Water Sorption in Polyamide 6/Poly(Amino-ether) Blends. II. Mechanical Behavior

Abstract

Polyamide 6 (PA)/poly(amino-ether of bisphenol A) (Blox) blends were placed in water for different times in an attempt to both find out whether the positive effects of Blox on the mechanical properties of PA are maintained in wet conditions, and to study the effects of solvent sorption on the mechanical properties of polymer blends.

After one week's sorption, the positive effects of the presence of Blox on the mechanical properties of PA were much larger than the composition would indicate, as 20% Blox led to a 100% increase in the modulus of elasticity with respect to that of the wet PA. After sorption for six weeks, the positive effects had decreased, attributed to a decrease in the interactions between PA and Blox, which was a consequence of the high miscibilized water content. The sorption/desorption process appeared to be only partially reversible as significant water contents remained in the blends even after very long desorption times and cracking was observed in blends very rich in Blox.

Keywords:

• Polyamide 6
• Poly(amino-ether)
• Water sorption
• Mechanical properties

Acknowledgments

The financial support of the University of the Basque Country (Project no. 9/UPV-13540/2001) is gratefully acknowledged. The authors also acknowledge Dr. Ha Q. Pham and Dr. Asjad Shafi, from Dow Chemical Company for supplying the Blox sample.