Synthesis and properties of polymethylphenylsiloxane modified by aryl acetylene

Polymethylphenylsiloxane was modified by aryl acetylene to improve heat resistance of silicon resin and its composite.The structure of the polymethylphenylsiloxane before and after modified was characterized by FT-IR spectroscopy.The interfacial shear strength,flexural strength and interlaminar shear strength of the composite were tested.The measurement results show that interfacial shear strength of the modified composite at room temperature and 200 ℃ can increase by 3 MPa and 8 MPa respectively;flexural strength of the composite at room temperature and after ablated for 30 min at 500 ℃can reach 349.72 MPa and 301.01 MPa respectively;interlaminar shear strength of the composite is 25.21 MPa at room temperature and 17.43 MPa after ablated for 30 min at 500 ℃.Under the same conditions,mechanical properties of the modified composite are superior to that of polymethylphenylsiloxane.The above results show that the introduction of aryl acetylene can improve heat resistance,interfacial properties of polymethylphenylsiloxane and mechanical properties of glass fiber/aryl acetylene-polymethylphenylsiloxane composite.