PAULA DOS SANTOS TEIXEIRA

PAULA DOS SANTOS TEIXEIRA

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Irradiation of cellulosic waste from annatto seeds (Bixa orellana L.) for application in polymeric composites
2017 - TEIXEIRA, PAULA dos S.; MOURA, EDUARDO de; GERALDO, AUREA B.C.
The study o f natural vegetable, fiber reinforced polymeric composites became popular in the last decades since because this type of material enables the reduction of both the biomass waste and the cost of the final polymer product (MARINELLI, 2008). Plant fibers are plenty, low cost, they feature biodegradability and renewability. Moreover, cellulose polymer composites are more resistant to flection and impacts than the same base polymer material (FONSECA, 2005; HILLIG, 2008). Specifically, cellulose from annatto seed s is present in concentration at around 40 45%, which becomes important for industrial use (ANSELMO, 2008). In this work, the bagasse from annatto seeds after reddish pigment removal has being used to obtain high density polyethylene (HDPE) composites. T he original raw material underwent a pretreatment that extracted the components from seeds such as residue of remaining pigment, sugars, proteins and acid fats. The remaining fibers have been dried and mashed, and then submitted to electron beam irradiatio n with doses of 30 kGy, 50 kGy and 70 kGy to verify the effect of the radiation on the cellulose structure and its subsequent effect on the incorporation into polymer matrix. The study covered the extrusion of these fibers (irradiated and non irradiated) i n the ratio of 1 % to 5 % with HDPE. The sample characterization has been done by infrared spectrometry (FTIR), thermal degradation (TG) and mechanical tensile tests. The results are then discussed.
Irradiação da biomassa de sementes de urucum (Bixa orellana L.) para aplicação em compósitos poliméricos
2017 - TEIXEIRA, PAULA dos S.; MOURA, EDUARDO de; GERALDO, AUREA B.C.
Study of bixin oxidation by ionizing irradiation
2017 - FONSECA, THAIS N.; TEIXEIRA, PAULA S.; MOURA, EDUARDO de; GERALDO, AUREA B.C.
Brazil is the world's largest producer of anatto, followed by Kenya and Peru. The fruit of the annatto tree is constituted by a capsule containing external spines and internal seeds with reddish coloration, providing a natural pigment which is environmentally efficient, being able to replace synthetic pigments and dyes. The active substance of the pigment is Bixin, which is a type of carotenoid which constitutes a greater percentage of pigment in these seeds and has a lipo soluble character. Bixin reacts with NaOH in a saponification reaction giving norbixin, which is water soluble. It is known that the destination of the dye extracted from the fruit is intended for industry, especially the food industry. The culture of annatto tree brings prospects of development in agricultural programs for medium and small producers, which are able to use decadent areas of other crops. In addition to the food sector, new applications for the pigment helps the development of family farming. The pigment extracted from annatto undergoes a natural oxidation; this work aims to evaluate this phenomenon and also the oxidation of the pigment after the irradiation process. This work also evaluates of the how the oxidation process is affected by irradiation and the modifications introduced to irradiated pigments. Irradiated and nonirradiated samples were characterized by thermogravimetry, UV-vis spectrophotometry and infrared spectroscopy (FTIR). The results are then discussed.
Irradiação da biomassa lignocelulósica de sementes de urucum (Bixa orellana L.) para aplicações em compósitos poliméricos
2017 - TEIXEIRA, PAULA S.; FONSECA, THAIS N.; MOURA, EDUARDO de; GERALDO, AUREA B.C.
O estudo de compósitos poliméricos reforçados com fibras vegetais tem se tornado popular nas últimas décadas já que este tipo de material possibilita a redução tanto do rejeito de biomassa como o custo final do produto polimérico. Fibras vegetais existem em grande quantidade, são de baixo custo e conjugam biodegradabilidade e renovação. Além disso compósitos de polímero-celulose são mais resistentes à flexão e ao impacto que o mesmo material exclusivamente feito em polímero. Especificamente a celulose contida nas sementes de urucum está presente em uma concentração em torno de 40-45 %, o qual torna-se importante para o uso industrial. Neste trabalho, o bagaço das sementes de urucum após a remoção do seu pigmento avermelhado foi usado para obter compósitos de polietileno de alta densidade (PEAD). O material original foi usado sem e com um prétratamento que removeu componentes como o resíduo do pigmento remanescente, açúcares, proteínas e ácidos graxos. As fibras remanescentes foram secas, fragmentadas e submetidas à irradiação por feixe de elétrons nas doses de 10 kGy, 25 kGy, 50 kGy e 75 kGy para verificar o efeito da radiação na estrutura da celulose e seu subsequente efeito na matriz polimérica.