Effect of degree of substitution on the microphase separation and mechanical properties of cellooligosaccharide acetate-based elastomers

• Published in: Carbohydrate polymers Vol. 316; p. 120976
• Main Authors: Katsuhara, Satoshi, Sunagawa, Naoki, Igarashi, Kiyohiko, Takeuchi, Yutaka, Takahashi, Kenji, Yamamoto, Takuya, Li, Feng, Tajima, Kenji, Isono, Takuya, Satoh, Toshifumi
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 15.09.2023
• Subjects: Biodegradability; Cellulose acetate; Mechanical properties; Microphase separation; Self-assembly; Thermoplastic elastomer; PS; PLA; E; Biodegradability; χ; TPE; AFM; DP; εb; CDP; DS; Ð; Microphase separation; Tg; THF; DSC; FFT; PDL; Thermoplastic elastomer; αG1P; WAXD; BCC; Cel–C≡CH; Mechanical properties; TODT; BCP; AcCelx; SAXS; TGA; SEC; MALDI-TOF MS; Self-assembly; FWHM; HEX; SEM; Cellulose acetate; σb
• ISSN: 0144-8617; 1879-1344
• DOI: 10.1016/j.carbpol.2023.120976

Thermoplastic elastomers (TPEs) have long been used in a wide range of industries. However, most existing TPEs are petroleum-derived polymers. To realize environmentally benign alternatives to conventional TPEs, cellulose acetate is a promising TPE hard segment because of its sufficient mechanical properties, availability from renewable sources, and biodegradability in natural environments. Because the degree of substitution (DS) of cellulose acetate governs a range of physical properties, it is a useful parameter for designing novel cellulose acetate-based TPEs. In this study, we synthesized cellulose acetate-based ABA-type triblock copolymers (AcCelx-b-PDL-b-AcCelx) containing a celloologosaccharide acetate hard A segment (AcCelx, where x is the DS; x = 3.0, 2.6, and 2.3) and a poly(δ-decanolactone) (PDL) soft B segment. Small-angle X-ray scattering showed that decreasing the DS of AcCelx-b-PDL-b-AcCelx resulted in the formation of a more ordered microphase-separated structure. Owing to the microphase separation of the hard cellulosic and soft PDL segments, all the AcCelx-b-PDL-b-AcCelx samples exhibited elastomer-like properties. Moreover, the decrease in DS improved toughness and suppressed stress relaxation. Furthermore, preliminary biodegradation tests in an aqueous environment revealed that the decrease in DS endowed AcCelx-b-PDL-b-AcCelx with greater biodegradability potential. This work demonstrates the usefulness of cellulose acetate-based TPEs as next-generation sustainable materials. [Display omitted]