphene oxide (CF‐GO) multiscale reinforcements are fabricated for improving thermal‐mechanical properties of PU elastomers. To this end, CFs are firstly modified with GO via electrophoretic deposition and subsequently cooperate with free‐dispersed GO sheets in PU matrix. This multiscale reinforcing strategy effectively improved thermo‐mechanical properties and thermal stability of PU elastomer due to the improved CF‐PU interfacial interaction as well as the local stiffening of fiber‐matrix interphase by the dispersed GO sheets. This reinforcing approach also led to a synergistic increase in the thermal diffusivity of PU elastomer due to the formation of interconnected conductive network, in which CFs serve as a conductive framework that connects the free‐dispersed GO sheets. POLYM. COMPOS., 40:E953–E961, 2019. © 2018 Society of Plastics Engineers [ABSTRACT FROM AUTHOR]