Eckhard Michael Dr Koch

Studies on the reactive polysulfone–polyamide interface: interfacial thickness and adhesion

The reactive interface formed between an immiscible polymer pair, amorphous polyamide (aPA) and functionalized polysulfone (PSU), was studied by ellipsometry. Diblock copolymers were formed in situ by an interfacial reaction between the amine-terminated aPA and the end-functionalized PSU, whereas graft copolymers were formed between the amino-chain end groups of aPA and the PSU functionalized in the middle of the chains. It was found that the interfacial reaction significantly increased the interfacial thickness, even reaching the size larger than the coil size of the copolymers formed at the interface. The interface structure and the properties were affected by the position and type of functional groups incorporated to the PSU. The reactive interface resulting in the graft copolymers tended to be thicker than that forming the block copolymers. However, the thinner interface demonstrated a superior adhesion to the thicker interface.

Reactive blending of polysulfone with polyamide: a potential for solvent-free freparation of the block copolymer

Abstract Reactive blending of polysulfone (PSU) and polyamide 6 (PA) was carried out at 20:80 (PSU-PA) wt. ratio using a gram-scale mixer (Mini-Max Molder). Three PSUs with different functional groups were prepared and used: maleic anhydride-grafted PSU (PSU-MAH), carboxylic acid-grafted PSU (PSU-COOH) and phthalic anhydride-terminated PSU (PSU-PhAH), having almost same molecular weight ( M w = ca. 20 k) and functional group content (ca. 90 μmole g −1 ). The change in PSU particle size with mixing time was investigated by light scattering and transmission electron microscopy. As expected, all reactive systems yielded finer particles via faster size reduction process, compared with non-reactive system. Attainable particle diameters were: ca. 1 μm for non-functionalized PSU, ca. 0.6 μm for PSU-MAH, 0.3 μm for PSU-COOH, and ca. 40 nm for PSU-PhAH. The particle size of PSU-PhAH system was comparable to that in a pre-made block copolymer synthesized by solution polymerization, suggesting a potential for the solvent-free preparation of PSU-PA block copolymer when adequate reactivity and molecular architecture are provided in reactive blending.