Cracks may generate in epoxy resins, which can affect the comprehensive property and shorten service life. The problem is expected to be resolved by endowing epoxy resin with self‐healing performance. Herein, a new kind of self‐healing epoxy resin containing both Diels–Alder (DA) bonds and nitrile butadiene rubber (NBR) has been developed. The self‐healing performance and mechanical properties of as‐prepared epoxy resins are investigated by qualitative observation and quantitative measuring. Results reveal that the as‐prepared epoxy resins exhibit excellent self‐healing performance and multiple repair ability, and the self‐healing behavior is based on dual actions of thermal reversibility of DA reaction and thermal movement of molecular chains. Furthermore, the thermoreversible DA bonds contribute much to the recovery of mechanical property, while the incorporated thermoplastic NBR accelerates the whole healing process. The self‐healing efficiency of epoxy resins can be enhanced markedly by introducing thermoplastic NBR. In addition, the self‐healing epoxy resins also exhibit outstanding reprocessing performance, which makes it possible of recycling waste epoxy resin. POLYM. ENG. SCI., 59:1603–1610 2019. © 2019 Society of Plastics Engineers

The research principally consists of the qualitative and quantitative analysis of sound insulation performance of laminate structure. Composite materials have been widely used in aerospace, marine, transportation and other engineering industries due to their light weight, good mechanical properties and high temperature and corrosion resistance. On the Boeing 787 Dreamliner, more than half mass is taken by composite materials which are distributed over the wings, the empennage and the engine nacelles. As the extensive usage of composite laminated plate in the aeronautic domain, people began to focus on their acoustic performance. The mass law was proposed in the end of 19 th century (Rayleigh, 1878). It has been proved that the sound insulation is linearly dependent on the density and excitation frequency. The mass law has been widely applied and validated in different circumstances over the past century. In the middle of 20 th century, the occurrence of the theory of coincidence effect (Cremer, 1942) gave a theoretical explanation of the reduction of the acoustic performance in the middle and high band. These theories have formed the very base of modern acoustics. With the advent of computers, the study of the acoustic properties of materials has entered the era of simulation. The simulation-based studies principally use finite element analysis and statistical energy analysis. For example, the study of point-support plate structure (Shorter et al., 2005), the study of inlaid finite laminated plate (Li and Zhao, 2001) and the study of sound insulation performance of glass fibre reinforced resin-based materials with steel balls inside (Yan and Huang, 2016). Many studies have been carried out on composite laminates materials, while rare conclusion or law of laminate manner constated from researches. At present,