Lightweight construction and optimization of wear resistance and anti-slip performance of bio-based TPU and itaconate composite materials

Bio-based TPU/ItBR microcellular foams via supercritical N₂ foaming replace traditional petroleum shoe materials. • Effects of blend ratio, filler and foaming process on morphology and cell structure are clarified for bio-elastomer blends. • Supercritical N₂ foaming balances low density and high abrasion resistance for shoe sole materials. • Rice husk bio-SiO₂ improves abrasion resistance, refines cells and enhances dry/wet slip resistance. Addressing the challenge of balancing lightness, durability, anti-slip performance, and environmental sustainability in conventional sole materials, this study employs bio-based thermoplastic polyurethane (TPU) and bio-based itaconate rubber (ItBR) as primary constituents. By leveraging supercritical nitrogen physical foaming technology, a novel bio-based composite foaming material tailored for eco-friendly shoe outsoles is synthesized. By systematically varying the TPU/ItBR blend ratio and key parameters of supercritical foaming, we prepared a series of both unfoamed and foamed samples. Utilizing characterization techniques such as differential scanning calorimetry (DSC), X-ray diffraction (XRD), Fourier transform infrared (FTIR), and scanning electron microscopy (SEM), we elucidated the intrinsic structure–activity relationship among the microscopic interface structure, compatibility mechanisms, and macroscopic properties of the composite materials. The research findings indicate that a stable N-H····O=C hydrogen bond interaction can be established between the ItBR and TPU phases. This interaction effectively addresses issues such as weak bonding and performance degradation that commonly arise in composite materials, resulting in a significant enhancement of overall performance. The sample with a ratio of 50:50–10 exhibits the most favorable overall performace. Under foaming conditions at 80 ℃, the dry and wet anti-slip coefficients are 0.60 and 0.35, respectively. Additionally, the tensile strength measures 17.1 MPa, while the wear amount is only 24.54 mm 3 /40 m, indicating exceptional strength, wear resistance, and anti-slip properties. The preparation method employed in this study is straightforward, efficient, environmentally friendly, and low-carbon, effectively addressing the production and application needs for sustainable shoe soles. This approach offers a practical reference for future research, development, and industrial production of high-performance, green, and sustainable footwear materials. Download: Download high-res image (182KB) Download: Download full-size image