Modifying montmorillonite clay via silane grafting and interfacial polycondensation for melt compounding of nylon‐66 nanocomposite

Abstract

A trifunctional organo alkoxysilane (3-aminopropyl)triethoxysilane (c-APS) has been used as reagent for the chemical modification of montmorillonite clay. Silane grafting was taken place in dry and hydrolyzing conditions. Silane grafted and pristine clay took part in interfacial polycondensation process to deposit a layer of nylon-66 onto the clay lamellae and therefore, enhance their affinity with nylon-66 matrix. Evidence of presence of grafted silane molecules and deposition of nylon-66 on clay particles were provided by Fourier transform-infrared, thermogravimetric analysis (TGA), and X-ray diffraction (XRD). Such modified clays and pristine clays were melt compounded with nylon-66. The structures of the resulting nylon composites were characterized using XRD and transmission electron microscopy and the results showed presence of both intercalation and exfoliation. TGA thermograms of nanocomposites indicated improved thermal stability upon the incorporation of silane grafted montmorillonite. Furthermore, differential scanning calorimetry scans showed that silane modified clays promoted crystallization in nanocomposites. Increase of storage modulus and depression of tan d peak in nanocomposites in dynamical mechanical thermal analysis were observed. The rheological properties of nylon-66 and nanocomposites were also evaluated and differences in values of complex viscosity of samples were noticed.

Estudo da estabilidade térmica e propriedades mecânicas de nanocompósitos de poliamida 6,6 com nanofibras de celulose

“…As amostras pré-misturadas tiveram uma diminuição na deformação plástica e deformação máxima de 4,4 ± 0,2 % (amostra PA-P0) para 3,3 ± 0,3 % (amostra PA-P1) e 3,8 ± 0,4 % (amostra PA-P2), correspondendo a uma redução de 10%, em média. Esse decréscimo na ductibilidade com a adição de fibras em polímeros é uma tendência comumente observada para compósitos termoplásticos [9,20,24,25]. …”

Synthesis and Characterization of Chitosan/Phosphotungstic Acid-Montmorillonite Modified by Silane for DMFC Membrane

“…Montmorillonite was modified by silane according to the procedure describe in the literature [19]. Montmorillonite and 3-glycidyloxypropyl)trimethoxy silane (5, 10 and 15%) were dissolved in dimethyl formamide and then stirred at room temperature for 6 h. Subsequently, the homogenous solution put into oven at 60°C for 24 h. The reaction be continued at 100°C for 1 h and then at 120°C for 2 h. After that, 1 M hydrochloride acid was added to the dry products at 80°C for 24 h. The products were denoted as MMTsilane 5%, MMT-silane 10% and MMT-silane 15%.…”

Preparation and Characterization of Some Hyperbranched Polyesteramides/Montmorillonite Nanocomposites

“…Generally, polymer/clay nanocomposites have been widely used in many fields, such as automobile and tire industries, construction fields, food packaging, electrical fields, antimicrobial agents, and other potential applications [13][14][15][16][17]. Several polymers are involved in producing such nanocomposites as vinyl polymers [18,19], condensation polymers [20,21], polyolefins [22,23], and others [24,25]. Hyperbranched polymers have been lately used in such nanocomposites due to their brilliant physical and chemical properties to obtain nanocomposites with excellent properties that can be invested in different applications [26,27].…”