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Porous and Non Porous Transparent PEEK-WC Films

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  Academic Journal of Polymer Science - Juniper Publishers                                                                     Abstract Membrane technology offers a wide range of applications and advantages in many fields. On the other hand, PEEK-WC is widely employed to produce membranes, also after chemical modifications, with different morphologies and different techniques, and for many applications. In this work transparent PEEK-WC membranes were produced, modifying just the preparation conditions. Transparent membranes find a lot of applications, from display protection film, in odontology, as impermeable pellicles, in cultural heritage protection, but also in traditional fields, as gas separation. Not all the membranes are transparent, but it seems clear that the oxygen presence during membrane formation is responsible of non transparence of the PEEK-WC membranes. Our membranes result optically transparent, also when their thickness is not so thin. By means of contact angle measu

Investigation of Extensional Flow Behavior of Polyethylene Melts through Birefringence by using Extrusion Cross-slot Die

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  Academic Journal of Polymer Science - Juniper Publishers                                                            Abstract Flow parameters of polymers melt under steady state condition in shear are required to assess flow behaviour of the molten material in the die or downstream operations. Very often this is not sufficient to have a full understanding of the polymer processability, and additional information of flow response in extension is also needed. In this paper, the extensional properties of two molten polyethylene have been investigated by measuring stress response when a high extensional deformation is applied in a cross-slot die. Flow induced birefringence analysis and stress-optical rule are applied to determine rheological properties. Two polyethylene’s with similar rheology in shear but different molecular structure (HDPE and LLDPE) are analysed. Very interestingly, this approach appears capable of capturing differences in extensional flow that are not detectable using

Manufacturing and Evaluation of High-Quality Composites using Out-of-Autoclave Prepreg - Juniper Publishers

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  Academic Journal of Polymer Science - Juniper Publishers Abstract Carbon fiber-reinforced thermoset polymers have become popular in a wide variety of applications such as primary aerospace structures, sporting goods and wind energy systems. Autoclave processing has been the preferred method for fabricating high performance composites. However, the need for low-cost, high-performance composites prompted researchers and industries to develop new techniques such as vacuum aided resin transfer molding (VARTM) and vacuum-bag-only cure out-of-autoclave (OOA). Manufacturing parts with less than 1% void content, on the other hand, remains a difficulty. In the present study, the OOA technique was used to create high-quality (less than 0.25 percent void content) carbon/epoxy composites. The phases in the processing that result in good quality are described. Physical, mechanical, and fatigue properties of the manufactured composites were evaluated. Keywords:  Fiber-reinforced; Polymers; Carbon;