Improving the Mechanical Performance of LDPE/PP Blends through Microfibrillation

Polyolefins (polyethylene (PE) and polypropylene (PP)) are the most abundant polymers found in plastic solid waste. They are expensive to separate, and recycling them in the form of blends is not viable due to their immiscibility and incompatibility. Following the idea of the circular economy where waste is turned into raw materials for manufacturing technological products using minimum energy, a solution is proposed for the poor behavior of immiscible PE/PP blends by taking advantage of their immiscibility to transform them into microfibrillar composites (MFCs). PE/PP blends with an 80:20 content ratio were studied, emulating the ratio found in municipal waste. A microfibrillar structure was achieved through an unusual combination of common industrial processing techniques: Extrusion, drawing, and injection. The performance of the resulting fibrillar materials was evaluated by means of tensile, fracture, and impact tests, and the results were compared with those of unstretched blends (UBs) with droplet morphology. The effect of adding a compatibilizer was also evaluated. The results were promising as the performance of the MFCs was much better than that of the nonfibrillated blends, and a synergistic effect between the addition of the compatibilizer and microfibrillation process was observed. It seems that this type of processing has great potential for large-scale application in immiscible recycled polyolefin blends in which the final properties can be improved by modifying their morphology, obviating the need to separate these polymers in mixed waste streams.Fil: Rosales, Caren Soledad. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; ArgentinaFil: Aranburu, Nora. Universidad del Pais Vasco. Polymat.; EspañaFil: Otaegi, Itziar. Universidad del Pais Vasco. Polymat.; EspañaFil: Pettarin, Valeria. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; ArgentinaFil: Bernal, Celina Raquel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Tecnología en Polímeros y Nanotecnología. Universidad de Buenos Aires. Facultad de Ingeniería. Instituto de Tecnología en Polímeros y Nanotecnología; ArgentinaFil: Müller, Alejandro J.. Universidad del Pais Vasco. Polymat.; EspañaFil: Guerrica Echevarriá, Gonzalo. Universidad del Pais Vasco. Polymat.; Españ

New radial velocity observations of AH Her : Evidence for material outside the tidal radius

The authors acknowledge financial support prom PAPIIT project IN114917. JER acknowledges support from a ‘Leids Kerkhoven-Bosscha Fonds’ (LKBF) travel grant to visit the API at UvA. LJS and ARM would like to thank DGAPA, UNAM for financial support provided by Programa de Apoyo a Proyecto de Investigacion e Inovacion Tecnologica (PAPIIT) projects IN102517andIN102617. JVHS acknowledges support from an STFC grant ST/R000824/1.Spectroscopic observations of AH Herculis during a deep quiescent state are put forward. We found the object in a rare long minima, allowing us to derive accurately the semi-amplitudes: K1 =121 ± 4 km s-1 and K2 = 152 ± 2 km s-1 and its mass functions MWsin 3i = 0.30 ± 0.01 M⊙ and MRsin 3i = 0.24 ± 0.02 M⊙, while its binary separation is given by asin i = 1.39 ± 0.02 R⊙. The orbital period Porb = 0.25812 ± 0.00032 d was found from a power spectrum analysis of the radial velocities of the secondary star. These values are consistent with those determined by Horne, Wade & Szkody. Our observations indicate that K5 is the most likely spectral type of the secondary. We discuss why we favour the assumption that the donor in AH Her is a slightly evolved star, in which case we find that the best solution for the inclination yields i = 48° ± 2°. None the less, should the donor be a ZAMS star, we obtain that the inclination is between i = 43° and i = 44°. We also present Doppler tomography of H α and H β, and found that the emission in both lines is concentrated in a large asymmetric region at low velocities, but at an opposite position to the secondary star, outside the tidal radius and therefore at an unstable position. We also analyse the H α and H β line profiles, which show a single broad peak and compare it with the previous quiescent state study that shows a double-peaked profile, providing evidence for its transient nature.Publisher PDFPeer reviewe