Effects of interfacial modifier on rheological behavior of kaolin toughened polyamide 6 (PA6) were studied and compared with those of silane coupling agent KH550. The addition of the interfadal modifier to PA6/Kaolin (80/20) composites improves the melt viscosity and the melt elasticity (first normal stress difference). However

the use of KH550 reduces the melt viscosity and the melt elasticity. This difference is attributed to the stronger interaction betWeen PA6 and kaolin and better elastic resilience of the interfacial modifier than that of KH550. Furthermore

the contents of the interfacial modifier has an influhnence on rheological behavior of the PA6/kaolin composites. The interfacial modifier tends to "saturation" on the kaolin surface when its content is 2% by weight. Further increasing the interfacial modifier affects the rheological behavior of the composites little.