Biodegradable Poly(ethylene adipate-co-terephthalate) Foam with High Expansion Ratio and Excellent Compression Properties Prepared by Supercritical CO2 Foaming.

In this study, biodegradable porous poly(ethylene adipate-co-terephthalate) (PEAT) foam materials with excellent properties were prepared using supercritical carbon dioxide foaming technology. First, PEAT with varying molecular weights underwent systematic characterization to understand molecular weight's impact on PEAT properties. Subsequently, the effects of different foaming processes and molecular weight on PEAT foam's foaming performance, solubility, compressive properties, cell structure, and degradation behavior were thoroughly investigated. Experimental results confirmed that PEAT exhibits exceptional foaming capability. Uniform and intact cellular structures can be well retained even after complete aging and shrinkage. All PEAT foams exhibited high expansion ratios, with the maximum reaching approximately 36.69 times. However, due to its linear structure and weak melt strength, the PEAT foam experienced significant shrinkage. Carbon dioxide solubility tests revealed that high-molecular-weight PEAT materials demonstrated superior CO2 dissolution capacity. Notably, compared to the low-molecular-weight PEAT foam, the high-molecular-weight PEAT foam exhibits superior compressive strength and compressive modulus. After 10 compression cycles, it retains excellent compressive strength and elasticity. Furthermore, the PEAT foam demonstrates outstanding biodegradability, achieving a weight loss of 64.03% within a 10 day degradation cycle. These results confirm that the PEAT foam produced via supercritical carbon dioxide foaming technology not only achieves ultrahigh expansion ratios and outstanding compressive properties but also aligns with contemporary societal demands for eco-friendliness and cost-effectiveness. This material combines excellent comprehensive performance with practical application potential, offering prospects for further research and engineering implementation.