One‐pot synthesis of hyperbranched poly(aryl ether ketone)s for the modification of bismaleimide resins

Abstract

Hyperbranched poly(aryl ether ketone)s with hydroxyl end groups (HBP‐OH) and high degree of branching value (83%) were synthesized via an A2 + B3 approach. The polymerization conditions (e.g., polymerization temperature and time, monomer concentration, stoichiometric ratio of functional groups) were explored to avoid the gelation. Allyl‐terminated hyperbranched PAEKs (HBP‐AL) with low molecular weight (Mn = 3.4 × 103) and narrow polydispersity (PDI = 1.65) were obtained via the etherification of HBP‐OH and it has been used for the modification of bismaleimide (BMI) resins. The prepolymers showed good processibilities with a viscosity below 0.6 Pa s at 110°C, though the viscosities slightly increased as the increase of HBP‐AL contents. The cured BMI resins showed high glass transition temperatures (Tg > 320°C) and good thermal stabilities (Td > 400°C, both in nitrogen and air). It is inspiring to note that the incorporation of HBP‐AL into BMI matrix results in a significant enhancement of toughness without any noticeable loss in modulus, processibility, and Tg. POLYM. ENG. SCI., 54:1675–1685, 2014. © 2013 Society of Plastics Engineers