Carbon Capture Utilization for Biopolymer Foam Manufacture: Thermal, Mechanical and Acoustic Performance of PCL/PHBV CO2 Foams

Abstract

Biopolymer foams manufactured using CO2 brings a novel intersection for economic, environmental, and ecological impact. PHBV has a low solubility in CO2 while PCL has a high CO2 solubility. In this paper, PCL is used to blend into PBHV and unfoamed and foamed systems are examined. Foaming the binary blends at two depressurization stages with subcritical CO2 as the blowing agent, produced open-cell and closed-cell foams with varying cellular architecture at different PHBV concentrations. Differential Scanning Calorimetry results showed that a reduction in miscibility occurred as the concentration of PHBV increased in PCL matrix, while Scanning Electron Microscopy results showed the occurrence of bimodal cellular properties in some of the foam fractions, which improved their performance properties significantly. The results on the acoustic performance showed limited impact from foaming over the unfoamed blends but mechanical performance of foams showed a significant impact from PHBV presence in PCL. Thermal performance reflected that foams were affected by the blend thermal conductivity, but the impact was significantly higher in the foams than in the unfoamed blends.

Forefront Research of Foaming Strategies on Biodegradable Polymers and Their Composites by Thermal or Melt-Based Processing Technologies: Advances and Perspectives

“…PHBV is biologically compatible and presents higher flexibility, ductility, and toughness than P3HB [351]. Moreover, PHBV shows barrier properties to water and air, making it a potential candidate for disposable packages and other uses [352].…”

“…Polymer blending was also used as a technique to improve some of the properties of PHVB that are important in foaming, such as low melt viscosity and high crystallinity. Examples include blending PHBV with PCL [352,453], which is a semi-crystalline polymer with high miscibility in CO 2 , with PBAT [376], and with PLA [128,251]. Jenkins et al [453] showed that PHBV and PCL are immiscible when blended using mechanical means, but the same blends were miscible when produced using supercritical methods.…”

Opposite Roles of Bacterial Cellulose Nanofibers and Foaming Agent in Polyhydroxyalkanoate-Based Materials

“…In the last few years, different blowing procedures have been used to reduce PHBV's brittleness and production costs [7,25,27,28]. Particulate leaching is a popular technique often used to obtain high-porosity biopolymer foams for biomedical purposes, but it is rarely employed to obtain PHBV foams due to the chlorinated derivatives used as solvents and the extensive washing required by this technique [7,25].…”

“…Particulate leaching is a popular technique often used to obtain high-porosity biopolymer foams for biomedical purposes, but it is rarely employed to obtain PHBV foams due to the chlorinated derivatives used as solvents and the extensive washing required by this technique [7,25]. The use of supercritical (sCO 2 ) or subcritical carbon dioxide as a physical blowing agent has become a preferred option in recent years due to its nontoxicity and nonflammability [28]. PHBV/polycaprolactone blend foams with open and closed cells were obtained using subcritical CO 2 as a blowing agent [28].…”

“…The use of supercritical (sCO 2 ) or subcritical carbon dioxide as a physical blowing agent has become a preferred option in recent years due to its nontoxicity and nonflammability [28]. PHBV/polycaprolactone blend foams with open and closed cells were obtained using subcritical CO 2 as a blowing agent [28]. However, the porosity and open-cell proportion decreased with the increase in the proportion of PHBV in the blends.…”