Electrospinning of Polyhydroxyalkanoate and Cellulose Acetate Blends to Obtain Elastomeric Fibrous Materials

Abstract

The development of sustainable elastomeric materials is an important step toward reducing the environmental impact of conventional synthetic rubbers. In this study, elastomeric electrospun materials were fabricated from blends of amorphous polyhydroxyalkanoate (aPHA) and cellulose acetate (CA) at three compositions (50/50, 75/25, and 90/10). The influence of fiber morphology and interfiber bonding on the mechanical response was investigated. Neat aPHA showed rubber-like behavior but poor dimensional stability after electrospinning. Incorporating CA improved structural stability, thermal resistance, tensile strength, and Young’s modulus. The 90/10 (aPHA/CA) blend retained a hyperelastic response, consistent with the classical Ogden and Mooney–Rivlin strain-energy models, while improving processability. Morphological analysis during stretching–relaxation cycles revealed a bimodal fiber diameter distribution, originating from axial fiber thinning and perpendicular fiber compression due to interfiber fusion points. A permanent diameter increase of perpendicular fibers (∼20%) was observed after the first cycle and stabilized upon repeated deformation. Fitting of uniaxial stress–strain data to Ogden and Mooney–Rivlin functions confirmed that pure aPHA and the 90/10 blend possess rubber-like properties, whereas the 75/25 composition did not. The biodegradation analysis supports the sustainable nature of the developed rubber-like materials, with all blends exhibiting full biodegradation in compost within 37 days. These results show that controlled CA incorporation regulates interfiber bonding and structural stability, enabling the design of fully biobased electrospun elastomeric materials.