The role of organic modification of layered nanosilicates on mechanical and surface properties of organic–inorganic coatings

Abstract

The effect of alcohol-and amino-functional compatibilizers in nanocomposites of organic-inorganic (O-I) matrices with layered nanofillers (LN) was studied. The alcohol-functional compatibilizers are shown to have a marked influence on morphology, surface-and mechanical properties of the coatings prepared, in spite of the very small amount of both filler and compatibilizer (together 0.5 wt%). The studied O-I matrices were polyepoxy-functional polysiloxanes cured with organic diamines. Two commercial clays were used as LN in the concentration of 0.5 wt%: natural montmorillonite (Cloisite Na, abbreviated MNa) and Bentonite for water systems (BW). These clays were compatibilized by three hydroxylcontaining substances: Polyethylene glycol 4000, TWEEN 80, and tris(hydroxymethyl)aminomethane (TRIS). All compatibilizers improve the dispersion of the clay fillers, while TRIS always supports full exfoliation. They also cause an increase in the microroughness of the coatings and strongly modify their large-scale surface patterns. Mechanical properties are also strongly affected by the compatibilizers: toughness is increased, sometimes markedly, as well as stress at break. Tensile and shear moduli are reduced by the compatibilizers, while the glass transition temperature is specifically shifted to higher or lower values, sometimes markedly.

Morphology, crystallization, thermal, and mechanical properties of poly(vinylidene fluoride) films filled with different concentrations of polyhedral oligomeric silsesquioxane

“…The further additions of FP‐POSS, which leading to multinucleation of the PVDF matrix and generating looser net‐like particles, made the polymer matrix more easy to form plastic flow and more efficient on energy dissipation. Meanwhile, compared with the results of the engineering stress–strain response above, the properties of the composites at the weight of 3 wt% and 5 wt% FP‐POSS were excellent, because of increment both in stiffness and toughness, whereas most filler could only increase either in stiffness or in toughness [50, 51]. It seems that FP‐POSS, combining in a good ratio with PVDF matrix, has acted as fillers of reinforced stiffness and toughness at the same time.…”

Effect of nano SiO2 particles on the morphology and mechanical properties of POSS nanocomposite dental resins

“…For the compressive strength (shown as Fig. 5), when the weight The content of nanofiller and dispersion of nanoparticles were the key factors for improving the mechanical properties of the matrix (Qi et al 2006;Schiraldi and Iyer 2007;Š pírková, Duchek et al 2011;Liu, Sun et al 2013). When the addition of fillers was low, the nano SiO 2 probably made the particles bigger and more condensed.…”

Organic–inorganic hybrid sol–gel materials doped with a fluorescent triarylimidazole derivative

“…[22][23][24][25][26][27][28][29] The organic moieties of these materials include the commercial polyetheramines, particularly Jeffamines®, which have been frequently reported in the preparation of OIH materials. 23,25,26,[30][31][32][33][34][35][36] The use of Jeffamines® precursors to prepare sol-gel materials can result in urea silicates or aminoalcohol silicates matrices, depending on the silane used and type of bond established i.e., urea or aminoalcohol, respectively. These materials can be doped with chromo-uorogenic chemosensors and become sensitive membranes that can be applied to OFS.…”