Construction of thermoplastic cellulose esters matrix composites with enhanced flame retardancy and mechanical properties by embedding hydrophobic magnesium hydroxide

Abstract

Biomass‐based composites with renewability and biodegradability have attracted extensive researches, but their applications are hindered by poor mechanical properties and flame retardancy. Cellulose ester matrix composites (CEMC), a kind of biomass‐based composites, were prepared with inorganic crystals as flame retardant and reinforcement. Cellulose acetate oleate (CAO) prepared by mechanical activation‐assisted solid‐phase reaction was used as thermoplastic matrix. Hydrophobic oleate‐magnesium hydroxide (O‐MH), which was surface‐modified with oleic acid, was embedded into CAO to prepare O‐MH/CAO composites by hot pressing. The introduction of oleoyl contributed to favorable thermoplasticity of cellulose ester, resulting in enhanced thermal stability and mechanical properties of CEMC. The uniform dispersion of O‐MH in the CAO matrix via metal–organic coordination increased the mechanical properties and flame retardancy of O‐MH/CAO composites, ascribing to the toughening effect and combustion inhibition effect induced by O‐MH. This study provides a feasible technology for fabricating the CEMC with outstanding thermal stability and mechanical properties.

Effect of the melt flow index of compatibilizer on the melt processing and properties of highly filled magnesium hydroxide/linear low density polyethylene composites

“…5,13,19 Noh et al used hexylphosphoric acid (HPA) to modify the surface of MH nanoparticles to obtain a hydrophobic surface and make MH more uniformly dispersed at a MH content of 50 wt%. 20 Zhang et al found that MH modified with hydrophobic oleic acid could be better dispersed in the cellulose acetate oleate (CAO) matrix compared to unmodified MH and the tensile strength and LOI value were increased by 16.6% and 41.9%, respectively, 21 which was attributed to the improved dispersion of O-MH and the close combination of O-MH and CAO. Liu et al prepared oil-extended styrene-ethylene-butadiene-styrene (O-SEBS)polypropylene (PP) using MH modified with triethoxysilane and polymethyl-vinyl silicone rubber.…”

Study of the effect of different functionalized magnesium hydroxide prepared by mechanochemical method on the flame retardancy and mechanical properties of styrene‐ethylene‐butadiene‐styrene/polypropylene composites

“…[19][20][21] Despite its attractive properties, MH is a hydrophilic material with high interfacial energy and poor compatibility with hydrophobic polymers. [22][23][24] MH particles are highly aggregated in polymer matrix and are difficult to form homogeneous and stable composites. 25 In addition, 60 wt% MH is usually required to ensure the desired flame retardancy of the material, which leads to a dramatic reduction in the processability and toughness of the polymer.…”

“…Magnesium hydroxide (MH) is an environmental, friendly nonhalogenated flame retardant filler, which has been widely studied for its low smoke, nontoxic, noncarcinogenic gas, and other advantages 19–21 . Despite its attractive properties, MH is a hydrophilic material with high interfacial energy and poor compatibility with hydrophobic polymers 22–24 . MH particles are highly aggregated in polymer matrix and are difficult to form homogeneous and stable composites 25 .…”

“…The average particle size of OA‐treated MSH was reduced by 63.7% and had good lipophilic properties. Zhang et al 23 used the mechanochemical method to prepare cellulose acetate oleate as a thermoplastic matrix, which reacts directly with the esterifying agent under solvent‐free conditions, greatly reducing reaction time and cost. Therefore, for chemical synthesis and material miniaturization, the mechanochemical method is a viable, effective and cost‐saving method.…”

Effect of oleic acid on improving flame retardancy of brucite in low‐density polyethylene composite

“…Meanwhile, OA reacted with brucite, magnesium oleate was formed on the surface of brucite. The presence of magnesium oleate can reduce the surface polarity of brucite and promote the homogeneous dispersion of brucite in the LDPE matrix, which also can improve the flame retardancy of LDPE composite 44,45. 4.7 | Mechanical properties of LDPE/ brucite composites…”