Clay properties films

Polyimide-clay nanocomposites constitute another example of the synthesis of nanocomposite from polymer solution [70-76]. Polyimide-clay nanocomposite films were produced via polymerization of 4,4 -diaminodiphenyl ether and pyromellitic dianhydride in dimethylacetamide (DMAC) solvent, followed by mixing of the poly(amic acid) solution with organoclay dispersed in DMAC. Synthetic mica and MMT produced primarily exfoliated nanocomposites, while saponite and hectorite led to only monolayer intercalation in the clay galleries [71]. Dramatic improvements in barrier properties, thermal stability, and modulus were observed for these nanocomposites. Polyimide-clay nanocomposites containing only a small fraction of clay exhibited a several-fold reduction in the... 

Yano, K., Usuki, A., and Okada, A. 1997. Synthesis and properties of polyimide-clay hybrid films. Journal of Polymer Science, Part A Polymer Chemistry 35 2289-2294. 

Russo P, Cammarano S, Bilotti E, Peijs T, Cerruti P, Aciemo D (2014) Physical properties of poly lactic acid/clay nanocomposite films effect of filler content and annealing treatment. J Appl Polym Sci 131. doi 10.1002/app.39798... 

Masoodi R, El-Hajjar RF, Pillai KM, Sabo R (2012) Mechanical characterization of cellulose nanofibca- and bio-based epoxy composite. Maha- Des 36 570-576 Melo Cd, Garcia PS, Grossmann MVE, YamashitaF, Dali Antonia LH, Mali S (2011) Properties of extraded xanthan-starch-clay nanocomposite films. Braz Arch Biol Technol 54 1223-1333 Mogri Z, Paul DR (2001) Water-vapor permeation in semicrystalhne and molten poly(octadecyl acrylate). J Polym Sci, Part B Polym Phys 39 979-984 Mohanty AK, Misra M, Drzal LT (2002) Sustainable bio-composites from renewable resources opportunities and challenges in the green mahaials worid. J Polym Environ 10 19-26... 

Polyimides (PI) are widely used in microelectronics and photonics because of their outstanding electrical properties, heat resistance, and chemical stability [10-12], Pl/clay nanocomposites have been reported to reduce the coefficient of thermal expansion, amount of moisture absorption, and dielectric constant for improved performance in these application areas already mentioned [13-22], For example, Yano et al. [13] prepared a PI (pyromellitic anhydride-4,4 -oxydianiline)/clay composite film [(PMDA-ODA)/clay] by solution-mixing of polyamic acid (PAA) and a dimethylacetamide (DMA) dispersion of clay. They used dodecylamine as the clay modifier, and the film showed reduced thermal... 

This chapter describes recent progress in studies aimed at understanding effects of various chemical modification methods on the state of dispersion of clay particles in a high-temperature PI matrix and on the physical properties of polymer/clay nanocomposite films. Three different modification methods and their effects on the Pl/clay nanocomposite... 

A. M. Slavutsky, M. A. Bertuzzi, and M. Armada, Water barrier properties of starch-clay nanocomposite films. Braz. J. Food Technol. 15,208-218 (2012). 

Sothornvit, R., Hong, S., An, D. J.,and Rhim, J. Effect of clay content on the physical and antimicrobial properties of whey protein isolate/oigano-clay composite films. LWT-Food Sci. Technol, 43, 279-284 (2010). 

In this work, the starch/PVOH/silicate clay blend films were prepared by a solution casting method. Four different types of layered silicate clays were used to investigate the compatibility of multiphased system. Special attention is driven to study the effect of the clay content on the film properties based on barrier and mechanical modeling predictions of nanocomposite films. 

Tang, X. Z., Alavi, S., and Herald, T. J. Barrier and Mechanical Properties of Starch-Clay Nanocomposite Films. Cereal Chemistry, 85,433-439 (2008 a). 

Tang X, Alavi S, Herald TJ. Barrier and mechanical properties of starch-clay nanocomposite films. Cereal Chem 2008 85(3) 433-9. 

Das, K., Ray, D., Baneijee, I., Bandyopadhyay, N.R., Sengupta, S., Mohanty, A.K., Misra, M., 2010. Crystalline morphology of PLA/clay nanocomposite films and its correlation with other properties. Journal of Applied Polymer Science 118, 143—151. 

Ghasemi H, Carreau PJ, Kamal MR, Tabatabaei SH. Properties of PET/clay nanocomposite films. Polym Eng Sci 2012 52 420-430. 

Hong SI, Rhim JW. Preparation and properties of melt-intercalated linear low density polyethylene/clay nanocomposite films prepared by blow extrusion. Lwt-Food Sci Technol 2012 48 43-51. 

Shafiee M, Ramazani SAA, Danaei M. Investigation of the gas barrier properties of PP/clay nanocomposite films with EVA as a compatibiliser prepared by the melt intercalation method. Polym-Plast Technol Eng 2010 49 991-995. 

Fujimori A, Ninomiya N and MasukoT (2008), Structure and mechanical properties in drawn poly (L-lactide/clay) hybrid films , Polym Adv Technol, 19,1735-1744. 

Triantafyllidis KS, LeBaron PC et al (2006) Epoxy-clay fabric film composites with unprecedented oxygen-barrier properties. Chem Mater 18 4393... 

Polar organic solvents, such as dimethyl formamide, dimethyl acetamide, or 1-methyl-2-pyrolidone are used in clay dispersion used in manufacture of clay thin film usable for solar eells or display devices, due to the excellent gas barrier property and heat resistanee. ... 

Uses Defoamer for paper coatings, adhesives, and high gloss latex paints Features Promotes defect-free surf, films compat. with most paper coatings containing latex, polyvinyl alcohol, starch, and clay Properties Water disp. 100% act. 

As is known, plastieizers pl an indispensable role because the plasticizers can form hydrogen bonds with the stareh, replacing the strong interactions between the hydroxyl groups of the starch moleeules, and thus making stareh thermoplastic (Hulleman et al, 1998 Ma Yu, 2004 Ma et al, 2004). It was hypothesized that plasticizers might also participate in the interaetions between stareh and clay and therefore eould greatly alfeet the formation of nanostructure and further influenee the mechanieal and water vapor barrier properties of starch-clay nanocomposite films. 

Figure 19 shows the WVP of stareh-clay nanocomposite films imder different screw configurations. As a result of better delamination and dispersion of clay platelets, high shear intensity screw configuration led to the lowest WVP (0.48 g mm/kPa h m ) of the films, whereas low shear intensity led to the highest WVP (0.85 g mm/kPa h m ). Similar results can be found for the tensile properties (Table 9). With the increase of the shear intensity, tensile strength increased and elongation decreased due to the better dispersion of clay platelets in the starch matrix. 

Table 9. Tensile properties of starch-clay nanocomposite films based on different shear intensity screw configurations (Tang et al., 2008c)...

Yano et al prepared polyimide-clay hybrid films with four different sizes of clay minerals in order to investigate the effect of the aspect ratio on the properties of the hybrids. Hectorite, saponite, montmorillonite and synthetic mica were used as clay minerals. They found that, at constant clay content (2 wt.%), the relative permeability coefficient decreases on increasing the length of the clay (Fig. 11.2). 

Andrade M L Q, Manrich S, Pessan L A, Transport properties and solvent induced-crystallization in PET and PET-clay nanocomposite films , J. Metastable Nanocryst. Mater., 2004 22 51-6. 

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