Self-assembly and amphiphilic behavior of poly(ester)-block-poly(amide) diblock copolymer based on biodegradable poly(butylene succinate) and poly(2-pyrrolidone)

• Published in: European polymer journal 2022-01, Vol.163, p.110961, Article 110961
• Main Authors: Ono, Hideaki, Minamikawa, Hiroyuki, Nemoto, Koji, Yoshida, Masaru
• Format: Article
• Language: English
• Subjects: Biodegradability; Block copolymers; Chloroform; Copolymers; Diblock copolymer; Diffraction; Diffraction patterns; Emulsification; Liquid chromatography; Liquid crystals; Lyotropic liquid crystal; Micelles; NMR; NMR spectroscopy; Nuclear magnetic resonance; Optical microscopy; Poly(butylene succinate); Polyamide 4; Polymer blends; Polymerization; Polymers; Precursors; Segments; Self-assembly
• ISSN: 0014-3057; 1873-1945
• DOI: 10.1016/j.eurpolymj.2021.110961

[Display omitted] •Designing and synthesizing poly(butylene succinate)-block-poly(2-pyrrolidone)•Successful preparation and isolation of PBS-b-PA4 diblock copolymer confirmed.•PBS-b-PA4 exhibited self-assembly and amphiphilic behavior.•Promising candidate as a compatibilizer for PBS/PA4 resin binary blends. In the present study, a novel poly(butylene succinate)-block-poly(2-pyrrolidone) (PBS-b-PA4) diblock copolymer was first designed and synthesized by condensing amino-terminal PBS and carboxyl-terminal PA4 at 100 °C under homogeneous conditions. The PBS-b-PA4 chemical structure was determined by combining nuclear magnetic resonance (NMR) spectroscopy and gel permeation chromatography (GPC) analysis, while the solid-state structure was investigated by wide-angle X-ray diffraction. In addition, the self-assembly behavior of the copolymer was studied by optical microscopy, NMR spectroscopy, and light scattering experiments using appropriate solvents. Both terminal groups of PBS-b-PA4 were well characterized, and the average molecular weight of PBS-b-PA4 was consistent with the sum of the precursors. The diffraction patterns also confirmed the presence of precursors. Micelle-like colloidal particles with an amide segment core and an ester segment corona were eventually observed in chloroform. Additionally, it was revealed that PBS-b-PA4 formed a birefringent and fluid liquid crystalline phase in 1,1,2,2-tetrachloroethane. Thus, the emulsifying property was demonstrated in an immiscible two-liquid solution, indicating that the PBS-b-PA4 diblock copolymer is effective as an emulsifier at a comparable concentration of 1 g L-1. Furthermore, the amphiphilic behavior of PBS-b-PA4 was attributed to the varying solubilities between the ester and amide segments. Thus, PBS-b-PA4 could be a promising candidate as a compatibilizer for PBS/PA4 resin binary blends.