A clean and sustainable route towards the design and fabrication of biodegradable foams by means of supercritical CO2/ethyl lactate solid-state foaming

作者：Salerno Aurelio^*; Domingo Pascual Concepcion

来源：RSC Advances, 2013, 3(38): 17355-17363.

DOI：10.1039/c3ra42345j

Polymeric foams are essential elements of our life as they are widely used for applications requiring lightweight materials coupled with good mechanical properties and controlled energy and mass transfer. However, foams are often made of petroleum-derivate non degradable materials and manufactured by means of toxic and often hazardous blowing agents. In this work, a clean and sustainable approach to design and fabricate porous biodegradable poly(epsilon-caprolactone) (PCL) materials via solid-state foaming is investigated. The foaming process was performed by using supercritical mixtures of carbon dioxide (CO2) and ethyl lactate (EL) as non-toxic and environmentally friendly blowing agents. Operating temperatures, in the range of 35-40 degrees C, a small amount of EL (up to 0.2%) and either one or two step depressurization profiles were used to control PCL foaming. The results of this study demonstrate that supercritical CO2/EL binary mixtures are promising safer and sustainable blowing agents to design and fabricate renewable PCL foams at relatively low temperatures and with density as low as 0.2 g cm(-3), mean pore size in the 14-530 mm range and pore density from 3.9 x 10(4) to 1.4 x 10(8) pore cm(-3).

• 出版日期2013