The Polymer and Colloids Group
Our main interest in polymer blends is to try to understand how the characteristics of the interfaces between the components affect their properties. This is a target for our ET experiments. We are also interested in exploring how laser confocal fluorescence microscopy (LCFM) can help one to understand how flow fields that operate during the processing of blends can affect morphology.
These interests come together in a project we work on in collaboration with Visteon and DuPont Canada on the paintability of plastic automotive parts. These parts are fabricated from blends of isotactic polypropylene (iPP) and a second polyolefin, typically an ethylene copolymer that serves as an impact modifier. These blends are called 'thermoplastic polyolefins" (TPO). Paint has poor adhesion to low energy polymer surfaces. To get paint to stick to these parts, they have to be coated with a different polymer to act as an adhesion promoter. Within the industry, there is a belief that with a deeper understanding of interfaces in these systems, better adhesion can be achieved with less tendency for paint failure.
We study chlorinated polyolefins (CPO) as adhesion promoters for TPOs that contain crystalline ethylene-butene (EB) copolymers as the dispersed phase. [see Polymer, 46, 11,610-11,623 (2005).] This is a high modulus TPO designed for high strength and light weight. Over the short term, we have been using LCFM to study how processing conditions affect morphology of these blends. [see J. Polym. Sci,. Part B: Polym. Phys., 40, 2842-2859 (2002).] Over the longer term, we will use ET to try to study the interfaces that exist in CPO-coated TPO.