Study On Properties Of HPM Modified Cyanate Resin And Its High Modulus Carbon Fiber Composites

The fiber reinforced polymer matrix composites have been widelyused in the aerospace field, military field and so on. Cyanate ester (CE)resin monomer possesses symmetrical and rigid molecular structure. Thecuring product can form a network structure with symmetrical triazine ring,which gives it excellent mechanical properties, such as high heat resistance,low moisture absorption, good processing manufaturability and uniquedielectric properties. These excellent comprehensive performances make ita high-performance resin matrix. But the drawbacks of high curingtemperature and brittleness have limited its fabrication and application. Themodification of CE resin can reduce its curing temperature and improve itstoughness, and broaden the scope of its application.In this thesis, N-(4-hydroxylphenyl)maleimide is synthesized tomodify CE resin. The curing schedule, curing kinetics and curingmechanism of the modified resin are studied by DSC analysis. Thereactions and performances of the different components of the modifiedresin are studied. The composites based on comprehensive optimal performance of modified resin and high modulus carbon fiber are manufactured and tested.The study found that HPM can catalyzes the curing reaction of CE resin, make its curing temperature reduced9℃.The curing schedule is160℃/Lh,200℃/3h,240℃/lh. The curing kinetic equation da/dt=3.196xl08exp(-85800/RT)α0.033(l-α)10747can describe the modified system of the curing process. The performance results of HPM-CE curing resin show that mechanical properties improved, but its dielectric properties, moisture absorption property and heat resistance property declined slightly. When CE:HPM=5:1, the modified resin possesses the optimal comprehensive properties. Flexural strength and impact strength are increased by45.5%and67.5%respectively, its tensile strength raise to73.2MPa. Modified resin also has good heat resistance, initial thermal decomposition temperature of378.2℃. Modified carbon fiber reinforced polymer (CFRP) have higher interlaminar shear strength(ILSS) than the unmodified CFRP’s, up by9.6%. The mechanical properties of composites decline in the hot and humid environment. But modified CFRP have more retention of ILSS.