Biblioteca do Café
URI permanente desta comunidadehttps://thoth.dti.ufv.br/handle/123456789/1
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Resultados da Pesquisa
Item Disposable coffee capsules as a source of recycled polypropylene(Associação Brasileira de Polímeros, 2020) Domingues, Michel Lincoln Bueno; Bocca, Jean Rodrigo; Fávaro, Silvia Luciana; Radovanovic, EduardoIn this paper was investigated the chemical, physical, thermal, mechanical and morphological characteristics of the recyclable materials obtained of the NESCAFÉ DOLCE GUSTO branded beverage capsules, characterizing different resulting compositions. The characterization was made by following techniques: Fourier-transform infrared spectroscopy (FTIR), X-ray Diffraction (XRD), Differential Scanning Calorimetry (DSC), Thermogravimetric Analysis (TGA), Scanning Electron Microscopy (SEM), Water Absorption and techniques for the analysis of mechanical properties (tensile and impact test). The results showed that the body of the capsule and the inner flter, both made of polypropylene, are the most interesting materials to be reused, having good properties, while the materials resulting from the mixtures of all the constituents in the beverage capsules presented decreased mechanical properties.Item Properties of recycled high density polyethylene and coffee dregs composites(Associação Brasileira de Polímeros, 2013) Cestari, Sibele Piedade; Mendes, Luis Claudio; Silva, Daniela França da; Chimanowsky Jr., Jorge Pereira; Altstädt, Volker; Demchuk, Vitaly; Lang, Anneliese; Leonhardt, Rodrigo Gheno; Keller, Jan-HendrikComposites of recycled high density polyethylene (HDPE-R) and coffee dregs (COFD) were elaborated. The blends were made at the proportions of 100-0, 90-10, 80-20, 70-30, 60-40, 50-50 and 40-60% polymer-fller ratio. The materials were evaluated through scanning electron microscopy (SEM), differential scanning calorimetry (DSC), thermogravimetry/derivative thermogravimetry (TGA), and compressive resistance test. The compounding was done using a two-stage co-kneader system extruder, and then cylindrical specimens were injection molded. All composites had a fne dispersion of the COFD into the polymeric matrix. The composites degraded in two steps. The frst one was in a temperature lower than the neat HDPE, but higher than the average processing temperature of the polymer. The melting temperature and the degree of crystallinity of the composites resulted similar to the neat HDPE ones. The compressive moduli of the composites resulted similar to the neat polymer one. The results show that these composites have interesting properties as a building material.Item Coffee waste biochars: characterization and zinc adsorption from aqueous solution(Editora UFLA, 2019-10) Sertoli, Lindiamara; Carnier, Ruan; Abreu, Cleide Aparecida de; Coscione, Aline Renée; Melo, Leônidas Carrijo AzevedoThe final disposal of organic wastes has become a major challenge with increasing industrialization and population growth. Coffee wastes can be converted into biochar and provide economic and environmental benefits, such as heavy metal remediation in different media. We produced biochars at 700 °C from spent coffee grounds and coffee parchment, characterized them physically and chemically and evaluated their Zn adsorption capacity from aqueous solution. Batch adsorption experiments were performed with six Zn concentrations using four replicates. The desorption process was performed sequentially with a pH 4.9 buffer acetic acid solution. Langmuir and Freundlich isotherms were fitted to the adsorption data using non-linear models. Results show that both biochars are alkaline and have high values of point of zero charge (PZC) (9.2 and 7.7 for coffee parchment and spent coffee grounds biochar). These characteristics indicate precipitation as the main mechanism of Zn immobilization and may have contributed to the low adsorption capacity obtained (0.056 and 0.792 mg g-1 for spent coffee ground and coffee parchment biochar, respectively). Although the biochars have shown low adsorption capacity, they bound Zn strongly and the adsorption process is not easily reversed.