Engineering polymers with uniform crystallisable units: Segmented copolymers based on poly(2,6-dimethyl-1,4-phenylene ether)

The importance of polymer materials as construction materials is continually growing. Polymers are a cheap and light alternative to conventional materials used for construction. In the automotive industry there is a specific need for materials with a high modulus up to a high glass transition temperature (Tg) (~200°C), good processability and excellent chemical resistance. Therefore the material should be semi-crystalline and crystallise fast upon cooling from the melt. Polymer systems with a high Tg, a not too high melting temperature (Tm) and thus a high Tg/Tm ratio are thought to fulfil these requirements. Noryl-GTX®, a blend of poly(2,6-dimethyl-1,4-phenylene ether) and polyamide-6,6 approaches the required properties. However a high polyamide content (40%) is necessary in order to obtain enough crystallinity. The PPE and polyamide phase separate and the polyamide phase is semicrystalline with a Tg at 70°C. The aim of the work described in this thesis is to study the synthesis and structure-property relationships of semi-crystalline segmented copolymers with a high Tg (>150°C), high Tm (250-300°C) and high Tg/Tm ratio (around 0.8). These segmented copolymers will be based on poly(2,6-dimethyl-1,4-phenylene ether) (PPE) as amorphous segment and uniform tetraamide units as crystallisable segment. It is expected that this novel high Tg polymer crystallises fast from the melt, has a good solvent resistance and is transparent. Such a material may serve as an alternative to known engineering polymers systems e.g. for use as or in construction materials in high temperature applications.