Crystallinity of POM films cast from solution

Summary The process of crystallization and the structure of poly/ oxymethylene/ (POM) films cast from hexafluoroacetone sesquihydrate solutions were studied. The supermolecular structure of thin POM films was studied by the use of polarization microscope. It has been found to consist mainly of spherulites, the size of which are essentially independent of the initial concentration of the solution. Similarly to the findings reported for thin films made of melts, ovoids and spiral ovodis were also found in minor amounts. Two additional formations indicating more complex structure were also detected. Further details of the structures formed could be recognized applying scanning electron microscopy.     

Novel,solvent-based method for the production of polymer sheets with a superhydrophobic surface

We have introduced a novel solvent-based method to roughen polymer surfaces and characterized treated polypropylene (PP). The method consists of three main steps: solvent treatment, drying, and peeling. We investigated the effects of process parameters such as time of immersion in the solvent, solvent temperature, and drying temperature on the surface morphology created. The structure formed on the surface is mainly influenced by solvent temperature and drying temperature. We also characterized the wetting behavior of the surfaces. The patterned surfaces exhibit superhydrophobic characteristics with a high water contact angle (CA) (>155 °) and low water contact hysteresis (<5°). Adding an effective nucleating agent to PP makes it possible to generate outstanding CAs (>160°) and tailor spherulite sizes. The method is simple and scalable, therefore this superhydrophobic material is easy to mass-produce.