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

Abstract

Polyamide 4 containing an azo group (azo-PA4) was synthesized by the ring-opening polymerization of 2-pyrrolidone when 4,4 0 -azobiscyanopentanoyl chloride was used as an initiator. It was possible to control the molecular weight (MW) of the azo-PA4s through the concentration of the initiator to some extent, and the highest weight-average MW obtained was 35 Â 10 3 . To assess the initiation activity of the azo-PA4 for radical polymerization, styrene (St) was used as a vinyl monomer. The azo-PA4 was found to initiate the radical polymerization of St to produce polymers. Analyses by FT-IR spectroscopy, 1 H-NMR, and differential scanning calorimetry after the homopolymers [polyamide 4 (PA4) and polystyrene (PSt)] were removed by Soxhlet extraction showed that the remaining polymer was PA4-block-PSt. Azo-PA4 was also found to have an initiation activity for other vinyl monomers (methyl methacrylate, vinyl acetate, etc.). V C 2012 Wiley Periodicals, Inc. J Appl Polym Sci 126: E425-E432, 2012

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

“…Reagents and starting materials were treated as follows: 2‐pyrrolidone (Kishida Chemical, Osaka, Japan) was distilled under reduced pressure, followed by drying over calcium hydride; sodium (Wako Pure Chemical Industries, Osaka, Japan) was used after removing impurities from the surface; 4,4′‐azobiscyanopentanoyl chloride was prepared by the halo‐de‐hydroxylation of 4,4′‐azobiscyanopentanoic acid (Wako Pure Chemical Industries) with thionyl chloride (Kishida Chemical), as described in an earlier paper; 2,2,2‐trifluoroethanol (Kishida Chemical) and chloroform (Wako Pure Chemical Industries) were used as received; vinyl acetate (Wako Pure Chemical Industries) was purified by distillation. The PA4 compounds containing the azo group (azo‐PA4) were prepared by anionic ring‐opening polymerization of PRN using 4,4′‐azobiscyanopentanoyl chloride as an initiator, as described in the literature …”

“…Modifying the procedure would make it possible to synthesize azo‐PA4 by taking advantage of the low polymerization temperature of PRN and to reduce the number of steps in the synthesis of polyamide4‐block‐vinyl polymers to two. A previous paper has reported the synthesis of azo‐PA4 and its initiator activity for the radical polymerization of vinyl monomers . The synthesis of azo‐PA4 made it possible to polymerize various vinyl monomers and the formation of the block copolymer was confirmed by conducting an experiment using styrene as the monomer.…”

Synthesis of N-methylol polyamide 4: characterization, properties, and biodegradability

“…20 In terms of the design of polymer structures, there have been reports on the synthesis of three-star polyamide 4 and their properties, 12 on the synthesis of polyamide 4 with long-chain fatty acid and their biodegradability, 21 and on the synthesis of a polyamide 4 containing azo group and its initiation ability for vinyl polymerization and subsequent synthesis of polyamide 4-block-poly(vinyl acetate). 22,23 Polyamide 4 is a material with useful characteristics as described above. Therefore, it is important to modify its properties in order to develop a wide range of applications.…”

Synthesis of Multiblock Copolymer Composed of Biodegradable Poly(butylene succinate) and Poly(2‐pyrrolidone): Impact of Each Block Length on the Mechanical Properties

“…The PA4 block unit must exhibit a sufficiently high degree of polymerization (PA unit: > 50). [22,23] A diblock copolymer with a short-length block cannot behave as a resin. [24] Multiblock copolymers are therefore more attractive for the fine-tuning of properties by modulating the degree of polymerization.…”

“…[14] Copolymerization with other components can be used to exploit PA4 and overcome these drawbacks. In this regard, random copolymers, including poly(2-pyrrolidone-co-𝜖caprolactone) [19,20] and poly(2-pyrrolidone-co-𝜖-caprolactam), [21] or diblock copolymers, including PA4-block-poly(olefin), [22] PA4block-poly(L-lactide), [23] and PA4-block-PBS, [24] have been studied. Random copolymers are easily produced, but their T m depends on the proportion of each monomer unit and thus is different from that of the PA4 homopolymer.…”