In-situ Synthesis of Polymer Nanocomposites

In intercalation of polymer from solution mode of nanocomposite synthesis, the organically modified silicate is dispersed in a solvent in which the polymer is also soluble. The polymer then adsorbs onto the delaminated sheets followed by the evaporation of the solvent. When the solvent is evaporated, the sheets reassemble, which also trap the polymer chains in between. Thus, an ordered multilayer structure is usually formed using this approach. The polymer chains loose entropy in the process of intercalation, which is compensated by the increase in the entropy of the solvent molecules due to their desorption from the filler interlayers. The technique is mostly used for the intercalation of the water-soluble polymers Uke poly(vinyl alcohol), poly(ethylene oxide), poly(acrylic acid), poly(vinlypyrroUdone), etc. [20-24], Later on, the use of this technique was also undertaken in organic solvents for polymers nonsoluble in water [25, 26], 

In-situ intercalation method was reported by Toyota researchers for the synthesis of polyamide nanocomposites that led to the exponential growth in the nanocomposites research. For generation of polymer nanocomposites by this method, the layered silicate mineral is swollen in monomer. After swelling, the polymerization of the monomer is initiated. As monomer is present in and out of the filler interlayers, therefore, the generated stmcture is exfoUated or significantly intercalated. As the rate or mechanism of polymerization in and out of the filler interlayers 

5 Bailey, S.W. (1984) Reviews in Mineralogy, Virginia Polytechnic Institute and State University, Blacksburg, VA, USA. 

6 Brindley, G.W. and Brown, G. (1980). Crystal Structures of Clay Minerals and Their X-Ray Identification (eds G.W. Brindley and G. Brown), Mineralogical Society, London, UK. 

14 Mittal, V. (2010). Advances in Polymer Nanocomposites Technology (ed. V. Mittal), Nova Science Publishers, New York. 

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Living or controlled polymerization techniques have also been frequently used for the in-situ synthesis of polymer nanocomposites. Figure 1.20 shows the example of styrene polymerization in the presence of modified filler. The filler modification consisted of ammonium cation bearing a notroxide moiety [44]. Styrene was polymerized in bulk at 125 °C for 8h. No diffraction peaks were observed in the XRD confirming extensive exfoliation of the filler. TEM micrographs also confirmed the uniform distribution of filler in the matrix. Generation... 

In-situ Synthesis of Polymer Nanocomposites, First Edition. Edited by Vikas Mittal. 

Maneshi A, Soares J, Simon L (2011) Polyolefin-clay nanocomposites by in-situ polymerization. In Mittal V (ed) In-situ synthesis of polymer nanocomposites. Wiley-VCH, Weinheim, pp 53-88... 

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