| Abstract: | Nylon‐6‐b‐polyimide‐b‐nylon‐6 copolymers were prepared by first synthesizing a series of imide oligomers end‐capped with phenyl 4‐aminobenzoate. The oligomers were then used to activate the anionic polymerization of molten ϵ‐caprolactam. In the block copolymer syntheses, the phenyl ester groups reacted quickly with caprolactam anions at 120 °C to generate N‐acyllactam moieties, which activated the anionic polymerization. In essence, nylon‐6 chains grew from the oligomer chain ends. All of the block copolymers had higher moduli and tensile strengths than those of nylon‐6. However, their elongations at break were much lower. The thermal stability, chemical resistance, moisture resistance, and impact strength were dramatically increased by the incorporation of only 5 wt % polyimide in the block copolymers. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 4247–4257, 2000 |
