Interfacial tension and morphology of polyamide6 (PA6) and polypropylene (P
P) blends containing polvpropylene grafted with maleic anhydride (PPMAH) as
reactive compatibilizer were studied by Neumann Triangle method, Scanning
Electron Microscopy and Transmission Electron Microscopy. It was observed t
hat there was a significant reduction of interfacial tension due to the in
situ formed copolymer at the interface acting as an emulsifier, and there w
as a limiting value of the interfacial tension under a saturation concentra
tion of compatibilizer (C-saturation) at which the interface was saturated
by the in situ formed copolymer. For the morphology, there was also a criti
cal concentration of the compatibilizer (C-critical). For decreasing the si
ze of the dispersed phase, there was no further decrease in the dispersed p
article size above C-critical. The areal density of the in situ formed copo
lymer (Sigma (critical)) was estimated, and it was concluded that to emulsi
fy the PA6/PP blend, 100% coverage of the interface by the in situ formed c
opolymer was not required; up to 63.7% coverage of the interface is suffici
ent. (C) 2001 Elsevier Science B.V. All rights reserved.