Statistic data indicates that about 100,000 tones of waste tire were generated each year. Current recycling market of waste tire is very small. Therefore, many waste tires remain untreated and cause severe health and safety problems in storage. PP fiber cut end is the waste material after cutting off the fiber. Traditional reuse way was to be the toy¡¦s fillers. If we can reuse the materials properly to develop a market of additional value, it will be a big contribution to the society. In this research, recycled waste tire powder and PP fiber cut end are used as oil adsorbents for the purpose of oil recovery during the process of oil spill emergency response. PP fiber cut end and waste tire powder are capable of adsorbing oil due to their hydrophobic surface property and the capillary forces developed during the contact with oil, therefore, makes them a perfect material for oil recovery. The major advantage of recycled PP fiber cut end is its high oil adsorbing capacity (approximately 48.4g/g). But, after reuse, its oil adsorbing speed was slow down, so does the oil adsorbing capacity. On the other hand, with good elasticity, the waste tire powder can be reused for more than 100 times without loosing its capability. However, the oil adsorbing capacity of waste tire powder is far less than PP fiber (approximately 2.84g/g). Finally, we combine PP fiber cut end and waste tire powder, to see if we can take the advantage of each product and make the best utilization of the composite material. Results indicate the composite material can be reused for more than 100 times without loosing its capability, and its performance is even better than the combination of each individual product. In the other test, we can see the composite material can not only adsorb engine oil and crude oil, but also adsorb emulsified oil. In the test, the composite material can recover up to 28 times of its own weight of oil. With the invented set up, the oil recover work is much easier to operate, and moreover, the composite material is less expensive. Only a squeeze roller and a collection container are required to recover oil. So, the composite material is indeed having practicability and mobility. Finally, the composite material is an excellent adsorbent compares with other products available on the market.

Silicones elastomers are widely used all over the world due to their unusual properties when compared to their carbon-based counterparts. Synthetic methods for their synthesis are still quite limited and the traditional silicone products are not able to completely meet the requirement for modern materials. Silicone elastomers with customized structures and with higher levels of sustainability will be the research focus for the development of next generation materials. The element sulfur and its functional groups are growing players in modern polymer and materials science, since sulfur reactions are exceptionally versatile. The incorporation of sulfur reactions into the design and preparation of silicone materials can lead to silicones with unique properties for various research interests. Initial exploration was focused on the creation of general and simple methods for 3D printing silicone elastomers using thiol-ene chemistry. However, silicone inks suitable for 3D printing are still quite limited. Photo-initiated thiol-ene chemistry was proposed to design a rapid cure silicone ink for extrusion 3D printing. Unlike other radical reactions, the relatively oxygen insensitive thiol-ene was able to provide the necessary rapid reaction rate and build up the necessary viscosity for practical printing in less than 2 seconds in the presence of air. Various customized silicone structures with different moduli were obtained with a relative fast printing speed. The use of thiol oxidation reactions in the synthesis of silicone elastomers is also demonstrated in this thesis. Reductive cleavage of the resulting disulfide bridge was successfully performed with the presence of hydrosilane and B(C6F5)3 catalyst. Herein, a synthetic method to reversible silicone elastomers based on the disulfide linkage is described. This method could be extended to cleave the disulfide and polysulfide linkage in used automotive rubber materials. Various kinds of sulfur-cured rubbers were successfully devulcanized to polymeric oil. This simple and efficient method could potentially offer a solution for the huge amount of tire waste produced every year. Finally, a new method for preparing thermoplastic silicone elastomers with ionic linkages is reported. A novel dicarboxylic acid-modified silicone was synthesized though thiol-Michael additions. The resulting ionic crosslinked networks were built though the neutralization between carboxylic and amino silicone. Thermoplastic silicone elastomers with unique viscoelastic behavior can be obtained. In summary, the thesis demonstrates that sulfur chemistry is an exceptional synthetic tool for the silicone chemist. / Thesis / Doctor of Philosophy (PhD)

Made available in DSpace on 2016-03-15T19:36:46Z (GMT). No. of bitstreams: 1 Caroline Valadao Pacheco.pdf: 1512199 bytes, checksum: 176990123a20dd9d8044075c1fca3be5 (MD5) Previous issue date: 2014-11-28 / This essay aimed to conduct a study on the rubber blanket of manufacture from waste tires. The disposal of tires has created an environmental problem, since the nature takes years to decompose them. On the other hand, the waste tire can be used on laminate flooring bases because this material has characteristics that can reduce noises that cause discomfort for the residents of buildings. This essay presents a study on the manufacture of rubber blanket using up waste tires with the purpose of reducing noise for the residents of buildings. This research becomes important both for society and for professionals and companies in general, because through it, they will have the knowledge not only about the materials, techniques and conventional processes, but they will also have a focus on how this issue of noise can be softened through materials that are often thrown on the street, polluting cities. The 50% of waste tire blanket obtained an absorption required by the regulation. The thickness of the blanket did not affect the internal height of apartment projects, because the thickness of the blanket is smaller than the expected subfloor. / Este trabalho teve o objetivo realizar um estudo sobre a fabricação de manta de borracha a partir de resíduos de pneus. O descarte de pneus tem gerado um problema ambiental, uma vez que a natureza leva anos para decompô-los. Por outro lado, os resíduos de pneus podem ser utilizados em bases de pisos laminados. Pois este material apresenta propriedades que podem diminuir os ruídos que causam tanto desconfortos para os moradores de prédios. Este Trabalho apresenta um estudo sobre a fabricação de manta de borracha utilizando-se resíduos de pneus com o propósito de diminuir incômodos para os moradores de prédios. Destaca-se que esta pesquisa torna-se importante tanto para a sociedade como para profissionais e empresas no geral, pois através da mesma, estes tomarão conhecimento não só dos materiais, técnicas e processos convencionais, mas também terão um enfoque de como esta problemática do ruído pode ser amenizada através de materiais que muitas vezes estão jogados na rua, poluindo as cidades. Para a manta com 50% de resíduos de pneu obteve-se a absorção exigida pela norma. A espessura da manta não interferiu no pé direito dos projetos de apartamentos, pois a espessura da manta é menor que a do contra piso previsto.