Search

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 (AcCel x - b -PDL- b -AcCel x) containing a celloologosaccharide acetate hard A segment (AcCel x , 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 AcCel x - b -PDL- b -AcCel x 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 AcCel x - b -PDL- b -AcCel x 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 AcCel x - b -PDL- b -AcCel x with greater biodegradability potential. This work demonstrates the usefulness of cellulose acetate-based TPEs as next-generation sustainable materials. [Display omitted] [ABSTRACT FROM AUTHOR]