Investigations on the formation of composites by injection molding of PA6 and different grafted polypropylenes and their blends

• Published in: Journal of applied polymer science Vol. 100; no. 4; pp. 2992 - 2999
• Main Authors: Nagel, Jürgen, Scheidler, Doreen, Hupfer, Bernd, Bräuer, Matthias, Pleul, Dieter, Vogel, Claus, Lehmann, Dieter, Amesöder, Simon
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Subscription Services, Inc., A Wiley Company 15.05.2006; Wiley
• Subjects: Applied sciences; composites; Exact sciences and technology; injection molding; Injection moulding; Machinery and processing; Moulding; Plastics; polyamides; Polymer industry, paints, wood; polyolefin; reactive processing; Technology of polymers; Acrylic acid ester; Polymer blends; Two component molding; Propylene polymer; polyolefin; Mechanical properties; Interdiffusion; reactive processing; Organic anhydride; Experimental study; Property processing relationship; Functional polymer; Heterogeneous mixture; composites; Amide 6 polymer; polyamides; Aliphatic polymer; Injection molding; Olefin polymer; Interface reaction; Compatibility; Rheological properties
• ISSN: 0021-8995; 1097-4628
• DOI: 10.1002/app.22983

Blends of different types of polypropylenes (PP) with polyamide 6 (PA6) were produced by extrusion. The PPs used were a PP homopolymer, a maleic anhydride‐grafted homopolymer, and an acrylic acid‐grafted homopolymer. The blends were characterized by DSC measurements, selective extraction, infrared spectroscopy, REM microscopy, melt rheology, and their mechanical properties. Three types of interactions in the blends as well as in two‐component composites mold by the core‐back process could be identified. Blends of PP with PA6 were not compatible, and two‐component bars could not be produced. Blends of PPgAA and PA6 were made compatible during reactive extrusion. Two‐component bars could be produced only with a blend containing 50 wt % PA6. The composite formation was based on the interdiffusion of PA6 in both components and the reactive compatibilization in the blends. Blends of PPgMAn were also compatibilized during reactive extrusion. The composite formation on two‐component injection molding was based on two mechanisms: the interdiffusion at sites, where PA6 chains of both the components came into contact, and an interfacial reaction, where PPgMAn and PA6 came into contact. The interfacial reaction was supported by the high mobility of the first component at the temperature of the melt of the second component. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2992–2999, 2006