High Strength/High Modulus Aromatic Heterocyclic ABA Block Copolymers

摘要

This paper describes our research on the synthesis and properties of ABA block copolymers composed of a rigid-rod (B) block for reinforcement and a flexible coil (A) block as the matrix. In addition to better processability (Ccr), it was anticipated that the block copolymer would have better mechanical strength than those from physical blends of the rigid-rod/flexible coil composition. In the block copolymer, the rigid-rod constituent would be chemically bonded to the flexible coil matrix, while in the physically blended molecular composite the reinforcing rigid-rod polymer is only physically entangled in the matrix. Hence, the translation of stress or strain from the reinforcing rigid-rod molecule in the matrix should be more efficient in the block copolymer than in the physical blend. This would not only provide higher tensile strength, but also fracture toughness and dimensional stability.