JEC COMPOSITES MAGAZINE - Issue #45 - November/December 2008 - 28

FEATURE “Automotive” Innovative “green plastic” nanotechnologies Two new nanotechnologies were recently launched to meet the automotive sector’s need for parts with improved ductility and for reduced solar radiation transmission in glazing applications. This article describes the first of these, a new "high modulus ductile" technology. fillers, in a PC/PBT substrate, improve some mechanical characteristics of the unfilled material, they also degrade one of the most crucial properties for automotive body panels or components, which is impact-resistance behaviour. Typically, PC/PBT blends display a tensile modulus around 2 GPa and notched Izod impact strength of over 500 joules/m. In the quest for higher modulus materials, mineral fillers are usually added, but this also reduces the impact performance. For example, a PC/PBT blend with 15% mineral filler has a 3.5 GPa modulus, but reduced impact strength of only around 80 joules/m. Adding extra impact modifier can help, but at the expense of a lower tensile modulus. Nano-structure network Xenoy* HMD Mineral filler(s) LIONEL RAUSER, PLATFORM MANAGER FOR AUTOMOTIVE OEMS, SABIC INNOVATIVE PLASTICS or a number of years, SABIC Innovative Plastics (formerly GE Plastics) has been conducting research into nanotechnologies to enhance the performance of engineering plastics. The first nanotechnology product, a conductive Noryl GTX* PPO/PA alloy used for the manufacture of automotive mirror housings, came onto the market around 1992. Since the European regulation to lower CO2 emissions was proposed, car producers have been demanding lighter material solutions. SABIC Innovative Plastics has developed several solutions, such as the Xenoy* products, for outside body panels and large components. Nanostructure network Fig. 2: The nano-structure network within Xenoy iQ* HMD gives this material unique ductile properties. Fig. 1: Morphology of phase-separated Xenoy* PC/polyester blend. High modulus ductile (HMD) technology changes this paradigm, enabling higher modulus and impact strength at the same time. High stiffness is achieved by the use of mineral fillers as in traditional PC/PBT blends, and a nano-structure network has been introduced for additional impact performance (Fig. 2). Stiffness, impact resistance and gap and flush management are three of the most critical parameters requested by OEMs for large components and body parts. The following data show the contribution of the SABIC Innovative Plastics technology to these performance requirements in automotive applications. In Xenoy* materials, each different component contributes to Unfilled thermoplastic materials have lower stiffness and are more influenced by temperature variations than steel or thermosets, as can be seen when comparing their CLTE (coefficient of linear thermal expansion). Material producers usually add fillers, either glass or mineral, to overcome this limitation in thermoplastics (and in the final product). But some fillers create aesthetic surface issues in large body parts. To obtain class A surface appearance after painting, mineral fillers have been preferred over the past years. However, while such jec composites magazine / No45 November-December 2008

JEC COMPOSITES MAGAZINE - Issue #45 - November/December 2008

Table of Contents for the Digital Edition of JEC COMPOSITES MAGAZINE - Issue #45 - November/December 2008