Epoxy‐functionalized polysiloxane reinforced epoxy resin for cryogenic application

ABSTRACT The poor cryogenic mechanical properties of epoxy resins restrict their extensive application in cryogenic engineering fields. In this study, a newly synthesized epoxy‐functionalized polysiloxane (PSE) is used to improve the cryogenic mechanical properties of bisphenol‐F epoxy resin. The Fourier transform infrared spectra and nuclear magnetic resonance confirm the formation of epoxy‐functionalized –Si–O–Si– molecular chain. The surface free energy test results show that the PSE has a better compatibility with epoxy resin. The mechanical test results show that the cryogenic tensile strength, failure strain, fracture toughness, and impact strength of epoxy resin is improved significantly by adding the suitable amounts of PSE. Compared to the neat epoxy resin, the maximum tensile strength (196.92 MPa, an improvement of 11.2%), failure strain (2.97%, an improvement of 33.8%), fracture toughness (3.05 MPa·m 1/2 , an improvement of 30.7%) and impact strength (40.55 kJ m −2 , an improvement of 14.8%) at cryogenic temperature (90 K) is obtained by incorporating 10 wt % PSE into the neat epoxy resin. Moreover, the results also indicated that the tensile strength, Young's modulus, and fracture toughness of epoxy resin with the same PSE content at 90 K are higher than that at room temperature (RT). © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136 , 46930.