Synthesis and characterization of in situ anionically polymerized p-aminobenzoylcaprolactam using di-and tri-functional initiator systems

Summary p-Aminobenzoylcaprolactam has been polymerized anionically in a two-step process to produce aramide-amide copolymers. Both drawn fibers and unoriented films may be produced using this method. The samples were characterized using FTIR, solution NMR, thermal analysis, viscosity, and mechanical testing. FTIR and NMR revealed the incorporation of both the aramid and amide linkages into the polymer backbone. TGA results gave a lower decomposition temperature than that of both aramide and nylon 6 materials. Intrinsic viscosities averaged 0.5 dL/g for the drawn copolymer samples polymerized by the di-functional initiator. Light microscopy displayed crystalline domains that did not appear to melt even up to 300°C. Mechanical testing showed that the initial moduli of drawn fiber samples to be in the range of 30–80 MPa, while homopolymers of nylon 6 and p-benzamide possessed values of 25 MPa and 2.70×10³ MPa, respectively.