Mahboobeh Attei and Inês Lino graduate with a M.Sc.

Congratulations to Mahboobeh and Inês who graduated, in Dec. 2017, with the following M.Sc. theses:

"Microencapsulation of isocyanate compounds for autoreactive, monocomponent adhesive", by Mahboobeh Attaei. Supervised by Ana C. Marques, in collaboration with CIPADE S.A.

Abstract: The objective of this thesis is the microencapsulation of isocyanate based adhesive material used in footwear industries with the idea of reducing the risk of handling of toxic isocyanate. The interfacial polymerization method was the one selected to produce microcapsules (MCs), with a shell of polyurea (PUa)and/or polyurethane (PU) and containing in their core different isocyanate compounds e.g. isophorone diisocyanate (IPDI), toluene diisocyanate (TDI) and mixtures of monomeric and polymeric species of methylene diphenyl diisocyanate (MDI). In this work, a general processing method was carried out by: i) formation of an oil-in-water emulsion; ii)formation of PU and/or PUa shell at the interface of the oil-water domains; iii) filtration and washing of MCs to remove the excess of reactants; iv) drying at room temperature (RT).Fourier transformed infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA) were employed to characterize the MCs in what concerns the presence of free -NCO groups and, therefore, the successful encapsulation of isocyanate compounds. Scanning electron microscopy (SEM) was used to study the morphology of the MCs, i.e. to check if they exhibit a core-shell structure. Finally, peeling strength tests were carried out at different conditions of temperature and pressure, to study the interaction of MCs with the polyol-based component and the MCs behavior, in terms of isocyanate release.

"Natural origin precursors for carbon fiber production", by Inês Lino. Supervised by Ana C. Marques and Dr. Paulo Correia, in collaboration with FISIPE S.A. from the SGL Group

Abstract: Carbon fibers are bundles of flexible, lightweight and thin filaments composed mostly by carbon atoms, high in tensile strength, that can be used in a wide range of high performance applications, such as in the aerospace and automotive industry, textiles and modern sports equipment. Carbon fibers’ raw materials are denominated precursors, being polyacrylonitrile (PAN) the most used one. Most carbon fiber precursors have fossil origin and due to oil price oscillations, environmental problems, and precursor cost, carbon fibers are considered expensive materials. In the present work, to reduce the above-mentioned problems and, consequently, the cost of carbon fibers, a natural and sustainable source material, cardanol, was used in the production of two different compounds, a polymer (polycardanol) and a prepolymer (cardanol-based vinyl ester resin), which were investigated as precursors to produce more economically sustainable and more eco-friendly carbon fibers. Both polycardanol and cardanol-based vinyl ester (VE) resin were characterized using several methods: Attenuated Total Reflectance - Fourier Transformed Infrared Spectroscopy (ATR-FTIR), Nuclear Magnetic Resonance Spectroscopy (NMR), Thermogravimetric Analysis (TGA), Differential Thermal Analysis (DTA) and Differential Scanning Calorimetry (DSC). Through these methods, it was possible to conclude that the synthesis of polycardanol was not as efficient as that of the prepolymer, making the latter a more promising material as a future carbon fiber precursor.