The nanocomposites based on biodegradable polycaprolactone (PCL) and organically modified layered silicates (organoclay) have been prepared by melt mixing. Their structure and properties have been characterized by wide angle X-ray diffraction technique (WAXD), thermal analysis and rheological measurements. The exfoliation of organoclay could be achieved via melt mixing process in the internal mixer which also showed dependence on the type of organic modifier, organoclay contents and the processing temperature. The addition of organoclay into PCL increases the crystallization temperature of PCL, however, high content of organoclay could show an inverse effect. The PCL/organoclay nanocomposites showed significant enhancement in their mechanical properties and thermal stability because of the exfoliation of organoclay. The nanocomposites showed much higher complex viscosity than that of the neat PCL and significant shear-thinning behavior in the low frequency range. The shear storage modulus, G, and loss modulus, G, of the nanocomposites also exhibited less frequency dependence than the pure PCL in the low frequency range which are caused by the strong interaction between the organoclay layers and PCL molecules and the good dispersion of exfoliated organoclay platelets in the PCL
Nanocomposites by melt intercalation based on polycaprolactone and organoclay
Iannace S;
2003
Abstract
The nanocomposites based on biodegradable polycaprolactone (PCL) and organically modified layered silicates (organoclay) have been prepared by melt mixing. Their structure and properties have been characterized by wide angle X-ray diffraction technique (WAXD), thermal analysis and rheological measurements. The exfoliation of organoclay could be achieved via melt mixing process in the internal mixer which also showed dependence on the type of organic modifier, organoclay contents and the processing temperature. The addition of organoclay into PCL increases the crystallization temperature of PCL, however, high content of organoclay could show an inverse effect. The PCL/organoclay nanocomposites showed significant enhancement in their mechanical properties and thermal stability because of the exfoliation of organoclay. The nanocomposites showed much higher complex viscosity than that of the neat PCL and significant shear-thinning behavior in the low frequency range. The shear storage modulus, G, and loss modulus, G, of the nanocomposites also exhibited less frequency dependence than the pure PCL in the low frequency range which are caused by the strong interaction between the organoclay layers and PCL molecules and the good dispersion of exfoliated organoclay platelets in the PCLI documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
