O uso de fibras vegetais como carga de reforço em compósitos de matriz polimérica está recebendo crescente atenção devido às propriedades obtidas no produto final, podendo substituir cargas convencionais como fibras de vidro. Associado a isto, o emprego de polímeros pós-consumo em produtos com maior valor agregado desperta o interesse econômico, social e ambiental. Neste sentido, o presente estudo tem por objetivo avaliar a reciclagem do poliestireno expandido (EPS) para obtenção de compósitos com a incorporação de fibra de curauá. Inicialmente foram desenvolvidos compósitos de poliestireno virgem (PS) reforçado com fibras de curauá, considerando a influência do teor de fibra, da adição de agente de acoplamento (à base de anidrido maleico) e o efeito da remoção da casca da fibra, a fim de selecionar a melhor formulação. O poliestireno expandido, proveniente das centrais de triagem do município de Caxias do Sul, foi reciclado em um equipamento que consiste de moagem e passagem por uma rosca aquecida a 100 °C, sendo avaliado o efeito deste processo nas suas propriedades morfológicas, térmicas, mecânicas e reológicas. A formulação previamente selecionada com matriz de PS foi empregada para a matriz de poliestireno reciclado (rEPS). Os compósitos foram obtidos por meio de uma pré-mistura em extrusora monorrosca, seguida de extrusão em duplarrosca e moldagem por injeção. Os compósitos obtidos foram avaliados com relação a sua morfologia (MEV), identificação dos grupos funcionais (FTIR), resistência mecânica (tração e impacto), comportamento térmico (TGA e HDT), reológico (viscosidade e índice de fluidez) e degradação em solo simulado e sob radiação UV. Os resultados demonstraram que a reciclagem do EPS não tem influência significativa nas propriedades do material em comparação com o PS utilizado como referência, viabilizando assim o processo de reciclagem empregado. Melhores propriedades foram obtidas para o compósito em matriz virgem utilizando 20% em massa de fibra de curauá sem casca, contendo 2% em massa de agente de acoplamento. Com a utilização da matriz reciclada constatou-se uma diminuição da resistência à tração em relação aos compósitos com matriz virgem, já as demais propriedades (resistência ao impacto, TGA, HDT e reologia) os compósitos com matriz reciclada apresentaram propriedades superiores. A morfologia dos compósitos com matriz virgem ou reciclada foi similar, porém, em presença do agente de acoplamento foi possível constatar uma maior interação fibra/matriz empregando a matriz virgem. Nos ensaios de biodegradação em solo simulado e sob radiação UV constatou-se que a presença da fibra, juntamente com o agente de acoplamento, não impediu a degradação do material, caracterizada pela existência de bandas na região da carbonila no spectros de FTIR. Entretanto, pela análise morfológica não foi observado formação de trincas, fissuras e de biofilme nas amostras submetidas à biodegradação em solo, contudo, trincas e fissuras foram constatadas durante o envelhecimento sob radiação UV, sendo este efeito menos pronunciado em presença do agente de acoplamento. Em ambos os ensaios de degradação foi verificado que a presença da fibra de curauá retarda o processo de degradação da matriz, quando avaliada por meio da sua resistência à tração. Concluiu-se que a reciclagem do EPS viabiliza sua utilização na obtenção de compósitos com fibras vegetais, diminuindo os impactos ambientais gerados com seu descarte. Adicionalmente ficou comprovado que compósitos de poliestireno reforçados com fibra de curauá apresentam boas propriedades, podendo ser utilizados como material de engenharia. / Conselho Nacional de Desenvolvimento Científico e Tecnológico / The use of vegetable fibers as a reinforcing filler in polymer composites is receiving increased attention because of the good properties obtained in the final material and they are able to substitute conventional fillers such as glass fibers. Associated with this, the use of post-consumer polymers in products with higher value aggregate has economic, social and environmental interest. In this regard, this study aims to evaluate the recycling of expanded polystyrene (EPS) to obtain composites with the incorporation of curaua fiber. Virgin polystyrene composites (PS) reinforced with curaua fiber were initially developed considering the influence of the fiber content, the addition of coupling agent (based on anhydride maleic) and the effect of removing the shell fiber in order to select the best formulation. Expanded polystyrene from the central from the triage of the city of Caxias do Sul, was recycled into a device that consists of grinding and pass through screw heated to 100 °C, and the effects of this process in their morphological, thermal, mechanical and rheological properties were evaluated. The formulation previously selected to the PS matrix was used for the recycled polystyrene (rEPS) matrix. The composites were obtained using a pre-mixing in a single-screw extruder, followed by a twin-screw extruder and injection molding. The composites were evaluated in relation to their morphology (SEM), identification of functional groups (FTIR), mechanical strength (tensile and impact), thermal behavior (TGA and HDT), rheological (viscosity and melt flow index) and degradation in simulated soil and under UV radiation. The results showed that the recycling of EPS has no significant influence the material properties in comparison with the PS used as reference, thus enabling recycling process employed. Best properties were obtained for composite with virgin matrix using 20wt% curaua fiber shelled, containing 2wt% of coupling agent. With the use the recycled matrix noted a decrease in tensile strength compared to virgin matrix composite, since the other properties (impact strength, TGA, HDT and rheology) the composites with recycled matrix showed superior properties. The morphology of the composite was similar for virgin and recycled matrices, but in the presence of coupling agent it was possible to see more interaction fiber/matrix using the virgin matrix. In the biodegradability test in simulated soil and under UV radiation it was found that the presence of fiber, together with the coupling agent, did not prevent the degradation of the material, characterized by the presence of bands in the region of the carbonyl in the FTIR spectrum. However, morphological analysis was not observed crack formation, fissures and biofilm in the samples subjected to biodegradation in soil, however, at cracks were observed in the UV aging, this effect was less pronounced in the presence of coupling agent. In both trials of degradation was found that the presence of curaua fiber retards the degradation of the matrices when evaluated by measuring tensile strength. It was found that the recycling of EPS enables their use in obtaining vegetable fiber composite, reducing the environmental impact created disposal. Additionally it was proved that composite fiber curaua reinforced polystyrene has good properties and can be used as an engineering material.

Submitted in partial fulfilment of the requirements for the degree of Master of Arts in the Department of Psychology University of Zululand, 1984. / As indigenous healers are so important to the health of many not only in South Africa but also throughout the world, a closer, scientific look at their practices is needed. Again, there is a tendency of the majority of South Africans (especially the Blacks) to consult both western oriented mental health> services and indigenous healers. Various prominent mental health professionals in South Africa have appealed that greater recognition be given to and greater use made of the skills of indigenous healers in the treatment of persons who could benefit from the services- It is for these reasons that this research on indigenous healing was undertaken. The purpose of this research was to investigate diagnostic and treat¬ment methods used by a random sample of indigenous healers from the rural Mtunzini district in Kwa-Zulu, and to ascertain whether there is any consistency (inter-practitioner) in their diagnostic and treatment methods. Twelve practitioners were each invited by a researcher and a confederate with a problem requiring treatment. Diagnostic and treatment procedures were tape recorded. Standardized data regarding diagnosis, cause symptomatology, treatment and prognosis, including practitioners' biographical data was collected. In order to ascertain inter-practitioner consistency, practitioners were asked to rank order six diagnosis and six treatment procedures ascertained to be the most frequently occuring among all twelve practitioners. The results emphasized the three distinct basic categories of Zulu indigenous practitioners viz. doctors (izinyanga), diviners (jzangoma) and faith healers (abathantfazi). Of these categories, the diviner deserve special mention as the results consistently portrayed her as a superior specialist e.g. an elderly, educated, female preserver and provider of traditional Zulu culture. Diagnostic and treatment procedures used by the practitioners were found to be based on dualistic levels viz. natural and supernatural. As suggested by previous studies and also supported in this research, more integration of Western and African oriented mental health subsystems was recommended.

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