Polymer-clay hybrid

Layered nanoparticles, like the aggregates of silicates talc and mica, form close proximity sheets of polymer—clay hybrids due to the immiscibility of clay in polymer. The degree of dispersion in these composites is normally referred to as the following ... 

Okada, A. and UsuM, A. 1995. The chemistry of polymer-clay hybrids. 

G. Defontaine, A. Barichard, S. Letaief, C. Feng, T. Matsuura, C. Detellier, Nanoporous polymer - clay hybrid membranes for gas separation. Journal of Colloid and Interface Science 343 (2010) 622-627. 

The are two basic ways of making polymer/clay hybrids. Direct polymerization in the presence of clay platelets has been used successfully for polyamides and for epoxy and other resins. But, at a less exotic and more flexible level, compounding offers an economic way of modifying polypropylene - in theory - and there has been some active development of processes to produce polypropylene/clay hybrids by melt mixing. 

Polymer/clay hybrid nanocomposites, used in automotive, packaging, and aerospace applications (Dagani 1999), may be prepared. 

Okada A, Usuki A (1995) The chemistry of polymer-clay hybrids. Mat Sci Engg C3 109-115 Reis JML, Mota EP (2014) Mechanical behaviour of piassava fiber reinforced castor oil polymer mortars. Comp Strut 111 468-472... 

Kawasumi M (2004) The Discovery of Polymer-Clay Hybrids, J Polym Sci, Polym Chem Ed 42 819-824. 

Nanometer-scale composites prepared from layered inorganic materials, especially clay, and polymers have also attracted much attention because of their unique optical, thermal, mechanical, gas barrier, and electrical properties. There are many reports describing polymer-clay nanocomposites. " The clay can be, for example, a sihca or silicate. In such a hybrid composite, weak dipolar and van der Waals forces provide the driving force for interactions between the layers, and they result in galleries being formed. There are three types of clay-polymer composites conventional, intercalated, and exfohated. Three mediods are widely used for the preparation of polymer-clay hybrid nanocomposites intercalation by in situ polymerization, direct intercalation, and polymer melt intercalation. Each of these methods has its advantages and disadvantages. For example, the in situ polymerization works only in tiie... 

Okada, A., Kawasumi, M., Usuki, A, Kojima, Y., Kurauchi, T. and Kamigaito, 0.1990. Synthesis and properties of nylon-6/clay hybrids. In Schaefer DW, Mark ]E. eds. Polymer based molecular composites. Pittsburgh. MRS Symposium Proceedings 171 45-50. 

Usuki, A., Tukigase, A. and Kato, M. 2002. Preparation and properties of EPDM- clay hybrids. Polymer 43 2185-2189. 

A. Okada, M. Kawasumi, A. Usuki, Y. Kojima, T. Kurauchi and O. Kamigaito, Nylon 6-clay hybrid. In D.W. Schaefer and J.E. Mark (Eds.), Polymer-Based Molecular Composites,, Materials Research Society, Pittsburgh, 1990, Vol. 171, p. 45. 

Y. Kojima, A. Usuki, M. Kawasumi, A. Okada, T. Kurauchi, 0. Kamigaito, Synthesis of nylon 6-clay hybrid by montmorillonite intercalated with e-caprolactam, Journal of Polymer Science Part A Polymer Chemistry, vol. 31, pp. 983-986,1993. 

Polymer-clay nanocomposites (PCN) are a class of hybrid materials composed of organic polymer matrices and organophilic clay fillers, introduced in late 1980s by the researchers of Toyota (Kawasumi, 2004). They observed an increase in mechanical and thermal properties of nylons with the addition of a small amount of nano-sized clays. This new and emerging class of pol miers has found several applications in the food and non-food sectors, such as in constmction, automobiles, aerospace, military, electronics, food packaging and coatings, because of its superior mechanical strength, heat and flame resistance and improved barrier properties (Ray et al., 2006). 

Bourbigot, S., Devaux, E., and Flambard, X. 2001. Flammability of polyamide-6/clay hybrid nanocomposite textiles. Polym. Deg. Stab., 75(2) 397 102. 

Furthermore, CNT-clay hybrid filler can also be used to prepare polymer nanocomposites by solution based method. Hydrophilic... 

These clays have been hybridized with diverse structural types of components such as nanoparticles, clusters, complex compounds, polymers, molecules, and ions. Their potential apphcations are found in many fields as inorganic catalysts, adsorbents, ceramics, coatings, and even drug delivery carriers. Various preparation methods have been developed such as pillaring, intercalation, and delamination techniques. The representative examples include organic-clay hybrids," metal oxide-pillared clays, " and bioclay hybrids. ... 

Hasegawa, N. Okamoto, H. Kawasumi, M. Usuki, A. Preparation and mechanical properties of polystyrene-clay hybrids. J. Appl. Polym. Sci. 

In one example, the tensile strength of polyamide 6 was increased by 55% and the moduli by 90%, with the addition of only 4wt% of delaminated clay. The enhanced tensile property of PCN suggests that nanocomposite performance is related to the degree of clay delamination, which increases the interaction between the clay layers and the polymers. Several explanations, based on the interfacial properties and the mobility of the polymer chains, have been given for this reinforcement. Kojima et al. reported that the tensile modulus improvement for polyamide 6-clay hybrid originated from a constrained region, where the polymer chains have reduced mobility. The dispersion and delamination of the clay were the key factors for the reinforcement. The delaminated nanocomposite structure produces a substantial increase in modulus. 

Yano, K. Usuki, A. Karauchi, T. Kamigaito, O. Synthesis and properties of polyimide-clay hybrid. J. Polym. Sci. Polym. Chem. 1993,31, 2493-2498. 

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