General approach to nanocomposite preparation

A novel approach to nanocomposite preparation utilizing a swelling agent, a monomer or polymer known to intercalate/exfoliate smectite clay, has allow ed the preparation of several new nanocomposites. Present in small amounts, the swelling agent serves to swell the clay layers, allowing the organic m atrix to be virtually any polymer. Twenty-four polymers are used in this st udy, varying in solubility parameter, molecular weight, and polarity. Many of these polymers do not yield a nanocomposite structure by simple melt mix ing of the clay and polymer. Although some polymers are capable of partial intercalation or exfoliation without the addition of a swelling agent, addi tion of 2 wt% of this additive results in either complete intercalation/exf oliation or an increased percentage of nanocomposite formation, in comparis on to the clay-polymer mix. The evidence of a nanocomposite structure is pr ovided by a shift in, or the absence of, clay reflections in X-ray powder d iffraction patterns.