Nanocellulose Stabilized Pickering Emulsion Templating for Thermosetting AESO Nanocomposite Foams

Abstract

Emulsion templating has emerged as an effective approach to prepare polymer-based foams. This study reports a thermosetting nanocomposite foam prepared by nanocellulose stabilized Pickering emulsion templating. The Pickering emulsion used as templates for the polymeric foams production was obtained by mechanically mixing cellulose nanocrystals (CNCs) water suspensions with the selected oil mixtures comprised of acrylated epoxidized soybean oil (AESO), 3-aminopropyltriethoxysilane (APTS), and benzoyl peroxide (BPO). The effects of the oil to water weight ratio (1:1 to 1:3) and the concentration of CNCs (1.0–3.0 wt %) on the stability of the emulsion were studied. Emulsions were characterized according to the emulsion stability index, droplet size, and droplet distribution. The emulsion prepared under the condition of oil to water ratio 1:1 and concentration of CNCs at 2.0 wt % showed good stability during the two-week storage period. Nanocomposite foams were formed by heating the Pickering emulsion at 90 °C for 60 min. Scanning electron microscopy (SEM) images show that the foam has a microporous structure with a non-uniform cell size that varied from 0.3 to 380 μm. The CNCs stabilized Pickering emulsion provides a versatile approach to prepare innovative functional bio-based materials.

New Insights into the Formulation and Polymerization of Pickering Emulsions Stabilized by Natural Organic Particles

“…However, the use of natural organic particles stays scarce, and most related studies were conducted recently, with more than 20 papers being published over the last decade, showing the growing interest in focusing on greener alternatives. Among the particles, papers mainly reference the use of polysaccharides (cellulose 14,[202][203][204][205][206][207][208][209][210][211] , starch 201,212,213 , chitosan 134 ), lignin 214,215 , proteins [216][217][218][219] and microorganisms 134,220,221 (Table 4). (adapted from Tan et al 217 , Lu et al 220 and Gong et al 216 ).…”

“…It should be noted that in the case of polyMIPE and polyHIPE, an additional step consisting in the removal of the dispersed phase is required. Free radical polymerization [205][206][207][208] is the most frequently studied polymerization route, followed by polycondensation 209,214,215 and controlled radical polymerization 14 .…”

Recent Trends of Foaming in Polymer Processing: A Review

“…Compared to bulky polymer materials, polymer foam has many advantages, such as low density, good heat insulation, good sound insulation effects, high specific strength, and resistance to corrosion. At present, polymer foam is one of the most widely used polymer materials and plays a very important role in the polymer industry [1,2,3,4,5,6,7,8].…”

Biobased foams for thermal insulation: material selection, processing, modelling, and performance

“…It should be noted this review paper only focuses on foaming methods which produce structurally stable foams. Methods such as Pickering emulsions 38,39 that produce insulating foams with short lifetimes on the order of days or hours are not discussed here.…”