Sequential and Simultaneous Melt Intercalation of Poly(ethylene oxide) and Poly(methyl methacrylate) into Layered Silicates

• Published in: Macromolecules Vol. 38; no. 5; pp. 1744 - 1751
• Main Authors: Shen, Zhiqi, Cheng, Yi-Bing, Simon, George P
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 08.03.2005
• Subjects: Applied sciences; Composites; Exact sciences and technology; Forms of application and semi-finished materials; Polymer industry, paints, wood; Technology of polymers; Mixing; Organic clay; Polymer blends; Montmorillonite; Insertion; Methyl methacrylate polymer; Experimental study; Ethylene oxide polymer; Sequential method; Supramolecular structure; Bentonite; Nanocomposite; Manufacturing; Growth from melt; Comparative study
• ISSN: 0024-9297; 1520-5835
• DOI: 10.1021/ma040099k

Both poly(ethylene oxide) (PEO) and poly(methyl methacrylate) (PMMA) were melt intercalated in a sequential or simultaneous (blend) manner into two layered silicates, a sodium montmorillonite (MMT) and an organically modified bentonite (B34). The B34 nanoclay, which was already pre-intercalated to the point of saturation by PEO, was found able to take up additional PMMA. The converse was also found to be true where, despite the silicate galleries being saturated by PMMA, additional PEO was able to be incorporated. This implies that the packing density of the mixed PEO and PMMA phase in the gallery of B34 is greater than that of either polymer alone in the gallery. The intercalation of a miscible PEO/PMMA blend into B34 results in a greater increase in the spacing between layers than by either for a PEO-B34 hybrid or for a saturated PMMA−B34 hybrid. However, the intercalation of a PEO/PMMA blend into MMT results in the same gallery size increase as for the PEO−MMT hybrid. The organically modified bentonite is thus able to host a higher concentration of macromolecular chains from a miscible blend than from either polymer alone. The presence of PEO, which has a lower intercalation temperature than PMMA, thus encourages reptation of the PMMA into the silicate galleries at temperatures below that it could move in alone.