Polystyrene nanocomposites reinforced with phenyl isocyanate-treated cellulose nanofibers

Abstract

Owing to their superior mechanical and biodegradable properties, application of cellulose nanofibers (CNFs) as fillers for eco-friendly composite materials has increased significantly in recent years [1][2][3][4][5][6][7]. CNFs are derived from natural sources and the chemical structure composed of glycosidic linkages between glucose is easily decomposed into glucose monomers by natural sunlight, humidity, and bacteria. CNFs thus result in low environmental impact during production and disposal. This eco-friendly nature of CNFs rides on the technical need to replace synthetic fillers (e.g. glass fiber, carbon, or aramid) with natural organic ones in the development of polymer composites, especially in the use of thermoplastics.CNFs can be extracted by the cleavage of fibrils from plant sources through mechanical processes such as grinding, ball milling, ultrasonic treatment, and the aqueous counter collision (ACC) method [8][9][10][11][12][13][14][15]. The CNFs produced are micrometer-long fibrils having entangled cellulose chains that are tightly aggregated together by van der Waals forces and strong intra-and intermolecular hydrogen bonds [16]. Unlike cellulose nanocrystals (CNCs), which exhibit near-perfect crystallinity of over approx. 90%, the CNF contains both crystalline and amorphous domains along the length. The crystal domains in cellulose chain molecules that are highly ordered and closely packed promote high stiffness, strength, and thermal stability for the CNFs, while the amorphous or disordered domains contribute to the mechanical flexibility [17].Various experimental and theoretical studies have revealed the excellent mechanical properties of CNFs. A tensile strength of ~3 GPa has been reported for them [18], which is similar to that of aramid fibers, and their Young's modulus was recorded as 20-30 GPa [19][20][21][22]. Their thermal expansion coefficient is as low as 0.1 ppm K −1 , similar to that of quartz glasses [23]. In addition to these useful mechanical properties of CNFs, their low

A sustainable single-component “Silk nacre”

“…Besides, the strength and modulus of our Silk nacre exceeded many frequently used polymers (Fig. 2C) (32)(33)(34)(35)(36)(37)(38)(39)(40), suggesting its considerable potential as an alternative to synthetic polymers in terms of mechanical performance.…”

“…(A and B)The Silk nacre shows both better strength and toughness than that of homogeneous silk plate according to the data calculated from stress-strain curves. (C) Comparison of modulus and strength among silk plate, the Silk nacre, and various frequently used polymers [from(32)(33)(34)(35)(36)(37)(38)(39)(40)]. PBS, poly(butylene succinate); PP, polypropylene; PA-6, polyamide 6; PET, polyethylene terephthalate; PMMA, polymethyl methacrylate; PC, polycarbonate; ABS, acrylonitrile butadiene styrene; PVC, polyvinyl chloride; PS, polystyrene; the red star refers to the Silk nacre.…”

Interphase parameter prediction in nanocellulose composites using young modulus modeling

“…20,21 Because of this characteristic, nanocellulose is poorly dispersed in hydrophobic polymer matrixes, leading to poor composite performance as a result of a low nanocellulose/matrix interaction. 20,22,23 Therefore, several approaches were used to achieve a homogeneous distribution of nanocellulose in polymer matrices 20,21,24 including: solution mixing, [25][26][27] reactive compatibilization, 21,24,28,29 ringopening polymerization, [30][31][32] and surface modification of CNCs. [33][34][35] Mechanical properties of nanocomposites are known to be affected by a wide variety of factors, including nanofiller concentration, aspect ratio, stiffness, dispersion, and orientation, and interphase characteristics like thickness, modulus, and strength.…”

“…20,21 Because of this characteristic, nanocellulose is poorly dispersed in hydrophobic polymer matrixes, leading to poor composite performance as a result of a low nanocellulose/matrix interaction. 20,22,23 Therefore, several approaches were used to achieve a homogeneous distribution of nanocellulose in polymer matrices 20,21,24 including: solution mixing, 25–27 reactive compatibilization, 21,24,28,29 ring-opening polymerization, 30–32 and surface modification of CNCs. 33–35…”

Effect of Cellulose Microfiber Silylation Procedures on the Properties and Antibacterial Activity of Polydimethylsiloxane

“…Consequently, cellulose surface modification is of interest in order to improve compatibility with a variety of polymer matrices [14]. Many chemical and physical treatments methods have been proposed for cellulose surface modification, including corona or plasma discharges [15], vacuum UV treatments [16], and chemical methods, which involve pretreatment of fiber surfaces by coupling agents (such assilanes and isocyanates) [17,18], grafting processes [19,20], and alkali treatments [21], among other methods.…”