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In this research, an attempt was made to improve compatibility in a polymer blend composed of incompatible constituents, namely, recycled polystyrene (rPS) and polystyrene-co-acrylonitrile (SAN), through the addition of a compatibilizer. The compatibilizing agent, styrene-ethylenebutadienestyrene block copolymer (SEBS), was added to the polymer blend in ratios of 5 and 10 wt%. For this purpose, blends of rPS and SAN at different ratios, without and with varying concentrations of compatibilizer, were prepared by melt blending using a co-rotating twin-screwextruder. Mechanical properties including tensile and impact strength, rheological properties (RPA), thermal behaviour (DSC) and morphological characteristics (SEM) were evaluated. According to the results obtained by complex viscosity, the blends behave as a pseudoplastic fluid. The results showed that the addition of SEBS increased the Izod impact strength and the elongation at break and decreased the tensile strength and tensile modulus. rPS/SAN blend modified with SEBS had better mechanical properties than the rPS/SAN alloy. SEM photographs revealed that the SEBS was not only distributed in the SAN phase but also distributed in rPS phase in rPS/SAN/SEBS blend. Furthermore, DSC analysis for blends of rPS/SAN gave a good indication of the improvement on miscibility for most compositions. SEM micrographs of tensile fracture surfaces indicated that the formation of the co-continuous phase and the improvement of interface adhesion are the most important reasons for the excellent tensile properties of the rPS/SAN/SEBS blends. Within the range of analysed compositions, the morphologies investigated by SEM are typical of immiscible blends., K.B. would like to thank Dr Maria del Pilar Posadas Bernal, Dr Patricia Sampe- droTejedor and Grupo de Elastomeros for their help in hosting him as a doctoral student to carry out the experimental part of his PhD thesis at the Elastomeros laboratory, Instituto de Ciencia y Tecnologia de Polimeros (ICTP-CSIC) Madrid, Spain. This research was funded by Spanish Ministry of Science and Innovation (MINECO) through the research projects RTI2018-096636-J-100 and PID2020- 119047RB-100.

Supplemental Material for Polyurethane tissue adhesives for annulus fibrosus repair: Mechanical restoration and cytotoxicity by Lucas Dall Agnol, Fernanda Trindade Gonzalez Dias, Natália Fontana Nicoletti, Daniel Marinowic, Sidnei Moura e Silva, Angel Marcos-Fernandez, Asdrubal Falavigna and Otávio Bianchi in Journal of Biomaterials Applications

The present study aimed to investigate the effect of structure (design and porosity) on the matrix stiffness and osteogenic activity of stem cells cultured on poly(ester-urethane) (PEU) scaffolds. Different three-dimensional (3D) forms of scaffold were prepared from lysine-based PEU using traditional salt-leaching and advanced bioplotting techniques. The resulting scaffolds were characterized by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), mercury porosimetry and mechanical testing. The scaffolds had various pore sizes with different designs, and all were thermally stable up to 300 degrees C. In vitro tests, carried out using rat bone marrow stem cells (BMSCs) for bone tissue engineering, demonstrated better viability and higher cell proliferation on bioplotted scaffolds compared to salt-leached ones, most probably due to their larger and interconnected pores and stiffer nature, as shown by higher compressive moduli, which were measured by compression testing. Similarly, SEM, von Kossa staining and EDX analyses indicated higher amounts of calcium deposition on bioplotted scaffolds during cell culture. It was concluded that the design with larger interconnected porosity and stiffness has an effect on the osteogenic activity of the stem cells. Copyright (c) 2013 John Wiley & Sons, Ltd.

Este documento trata de explicar los conceptos generales de la química del poliuretano en la construcción y, en especial, en los pavimentos continuos de resina de poliuretano bicomponente al agua. Es un sistema ampliamente conocido, pero con un mercado cambiante, que está en constante renovación y buscando mejores soluciones a diferentes sistemas que utilizan resinas de poliuretano. Las formulaciones y aditivos mencionados dan una de idea de la finalidad que se busca en este tipo de pavimentos, especialmente desarrollados para industrias alimentarias y químicas. Se darán a conocer los diferentes sistemas de utilización de poliuretanos y su finalidad, objetivos y el motivo por el que se usan para realizar recubrimientos continuos., This document tries to explain the general concepts of the chemistry of polyurethane in construction and, especially, in continuous pavements of bicomponent water-based polyurethane resin. It is a well-known system, but with a changing market, which is constantly being renewed and looking for better solutions to different systems that use polyurethane resins. The mentioned formulations and additives give an idea of the purpose that is sought in this type of flooring, especially developed for food and chemical industries. The different systems for using polyurethanes and their purpose, the objectives and the reason behind their use in continuous coatings, will be described.