Organically modified clay

Chapter 6 Organically Modified Clays for Pollutant Uptake and... 

Organically modified clays are mixtures of anthracite and bentonite clay or bulk clay. The surface of the clay is usually activated after treating with a quaternary amine. These clays are employed only in the purification of gas streams. 

The incorporation of unmodified and organically modified montmorillonite nanoclays (namely 15A and 30B) in chlorinated polyethylene (CPE) by the solution intercalation method and their influence on mechanical properties of the nanocomposites have been studied by Kar et al. [137]. The o-MMT-embedded nanocomposites show enhanced tensile strength and Young s modulus in comparison to the nanocomposites containing the unmodified nanoclay. They have shown from and XRD analyses that organically modified clay shows better dispersion in the CPE matrix. This has been further substantiated from FTIR analysis, which proves an interaction between the CPE matrix and the clay intercalates. 

Fig. 38 WAXD patterns of stearic acid, clay, and swollen clay. The swollen clay was prepared by mixing stearic acid and organically modified clay (Nanofil-15) at the ratio of 1 1...

G. Chigwada and C.A. Wilkie, Synergy between conventional phosphorus fire retardants and organically-modified clays can lead to fire retardancy of styrenics, Polym. Degrad. Stabil., 2003, 80 551-557. 

The results are reported of an in depth study of the structure, thermal properties, dynamic mechanical properties, flammability and smoke properties of melt blended PVC-sodium montmorillonite nanocomposites. Investigative properties employed included X-ray diffraction, TEM, TGA, DMA and cone calorimetry. The effects of clay loading, DOP concentration, annealing, blending time and molec.wt. on the formation of the composites are discussed and fire properties of PVC-organically modified clay and PVC-sodium clay nanocomposites are presented and discussed. 15 refs. USA... 

The intercalation of polymer or prepolymer from the solution is described via minimum free energy principle. The driving force of polymer intercalation is the entropy from the solvent desorption. Several researchers investigated the thermodynamics properties of PCN with homo polymeric systems in a confined geometry. However, Lim et al. investigated ternary systems, and explained that the intercalation distance of poly-(methyl methacrylate) (PMMA)/organic-modified clay (OMMT) nanocomposite is larger than that for the... 

Polymer clay nanocomposites have, for some time now, been the subject of extensive research into improving the properties of various matrices and clay types. It has been shown repeatedly that with the addition of organically modified clay to a polymer matrix, either in-situ (1) or by melt compounding (2), exfoliation of the clay platelets leads to vast improvements in fire retardation (2), gas barrier (4) and mechanical properties (5, 6) of nanocomposite materials, without significant increases in density or brittleness (7). There have been some studies on the effect of clay modification and melt processing conditions on the exfoliation in these nanocomposites as well as various studies focusing on their crystallisation behaviour (7-10). Polyamide-6 (PA-6)/montmorillonite (MMT) nanocomposites are the most widely studied polymer/clay system, however a systematic study relating the structure of the clay modification cation to the properties of the composite has yet to be reported. 

PLA nanocomposite samples used in this study were prepared with PLA (Teramac , Unitika) and organically modified clay (S-BEN W , Hojun). The samples were put into a Labo-plastomill consisting of a 30C150 kneader and an RlOO mixer (Toyo Seiki Seisaku-sho, Ltd., Tokyo) to melt-blend at 190 °C and 50 rpm for about 10 minutes. Pellets thus obtained were pressed into 0.2 mm thick sheet sandwiched between two thick Teflon films by a hot press at 190 °C. 

Katti, K. S., Sikdar, D., Katti, D. R., Ghosh, P. Verma. D. (2006). Molecular interactions in intercalated organically modified clay andclay-polycaprolactam nanocomposites Experiments and modeling. Polymer, Vol. 47, No. 1, pp. 403-414 Kister, G., Cassanas, G. Vert, M. (1998). Structure and morphology of solid lactide-glycolide copolymers from n.m.r., infra-red and Raman spectroscopy. Polymer, Vol. 39, No. 15, pp. 3335-3340... 

FIGURE 12.8 Mean free-volume cavity diameter, determined from o-Ps lifetime, as a function of temperature for organically modified clay (T ), polyamide 6 ( ), and 65 wt%/35 wt% polyamide 6/organically modified clay nanocomposite (o). The dashed line represents the mean of a weight average of cavity sizes in a physical mixture of polymer and clay with no changes in the free-volume sizes in either polymer or clay. (Adapted from Winberg et al. [2005 a].)... 

Ho, D. L., Briber, R. M., and Glinka, C. J., Characterization of organically modified clays using scattering and microscopy techniques, Chem. Mater., 13, 1923-1931 (2001). 

Achillas et al. [55] have prepared, by the melt mixing method, and characterized PHB/organically modified clay nanocomposites. 

Organic modified clay Polymer chains or monomers... 

An epoxidized triglyceride oil was subjected to intercalation into an organically-modified clay, followed by acid-catalyzed curing of the epoxy-containing triglyceride, leading to the production of a new class of biodegradable-nanocomposites from inexpensive renewable resources. 

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