Ethylene-Propylene Elastomer Grafted Maleic Anhydride Toughened Polyamide-6 Morphology and Properties

Abstract

The effects of addition of elastomers [with and without grafted maleic anhydride (MA)] on the morphology and mechanical properties of polyamide 6 (PA6) blends were studied. The Molau test was adopted to confirm the formation of a graft copolymer between PA6 and ethylene-propylene elastomer (EPM); rheologial properties also indicated the graft reaction. Scanning electron microscopy (SEM) and differential scanning calorimetry (DSC) were employed to obtain some detailed quantitative analyses of the morphology of the elastomer particles and the melting and crystallization behavior for these blends containing 80 wt% PA6 and 20 wt% total elastomer. The impact strength and tensile strength were also measured. It was clear that the addition of ethylene-propylene elastomer grafted maleic anhydride (EPM-g-MA) to PA6/EPM blend could be an effective way for reducing the dispersed particle size, and decreasing the crystallinity. However, for these systems, toughness was not improved significantly in spite of the morphological changes. Blends based on the PA6/EPM/EPM-g-MA (with the ratio of 80/10/10) gave the most beneficial balance between the mechanical properties and morphological parameters; it had the maximum impact strength (52.0 kJ/m²) and the most homogeneous elastomeric particle size.

Keywords:

• blend morphology
• compatibilization
• ethylene-propylene elastomer
• mechanical properties
• polyamide 6

Acknowledgments

This work was supported in part by LANXESS Chemical Co. Ltd. (China). The authors sincerely thank Ulrich Frenzel, manager of LANXESS Chemical Co. Ltd. (Germany), for many helpful discussions and thank all the suppliers of raw materials used in this study.