Synthesis of Polyamide 6-block-Vinyl Polymers Using New Polyamide 6 Radical Initiators

Abstract

ABSTRACT:Two polyamide 6 (PA6) radical initiators (PA6ini), AI and AlA types (A: PA6 segment, I: azo group), were prepared from 4,4'-azobis-2-cyanopentanoyl chloride and PA6 prepolymers having controlled average molecular weights. Various PA6-hlock-vinyl polymers were synthesized by radical polymerizations of vinyl monomers, such as styrene, methyl methacrylate (MMA), butyl methacrylate, hydroxyethyl methacrylate and vinyl acetate (VAc) using PA6inis. The polymerizations of MMA proceeded homogeneously in phenol/methanol (4,01/1,01), formic acid and 2,2,2-trifluoroethanol. The overall initiation efficiency of PA6ini (AI type) was 0.11 for the polymerization of MMA in formic acid at 60oC for 24h. Poly(MMA) in the polymer synthesized using PA6ini was dependent on concentration, molecular weight and type of PA6ini. PA6-block-poly(VAc) was synthesized in 2,2,2-trifluoroethanol (TFE), but not in phenol/methanol (4,01/1,01).KEY WORDS Polyamide 6 Radical Initiator / Macroazoinitiator / Block Copolymer / RadicalPolymerization I Vinyl Monomers I Polyamide 6 (PA6) has many industrial applications. Block copolymers from P A6 and other polymers, such as vinyl polymers, polyethers, polyimides and polyesters, were synthesized, expecting new properties.

Polyamide4‐block‐poly(vinyl acetate) via a polyamide4 azo macromolecular initiator: Thermal and mechanical behavior, biodegradation, and morphology

“…The first type involves a three‐step procedure, for example, the synthesis of 4,4′‐azobiscyanopentanoyl lactam, followed by the preparation of the vinyl polymer with a lactam end‐group by radical polymerization and the anionic ring‐opening polymerization of lactam monomers, in this order . The other type of procedure also includes three steps, for example, the preparation of the polyamide prepolymer by anionic ring‐opening polymerization, followed by the synthesis of the azo macromolecular initiator by reacting the polyamide with 4,4′‐azobiscyanopentanoyl chloride, and the radical polymerization of vinyl monomers by the azo macromolecular initiator, in this order . The former type is difficult to apply to polar vinyl monomers such as vinyl acetate (VAc), and both types have the disadvantage of requiring a three‐step procedure for the synthesis of polyamide‐block‐vinyl polymers.…”

Synthesis of an azo macromolecular initiator composed of polyamide 4 and its initiation activity for the radical polymerization of vinyl monomers

“…When 2‐pyrrolidone was polymerized with an initiator containing an azo group, the resulting polyamide 4 containing an azo group (azo‐PA4) was a radical producer and an initiator for the PA4‐ block ‐polyvinyl monomer (Scheme ). Over the last few decades, numerous investigations have been carried out on azo macromolecular initiators synthesized by polycondensation or polyaddition 12–22. Two types of synthetic pathways can be used to synthesize block copolymers: vinyl polymerization followed by ring‐opening polymerization and vice versa.…”