| Abstract: | For reducing the cure temperature and improving the thermal stability and mechanical properties, a thermosetting resin system composed of novolak and bismaleimide (BMI) was developed by reactive blending and using dicumyl peroxide (DCP) as a novel curing agent. Novolak was allylated and reacted with BMI to produce bismaleimide allylated novolak (BAN), and the effect of DCP on flexural, impact and heat distortion temperature of cured resin were investigated. On the basis of improved mechanical and thermal properties at 0.5% DCP contents, the curing behavior of DCP/BAN resin system was evaluated by DSC analysis. Ene, Diels‐Alder, homo‐polymerization and alternating copolymerization which occurred in DCP/BAN resin system were further verified using FTIR at sequential cure conditions from 140 to 200°C. Kissinger and Ozawa‐Flynn‐wall methods were used to optimize the process and curing reactions of DCP/BAN resin system. The results showed that the addition of 0.5% DCP in BAN reduced the curing temperature and time of the modified resin. For evaluating process ability of the modified system, composite samples using polyvinyl acetyl fiber were molded and tested for flexural properties. The resulting samples showed better flexural properties when compared with the composite made with neat BAN. The modified 0.5% DCP/BAN resin system with good mechanical properties and manufacturability can be used for making bulk molding compounds and fiber reinforced composites required in various commercial and aerospace applications. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41829. |
