Reactive copolymerization of various monomers based on lactams and lactones in a twin-screw extruder

The synthesis of polyamide-polyester-based diblock, triblock, and random block copolymers was carried out in a modular, corotating twin-screw extruder via reactive extrusion. omega-Lauryllactam (LA), epsilon-caprolactam (CA), and epsilon-caprolactone (CL) were used as monomers for the synthesis of the copolymers in the twin-screw extruder. Generally, CL was added downstream. Sodium hydride was the initiator, and N-acetylcaprolactam was the coinitiator. The syntheses of poly(LA-b-CL), poly(LA/CA-b-CL), and poly(LA-b-CA-b-CL) were attempted. Poly(LA/CA-b-CL) was a random LA-CA copolymer with a block of CL. The simultaneous feeding of LA and CA with the initiator systems was added to the first hopper of the twin-screw extruder, and the addition of CL downstream to a second hopper (without the initiator) was used to form this block copolymer. The thermal, mechanical, rheological, and structural properties of the various copolymers were investigated and compared with those of the homopolymers. (c) 2005 Wiley Periodicals, Inc.