Processing and rheological properties of polyol/cellulose nanofibre dispersions for polyurethanes

Impact of physico‐chemical properties of nanocellulose on rheology of aqueous suspensions and its utility in multiple fields: A review

“…Treatment • Bio-compatible bio-ink assisted the cell encapsulation at 5 million cells/mL cell density. [139] carried out in the present section makes clear the emerging and cutting-edge applications of NCs as rheology modulators in the coating [117] and paint industries [118] as well as a rheology modulator for cement, [119] composites, [118,[120][121][122] electronic devices, [122][123][124][125] cosmetics, foods, [117,[126][127][128][129][130] drilling fluids, [122,131] and so forth. The superior mechanical, shear thinning, and bio-compatible/non-cytotoxic qualities of NC have also piqued researchers' attention in developing 3D bio-printing materials for creating viable living human organs/tissues.…”

“…[ 84,120–149 ] Some of the top‐notch characteristics that specifically define the distinctive rheological features of NC suspensions and their ability to act as rheology modifiers in diverse applications include their large water retention/holding potential, remarkable shear thinning behavior, their capabilities to align at high shear rates, thickening impact, and their capacity to form thixotropic frameworks that excellent restoration phenomena. The literature review carried out in the present section makes clear the emerging and cutting‐edge applications of NCs as rheology modulators in the coating [ 117 ] and paint industries [ 118 ] as well as a rheology modulator for cement, [ 119 ] composites, [ 118,120–122 ] electronic devices, [ 122–125 ] cosmetics, foods, [ 117,126–130 ] drilling fluids, [ 122,131 ] and so forth. The superior mechanical, shear thinning, and bio‐compatible/non‐cytotoxic qualities of NC have also piqued researchers' attention in developing 3D bio‐printing materials for creating viable living human organs/tissues.…”

Dispersion engineering of cellulose nanofibres in polyols: for controlled microstructure of high-performance polyurethane foam

“…The CNF/polyol dispersions are prepared using a sucrose/ glycerol-initiated polyether polyol (Voranol TM 446) and CNF derived from alkali-treated spinifex grass (Triodia pungens) pulp as described in Haridevan et al 6 Tegostab s B 8460 from Evonik and dimethylcyclohexamine (DMCHA) from Sigma-Aldrich were utilised as the surfactant and catalyst. HFCM1, a proprietary blend of HFC245a and HFC365mfc from Applied Polymers, was used as the physical blowing agent, while water was used as the chemical blowing agent.…”

“…The improvement in thermal insulation performance of RPUF is significantly studied by varying high functionality polyols, surfactants, and micro-/nano-scale functional particulate additives. [1][2][3][4] The effectiveness of the particulate additives may be dependent on the method of incorporation, 5,6 quality of dispersion, 4,[7][8][9][10] host polymer compatibility [9][10][11] and loading level 5,[12][13][14] in the RPUF precursors. For example, at an optimal loading, the homogenous distribution of an additive in the polyol media may offer optimal nucleation during foaming, resulting in good microstructure and enhanced performance, whereas the poor distribution (due to less compatible system or inefficient mixing) may lead to re-agglomeration, which in turn may result in damaged microstructure.…”

“…To investigate further, CNF/polyol dispersions prepared by water-assisted dispersion, at levels of 0.028 to 1.12% w/w in polyol (reported in Haridevan et al 6 ), were used to prepare CNF/RPUF nanocomposites (CNF/RPUF) with resultant loading levels of 0.01 to 0.4% w/w. Given that, it is challenging to directly monitor the influence of rheological properties of the CNF/polyol dispersions on the foaming process, the evaluation of curing kinetics of CNF/polyurethane resins (RPUF formulation without blowing agent at an NCO index of 37) using rheological analysis was also attempted to serve as a link between the complex systems of CNF/polyol dispersions and CNF/RPUF.…”