Hot-mould foaming of modified hemicelluloses and hydroxypropyl methylcellulose

Abstract

Plastics are a material group which have revolutionized the materials industry during the past century. However, the often fossil origin and littering of the material is problematic. Therefore, this study aims at exploring natural polymers, such as cellulose derivatives and hemicelluloses from different botanical origins, and demonstrate the possibility to use these polymers in a foaming application. The hemicelluloses were chemically treated in order to enhance their performance and foams with ratios as high as 4:1 of hemicellulose and the cellulose derivative, respectively, were successfully produced by a hot-mould foaming technique. The foams were found to be thermally stable up to about 280°C. The chemical modifications were confirmed by Fourier transform infrared (FTIR) spectra and the foams were evaluated with regard to their liquid absorption capacity as well as their density. After 1 min the best foam absorbed 12.5 g/g of liquid and after 30 min soak time and centrifugation the foams had absorption capacities between 2 and 5 g/g. All foams exhibited densities below 0.1 g/cm 3. In both the absorption test and density evaluation, the foams produced from mainly hemicellulose performed in a similar way as the reference foams based only on the cellulose derivative, which is considered an impressive result since cellulose is often reported to have superior properties to hemicelluloses.

Review on Polysaccharides Used in Coatings for Food Packaging Papers

“…Xylitol and mannitol derived from xylan and mannan are high-value commercial products widely used as alternative sweeteners in food and pharmaceutical industry [90]. Others oligosaccharides compounds extracted from hemicelluloses have been used as prebiotics in food and feed industry [91][92][93].…”

Extrusion of Porous Protein-Based Polymers and Their Liquid Absorption Characteristics

“…These absorbent materials have most frequently been obtained through lyophilization where the material is frozen and the water crystals being templates are sublimated in order to generate porosity [19,20]. Hemicellulose-and protein-based foams have shown a liquid absorption capacity of 12.5 and 32 g/g, respectively, demonstrating their potential to replace their petroleum-based counterparts [20][21][22]. The absorption capacities for such bio-based foams have been within the range of those for fossil-based absorbent polymers (>10 g/g) [23].…”