Foaming Poly(vinyl alcohol)/Microfibrillated Cellulose Composites with CO₂ and Water as Co-blowing Agents

Abstract

We investigated the continuous extrusion foaming of poly­(vinyl alcohol) (PVOH)/microfibrillated cellulose (MFC) composites using supercritical carbon dioxide (scCO2) as the blowing agent. First, the as-received PVOH pellets were compounded with water to decrease their melting point. Then, they were compounded with an MFC solution to prepare the sample. Both scanning electron microscopy (SEM) and environmental scanning electron microscopy (ESEM) showed that the MFC dispersed well in the PVOH/MFC composites. Differential scanning calorimetry (DSC) results showed that adding MFC affected the thermal behavior. This, in turn, affected cell nucleation and cell growth phenomena during foam extrusion. Water also acted as a co-blowing agent, together with scCO2, in creating biodegradable polymer foams with a uniform cell structure and a high cell density. The effects of the MFC content, scCO2 content, and die temperature variations on the cell density and cellular morphology of the PVOH/MFC composite foams were examined systematically.

Crosslinked poly(vinyl alcohol) composite films with cellulose nanocrystals: Mechanical and thermal properties

“…Poly(vinyl alcohol) (PVA), a nontoxic water soluble polymer, has been widely used in many applications, such as drug delivery, adhesives, packaging, heavy metal ions absorption, and acoustic noise reduction, due to its biocompatibility, biodegradability, chemical resistance, and good oxygen barrier properties . However, the poor mechanical properties of PVA limit its use .…”

Non-isothermal crystallization behaviors of poly(lactic acid)/cellulose nanofiber composites in the presence of CO2

“…Among these, CNFs have been highlighted recently as additives or reinforcement in various polymer systems to tailor the performance of the polymer matrix [9,11,[44][45][46][47][48][49]. CNFs are long, flexible, and entangled cellulose fibrils of 20-90 nm in diameter and several micrometers in length [50,51].…”

Thermoplastic foaming mechanism and Pb2+ adsorption of poly(vinyl alcohol)/shell powder porous composite

“…Cell density (cell/cm 3 ) was assessed according to the following formula equation: …”