Green fabrication of poly (butylene succinate)/halloysite nanotube open-cell foams with ultra-high foaming and adsorption performance

Ecological balance and human health have been greatly impacted by the environmental effects of oil spill pollution. In order to prepare an environmentally friendly, efficient, potential promising adsorbent for coping with the oil spill pollution, herein, biodegradable poly (butylene succinate) (PBS) open-cell foams were prepared by supercritical CO₂ foaming in the presence of a chain extender and tubular halloysite nanotube (Hal). The unique open-cell structure of PBS foams and the special functional groups on the surface of Hal enabled branched PBS (BPBS)/Hal open-cell foam to efficiently remove oil contaminants and keep excellent mechanical properties. The torque curve and Fourier transformation infrared spectra results showed that the chain extension modification of PBS was successful after adding CE. Meanwhile, the rheological properties and crystallization behaviors of all PBS samples were analyzed by rheometer, differential scanning calorimetry, polarized optical microscopy. It was found that the storage modulus and crystallinity of PBS samples were improved with the increase of Hal content. The obtained BPBS with 0.75 phr of Hal (BPBS/Hal3) open-cell foam exhibited the highest volume expansion ratio (64 times) and adsorption capacities up to 47 g/g carbon tetrachloride (CCl₄) among all the prepared foams. Furthermore, Hal addition enhanced the mechanical properties of BPBS/Hal open-cell foams, resulting in a specific compressive strength increase of 608.4 %. Moreover, BPBS/Hal3 open-cell foam continued to achieve an adsorption capacity of 46 g/g CCl₄ (97.8 % of the initial value) after 10 adsorption cycles. This study not only presents a green and straightforward approach for preparing high-porosity biodegradable polymer open-cell foams but also offers a potentially promising solution for maintaining a green and low-carbon ecological environment without oil spill pollution.