Structure and thermal/mechanical properties of poly (ϵ-caprolactone)-clay blend

✍ Scribed by Guillermo Jimenez; Nobuo Ogata; Hidekazu Kawai; Takashi Ogihara

• Publisher: John Wiley and Sons
• Year: 1997
• Tongue: English
• Weight: 310 KB
• Volume: 64
• Category: Article
• ISSN: 0021-8995
• DOI: 10.1002/(sici)1097-4628(19970613)64:11<2211::aid-app17>3.0.co;2-6

✦ Synopsis

Montmorillonite was organically modified with distearyldimethylammonium chloride. This organically modified clay (OMON) and poly( e-caprolactone) (PCL) were solvent-cast blended with chloroform, and the structure and properties of the resulting PCL-clay blends were investigated. From isothermal crystallization experiments, it was found that a small amount of OMON in the blend accelerated the crystallization of PCL, whereas a large amount of the organophilic clay delayed it. From smalland wide-angle X-ray scattering measurements, it was found that the silicate layers forming the clay could not be dispersed individually in the PCL blends. In other words, the clay seemed to exist as the tactoids consisting of some silicate layers. These tactoids formed a remarkable geometric structure; that is, their surface planes lay almost parallel to the blend film surface. Furthermore, the tactoids were stacked with insertion of PCL lamellae in the film-thickness direction. Preferred orientation of the PCL crystallites was induced by the presence of the clay. During the drawing process of the blends, fibrillation took place with formation of planelike voids developed on the plane parallel to the film surface. From dynamic viscoelastic measurements, it was shown that intercalation of PCL chains into the layered silicates did not take place in the blends prepared by the solvent-cast method used in this work.