Ultrapolymers: New plastomer for direct processing or PP modification

A recent addition to Ultrapolymers’ portfolio of high performance polymers is LyondellBasell’s Koattro KT AR05 plastomer for direct processing or use as a modifying agent for polypropylene. Uncured and without the need for any plasticiser, this material combines high flexibility (bending stiffness 20 MPa) with an outstanding low compression set at high temperatures of 42 % at 70 °C, and a very high level of ductility (elongation at break >400 %). A melt flow rate of 0.5 g/10 min (190 °C, 2.16 kg) and its high melt stability allow this new plastomer to be converted to films, profiles, containers or parts using all common manufacturing processes for thermoplastic polymers. Its low Shore A hardness of 77 results in soft-touch surfaces. PP modified with Koattro KT AR05 shows significantly reduced stress whitening.

In certain applications the new plastomer can substitute styrene-block-copolymers, which have a higher density and, due to their cured molecular structure, are more difficult to recycle. Being non-toxic and approved for food contact, seals and gaskets for closing systems are a large potential area of application. Beyond this, Koattro KT AR05 is well suited to foaming processes, facilitating the manufacture of flexible sheets with a density of 650 g/cm³ and a compression set of only 9.2 % at 23 °C.

When used as modifier for PP, Koattro KT AR05 significantly reduces the material’s stress whitening, compression set, hardness and rigidity, whilst at the same time increasing its elongation at break, toughness, and transparency. This helps, for example, to preserve the shelf appeal of a highly transparent injection moulded or thermoformed container even after rough handling during transport and storage. Similar benefits are gained with flexible automotive parts, which require extensive bending for assembly.

The newly-developed grade KT AR05 is the first commercially available member in a growing family of Koattro plastomers by LyondellBasell. Among other grades to follow is a high flow grade for injection moulding, which is already available for trial purposes. A highly transparent metocene grade is also currently under development.

More Information: www.ultrapolymers.de