Regensburg 2019 – wissenschaftliches Programm
CPP 25.18: Poster
Dienstag, 2. April 2019, 14:00–16:00, Poster B1
Characterization of interfaces in coextruded polypropylene-based multilayer structures via confocal Raman spectroscopy — •Claudia Leimhofer1, Sabine Hild1, and Elias Mayrhofer2 — 1Institute of Polymer Science, Johannes Kepler University, Linz, Austria — 2Institute of Polymer Extrusion and Compounding, Johannes Kepler University, Linz, Austria
Co-extrusion of polymers is a powerful tool to produce multilayer composites that combine properties which cannot be achieved by pure substances alone. The strength of the total composite is determined by the adhesion between the adjacent layers. The polyolefines used in industrial applications often are non-polar and show low surface free energy which impairs the overall adhesion. Different adhesion mechanisms for polymers were proposed in the literature. One widely accepted model is based on interdiffusion of the materials and the formation of an interface layer. The aim of the study is to characterize the interdiffusion layers of a co-extruded polypropylene-based composite by confocal Raman spectroscopy. With Raman spectroscopy, the chemical composition of the substances in the bulk layers as well as at the interface can be determined. In the characterized seven-layered systems, a polyethylene- and vinyl alcohol-based barrier layer is combined with a maleic acid grafted polypropylene adhesive, pure polypropylene and a regrind material. The different layers can be clearly differentiated, and the presence of interface layers with spectral properties deviating from the pure substances can be observed.