Abstract
Three kinds of orgno-bentonite (MMT) were prepared from sodium montmorillonite and dimethylstearyl-benzylammonium chloride (DMSB). DMSB31-MMT was prepared from equimolar amount of sodium montmorillonite and DMSB. The gallery expansion of the MMT was 19.2Å. DMSB31-MMT-Me0H was prepared with expansion of DMSB31-MMT by methanol. The gallery expansion of the MMT was 36.0Å. DMSB52-MMT was prepared from sodium montmorillonite and excess amount of DMSB. The gallery expansion of the MMT was 38.4Å. Phenolic rein-layered silicate nanocomposites were prepared from conventional phenol novolac, hexamethylenetetramine and these MMTs by hot-roll kneading. Phenolic resin was intercalateed between layers of these MMTs, especially DMSB31-MMT-Me0H and DMSB52-MMT were finely dispersed in phenolic matrix. The gallery expansion of these MMTs was 38-45Å. Flexural strength, flexural strain and tensile strength of phenolic/DMSB31-MMT nanocomposites were inferior to those of others. The main reason was considered that a part of MMT was aggregated in phenolic matrix and the dimension of the aggregation became a few micron meter. Phenolic/DMSB52-MMT nanocomposites had the best mechanical properties, which may be associated to the following reasons : DMSB52-MMT was finely dispersed in phenolic matrix and excess amount of DMSB between layered MMTs acted as plasticizer.
