Abstract Quantification of elastomer content for the ethylene-propylene diene monomer/polybutadiene blend are seldom subjects in the literature, mainly due to rubber compatibility problems. However, suitable blend contents can lead to desirable properties. Infrared spectroscopy can quantify this type of blend even if some bands overlap, which can be resolved with the proper choice of spectrum obtaining mode and non-overlapping analytical bands. This study evaluates the ethylene-propylene diene monomer/polybutadiene blend quantification by transmission, reflection and transflectance infrared. Even though all of the methodologies showed satisfactory results, transmission mode provided better accuracy. The methodology is simple and suited for the rubber industry. The sample with the higher BR content provided the best result. The band at 743 cm-1 is weak and results in even weaker absorptions when measuring samples with low BR content. On the other hand, the developed methodologies provided an accurate determination of low EPDM contents. For infrared spectroscopy researchers, these results not only encourage using different spectra obtaining modes application, including less conventional ones such as transflectance in the near infrared region for quantitative determination, it also contributes to a wide discussion of errors in the developed methodologies, which are also seldom discussed in publications.

Abstract A considerable number of papers have been published to assess self-healing capacity of several materials, as well as several applications in different areas. However, the impact assessment of changing synthesis parameters of microcapsules, hollow fibers or microvascular systems in its final physicochemical properties are still an emerging research field. This current paper presents a synthesis process of PU microcapsules containing TDI as core agent and the characterization of microcapsules physicochemical properties. During the synthesis, the reaction parameter stirring speed was changed to assess the impact that this parameter has in the final microcapsules’ physicochemical properties. Microcapsules were characterized by FT-IR, TGA and image analysis (OM and SEM). Additionally, microcapsules were incorporated to an epoxy matrix (5% weight/weight) to assess the impact in the final physicochemical and mechanical matrix properties. Epoxy-based test specimens were also obtained within aramid and silica, which are traditional reinforcing loads in rubber synthesis. Final mechanical properties of matrixes within aramid and silica were compared to the properties of matrixes within microcapsules to determine what kind of behavior the microcapsules have when incorporated to epoxy matrixes.

Abstract This study describes a methodology to prepare and characterize PUF [poly(urea formaldehyde)] microcapsules containing 5-ethylidene-2-norbornene (ENB) as self-healing agent, as well as the compatibility evaluation of ENB in the presence of Grubb’s catalyst with an epoxy matrix. First, the results of an adhesion assay by lap shear proved chemical compatibility between the epoxy matrix and self-healing agent in the presence of Grubb’s catalyst. After evaluating the chemical compatibility, microcapsules with ENB were synthesized in an oil-in-water emulsion system. Thereafter, the microcapsules were morphologically, chemically and thermally characterized in which a granulometric dispersion between 30-140 μm and an average size of 69.8 ± 4.9 μm were observed. The SEM (scanning electron microscope) results showed that the average thickness of microcapsules shell was 3.6 ± 0.4 μm. The thermogravimetric analysis (TGA) showed that microcapsules are susceptible to rupture and consequent ENB release in temperatures greater than 230 °C, demonstrating that microcapsules are suitable for applications in materials with self-healing capacity.