Preparation and Characterization of Organoclay-Filled, Vinyl Ester-Modified Unsaturated Polyester Nanocomposites

Abstract

Organophilic montmorillonite clay — unsaturated polyester (UP) and vinyl ester oligomer (VEO) — unsaturated polyester nanocomposites were prepared and the formation of nanocomposites was evaluated by X-ray diffraction (XRD), dynamic mechanical analysis (DMA) and scanning electron microscopy (SEM). The VEO was prepared by reacting commercially available epoxy resin LY556 and acrylic acid and was used as a toughening agent for unsaturated polyester resin. Organoclay-filled hybrid VEO—UP matrices, developed in the form of castings, were characterized for their thermal and mechanical properties. Dynamic mechanical measurements indicated the presence of higher crosslink density for the clay-filled systems than unfilled systems. X-ray diffraction analysis infers the intercalation of the polymer molecules between the clay layers which in turn restricts the mobility of polymer in the vicinity of clay layers. A shift in Tg towards lower temperature was observed for nanocomposites. Significant improvement in the mechanical properties was also observed in the case of nanocomposites when compared with neat resin matrix.

Dispersion and improvement of organoclays in nanocomposites based on poly(propylene oxide)

“…Nanocomposites are a relatively new class of materials, which are defined by the particle size of the dispersed phase having dimension less than 100 nm. 1 Nanocomposites have attracted great interest as promising advanced materials due to their superior properties compared to conventional polymers 2,3 such as density, high resistance to surface treatment, high modulus of elasticity, non-flammability and thermomechanical/ optoelectronic/magnetic properties. [4][5][6] Indeed, the use of a polymer matrix by adding a well-defined percentage of clay as reinforcement leads to the improvement of the physicochemical properties of the resulting nanocomposite and increases the biodegradability of the polymer.…”

Spectral, surface and thermal properties of poly(vinylpyrrolidone)/organo-modified-TiO2/organo-modified-layered silicate ternary nanocomposites containing l-leucine amino acid fabricated by sonication process

“…Young's modulus, heat deflection temperature, permeability, yield stress and flammability. 11,12 Polymer/clay NCs have been widely considered since the Toyota research group effectively prepared nylon 6/montmorillonite (MMT) NCs in 1993. In many cases, the addition of a small amount ($5 wt%) of nanoclay to the polymer matrix was adequate to cause notable developments in various properties of them.…”

“…The layer thickness of MMT is around 1 nm, and the lateral dimensions range from 30 nm to several micrometers. 7,12 Sodium MMT is the most extensively utilized type of silicate clay in the polymer NCs. It is a reinforcing material, naturally abundant, inexpensive, nontoxic, thermally and chemically stable.…”

“…X-ray diffraction (XRD), transmission electron microscopy (TEM) and field emission scanning electron microscopy (FE-SEM) techniques could be utilized to determine the degree of exfoliation, in addition to the shape and size of NPs in the polymer matrix. 12,20 The most important factor to obtain the best physical, mechanical and chemical properties is to exfoliate the individual MMT platelets into the polymer matrix. 21 Depending on the composition and microstructure, the effects of diverse NPs on the properties of macromolecules are different.…”

Effect of clay on the corrosion inhibition and dynamic mechanical properties of epoxy ester–polyurea–polysiloxane hybrid coatings

“…The mechanical and barrier properties of epoxy ester can also be improved by adding montmorillonite cloisite 15A clay, which has an aspect ratio of about 200 [31]. The incorporation of clay in epoxy esters has been shown to increase the fire retardancy, surface hardness, and mechanical properties [32–34]. Moisture diffusivity has been reported to decrease by 50% and gas permeability by 23% with the addition of a small amount of clay in the polymer clay nanocomposites [35–38].…”