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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Reducing the Water Absorption of Thermoplastic Starch Processed by Extrusion

Oakley, Philip 13 January 2011 (has links)
Novel plastics that are biodegradable and made from renewable natural resources are currently being researched as alternatives to traditional petroleum-based plastics. One such plastic, thermoplastic starch (TPS) is produced from starch processed at high temperatures in the presence of plasticizers, such as water and glycerol. However, because of its hydrophilic nature, TPS exhibits poor mechanical properties when exposed to environmental conditions, such as rain or humidity. The overall objective of this thesis was to produce a thermoplastic starch based material with low water absorption that may be used to replace petroleum-based plastics. Three different methods for reducing water absorption were investigated, including the following: extrusion of starch with hydrophobic polymers, starch modifying chemicals, and citric acid/sorbitol as plasticizers. It was found that all methods reduced the water absorption of TPS.
2

Reducing the Water Absorption of Thermoplastic Starch Processed by Extrusion

Oakley, Philip 13 January 2011 (has links)
Novel plastics that are biodegradable and made from renewable natural resources are currently being researched as alternatives to traditional petroleum-based plastics. One such plastic, thermoplastic starch (TPS) is produced from starch processed at high temperatures in the presence of plasticizers, such as water and glycerol. However, because of its hydrophilic nature, TPS exhibits poor mechanical properties when exposed to environmental conditions, such as rain or humidity. The overall objective of this thesis was to produce a thermoplastic starch based material with low water absorption that may be used to replace petroleum-based plastics. Three different methods for reducing water absorption were investigated, including the following: extrusion of starch with hydrophobic polymers, starch modifying chemicals, and citric acid/sorbitol as plasticizers. It was found that all methods reduced the water absorption of TPS.
3

Produktion av bioplast i Värmland? : Fermentering av olika avfallströmmar / Production of bioplastic in Värmland? : Fermentation of different waste streams

Sundin, Anton January 2015 (has links)
Ett av världens största miljöproblem är plastnedskräpning. På många platser kan spår av mänsklig närvaro ses i form av skräp av plast. År 2011 tillverkades det 280 miljoner ton plast, det motsvarar ungefär 28 000 Eiffeltorn. I Sverige förbrukades år 2010 ungefär 880 000 ton plast. I Asien produceras ungefär 50 % av all världens plast och Kina står för cirka hälften av detta. Nordamerika och Europa står för cirka 40 % av världens plastproduktion. Resterande produktion av plast är fördelat på Afrika och Sydamerika. Kommersiell plast är uppbyggd av små enheter kallade polymerer. Polymerer är i sin tur uppbyggda av ännu mindre enheter som kallas monomerer. Dessa monomerer är i dagsläget framställda av petroleum (råolja/mineralolja). Ungefär 4 % av världens oljekonsumtion går åt som råvara till att producera plast och lika mycket olja används som bränsle i tillverkningsprocessen. Begreppet bioplast är en hel familj av material som är biologiskt nedbrytbar, biobaserade eller bådadera. Det är dock inte en självklarhet att bioplaster besitter båda egenskaperna. PHA-plast är biobaserad och biologisk nedbrytbar, vilket är anledningen till att den står i fokus under detta examensarbete. För produktion av PHA-plast används en trestegsprocess, vilket innefattar ett fermenteringssteg, ett selektionssteg och ett ackumuleringssteg. Sist sker en extraktion för att frigöra PHA- plasten från det övriga organiska materialet. Syftet med det här examensarbetet är att med hjälp av framställning av bioplast främja miljön, vilket en anläggning som producerar bioplast skulle göra eftersom en del av den fossiloljebaserade plasten skulle kunna bytas ut mot bioplasten PHA. Större framställningsmöjligheter av bioplast i Värmland skulle medföra ett ökat intresse av en produktionsanläggning. Målet är att inventera olika industrier runt om i Värmland, i första hand matindustrier och skogsindustrier, och utreda deras processavloppsvattens potential att producera VFA. I detta examensarbete har fermenteringsförsök genomförts satsvis på processavloppsvatten från OLW, Barilla (Wasa), Skoghall, Gruvön och Rottneros. Försöken visar deras potential att producera VFA. Experimenten utfördes med ett konstant pH på 6 och varierande uppehållstid. Resultaten visade att OLW och Barilla har bäst potential till VFA-produktion med 4500 mg/l respektive 1610 mg/l. Spädning av OLWs och Barillas processavloppsvatten visade sig vara en gynnsam åtgärd, då VFA-produktionen ökade snabbare i jämförelse med de tester som utfördes vid icke-spädning. Dock erhölls inte lika stor totalmängd av VFA. Det är dock bättre att producera en större mängd VFA och på så vis låta processen ta längre tid. Vid fortsatta experiment rekommenderas att göra ytterligare försök på OLW och Barillas processavloppsvatten då de visade bäst potential till VFA-produktion. / One of the biggest environmental problems is the plastic littering. In many places traces of human presence is seen in the form of plastic littering. In the year 2011, 280 million tons of plastic was produced, which represents about 28 000 Eiffel Towers. In Sweden, about 880 000 tons of plastic a year is consumed, according to figures from 2010. Approximately 50 % of all the world's plastics are produced In Asia and China accounts for about half of it. North America and Europe account for about 40% of the world's plastic production. The remaining production is distributed between Africa and South America. Commercial plastic is made from small units called polymers. A polymer consists of smaller units called monomers. In present, these monomers are produced out of petroleum (crude oil/ mineral oil). Approximately 4% of the world’s oil consumption is spent as raw material to produce plastic and the same amount of oil is used as fuel in the plastic production process. The term bio-plastic is used for a family of materials which are biodegradable, bio- based or both. However, it is not given that bioplastics do possess both properties. PHA plastics are both bio based and biodegradable, which is why it is the focus for this thesis. Production of PHA plastic is a three-step process comprising a fermentation step, a selection step, and an accumulation stage. Finally, there is an extraction to release the PHA plastic from the organic material. The aim of this thesis is to aid the production of bioplastics in order to lessen the environmental load of plastics. The more bioplastic that can be produced, the greater the interest of a bioplastic-producing plant in Värmland. The goal is to make an inventory of industries around Värmland, primarily food industries and forest industries, and to quantify the potential of their process wastewaters to produce VFA. In this thesis, fermentation experiments conducted batch-wise was performed with process wastewater from OLW, Barilla (Wasa), Skoghall, Gruvön and Rottneros. The experiments showed the wastewaters potential to produce VFA. The experiments were performed with a constant pH of 6 and with varying residence time. The results showed that OLW and Barilla has the highest potential for VFA production with 4500 mg/l and 1610 mg/l, respectively. Dilution of OLWs and Barillas process water turned out to be favorable, as the VFA production increased rapidly in comparison with those tests that were conducted under non-dilution. The total production of VFA, however, was not as high. In further experiments, it is recommended to make another attempt at the OLWs and Barillas process wastewater since they showed the best potential for VFA production.
4

Novel bio-composites based on whole utilisation of wheat straw

Zhao, Lei January 2013 (has links)
This thesis reports research work in the development of biocomposites based on whole utilisation of renewable wheat straw for industrial applications. The concept of “whole utilisation” is based on a previous work on a novel twin-screw extrusion technology for processing of feedstock in wheat straw reinforced bio-composites. It demonstrated that straw raw material could be restructurised into a feedstock with cellulose fibre finely dispersed in the non-cellulose matrix, which can be utilised as a bonding phase without having to be removed as in conventional processes to extract the cellulose. The whole straw can thus be utilised to avoid waste of materials and the negative impacts to environment associated with the extraction process. Raw wheat straw in this research was prepared in three ways: size reduction through mechanical milling, pre-treatment by aqueous NaOH solution and deep preparation with aqueous NaOH solution soaking followed by extrusion fractionation. Prepared wheat straws were processed into varieties of forms according to the applications. They were hot-compressed into self-reinforced composite with good flow ability and also processed through extrusion and compression moulding to compound with other biopolymers as good filler. The relationships of processing parameter and property, as well as formulation and property were established for each form of product, which provides a key understanding of the whole development circle of an end product. Through this research, scientific and technical problems has been addressed in materials formulation/processing, product design/manufacturing, enhancement of functionality/ performance as well as economical/environmental assessment so as to develop a series of cost-effective bio-composites and products, which satisfy diverse technical and environmental performance requirements in the industrial sectors across packaging, horticulture, building/construction and shooting sports.
5

A relação da comunicação e as embalagens biodegradáveis: um paradigma para a destinação final / The relationship of communication and biodegradable packaging: a paradigm for final disposal

Ottoni, Breno Luiz [UNESP] 01 July 2016 (has links)
Submitted by BRENO LUIZ OTTONI null (breno@bauru.unesp.br) on 2016-08-23T15:37:35Z No. of bitstreams: 1 Dissertação_final_OTTONI_BRENO_repositorio_unesp.pdf: 3950347 bytes, checksum: 2f3574a90c11f0c3e2baed2bb67eefde (MD5) / Approved for entry into archive by Juliano Benedito Ferreira (julianoferreira@reitoria.unesp.br) on 2016-08-26T14:33:38Z (GMT) No. of bitstreams: 1 ottoni_bl_me_bauru.pdf: 3950347 bytes, checksum: 2f3574a90c11f0c3e2baed2bb67eefde (MD5) / Made available in DSpace on 2016-08-26T14:33:38Z (GMT). No. of bitstreams: 1 ottoni_bl_me_bauru.pdf: 3950347 bytes, checksum: 2f3574a90c11f0c3e2baed2bb67eefde (MD5) Previous issue date: 2016-07-01 / É estimado que a geração de resíduos sólidos passará de 1,3 bilhão para 2,2 bilhões de toneladas até 2025, ocasionando problemas ambientais, sociais e, consequentemente, à saúde pública. A maior problemática neste aspecto envolve o destino inadequado dos resíduos, e no Brasil ainda se destina pouco resíduos à triagem para reciclagem ou compostagem. Neste cenário, as embalagens plásticas oriundas de fonte não renovável de energia possuem baixas taxas de reciclagem. Desta forma, surgem os bioplásticos como alternativa, por serem em sua maioria biodegradáveis. Este estudo visa discutir os aspectos comunicacionais relacionados diretamente às embalagens de bioplásticos e apresentar como a função comunicação nas embalagens podem contribuir para fornecer informações relevantes aos consumidores, a fim de minimizar o problema da destinação inadequada. Utilizou-se a pesquisa qualitativa como método a alcançar os objetivos propostos. Conclui-se que a comunicação, seja nas embalagens de plástico ou bioplástico, deve promover as ações nas pessoas: a não geração, a redução, a reutilização e a reciclagem de resíduos sólidos, gerando, desta forma, um ciclo de solução nas problemáticas abordadas neste estudo. / It is estimated that the solid waste generation will grow from 1.3 billion to 2.2 billion tons by 2025, causing environmental and social problems and therefore, to public health.The biggest problem on this aspect involves the inappropriate disposal of waste and Brazil still intended for little waste sorting for recycling or composting. In this scenario, the plastic packaging from non-renewable energy source have low recycling rates. Thus, bioplastics come as an alternative because they are biodegradable in their majority. This study aims to discuss the communication aspects directly related to bioplastics packaging and presenting how communication function in packaging can help to providing relevant information to consumers in order to minimize the problem of improper disposal. The qualitative research was used as a method to achieve the proposed objectives. It can be concluded that communication, whether in plastic or bioplastic shall promote the actions on people about not generation, reduction, reuse and recycling of solid waste, thus creating a solution cycle on the addressed problems in this study.
6

Desenvolvimento e caracterização de bioplástico obtido a partir do amido residual proveniente da industrialização de batata frita /

Romeira, Karoline Mansano January 2019 (has links)
Orientador: Rondinelli Donizetti Herculano / Resumo: Durante o processamento industrial das batatas fritas há a produção de uma grande quantidade de amido residual proveniente da lavagem da matéria prima. Os biopolímeros, tipo amido, têm sido propostos para formulação de materiais biodegradáveis. A aplicação do amido na produção de bioplástico se baseia nas propriedades químicas, físicas e funcionais para formar géis e filmes. O objetivo desse estudo foi desenvolver bioplásticos elaborados a partir de amido residual, utilizando diferentes proporções de amido residual e glicerol combinado com alginato e com ácido acético; caracterizar os materiais obtidos quanto à composição e características das ligações formadas, contaminação microbiológica, propriedades mecânicas e características de barreira; e aplicar o bioplástico, utilizando o método de imersão, em frutos de mamão (Carica papaya), avaliando qualitativamente os resultados obtidos. Os resultados apresentados expressam que as soluções filmogênicas produzidas a partir de amido são viáveis para a obtenção de filmes, sendo possível fabricar bioplásticos com as duas composições propostas. As análises de viabilidade microbiológicas e as análises de cromatografia gasosa apontaram que os bioplásticos, em ambas composições, se tornam microbiologicamente estáveis e ausentes de solventes controlados, como o toluol. No FTIR observou-se que ligações de hidrogênio foram formadas em ambas as amostras e essas ligações de hidrogênio conferiram as amostras diferentes características mecânica... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: During industrial processing of potato, a large amount of residual starch is produced from the washing of the raw material. Starch-like biopolymers have been proposed for formulation of biodegradable materials. The application of starch in bioplastic production is based on chemical, physical and functional properties to form gels and films. The aim of this study was to develop bioplastics made from residual starch using different proportions of residual starch and glycerol combined with alginate and acetic acid; characterize the materials obtained for the composition and characteristics of the formed bonds, microbiological stability, mechanical properties and barrier characteristics; and to apply the bioplastic, using the immersion method, in papaya fruits (Carica papaya), qualitatively evaluating the obtained results. The presented results express that the filmogenic solutions produced from starch are viable to obtain films, being possible to manufacture bioplastics with the two proposed compositions. Microbiological viability analyzes and gas chromatography analyzes indicated that bioplastics in both compositions become microbiologically stable and absent from controlled solvents such as toluol. In the FTIR it was observed that hydrogen bonds were formed in both samples and these hydrogen bonds gave the samples different mechanical characteristics. The higher the starch: glycerol ratio, the greater the elongation of the sample in the stress versus strain test, and the more ... (Complete abstract click electronic access below) / Mestre
7

STUDIES ON THE REACTIVE BLENDING OF POLY(LACTIC ACID) AND ACRYLONITRILE BUTADIENE STYRENE RUBBER

Vadori, Ryan 11 January 2013 (has links)
The polymer materials industry is heavily dependent on the use of petroleum based plastics. This poses a problem, as the world is facing ongoing petroleum supply problems. A need exists for a bio-carbon based polymer material that has the performance and cost of currently used petroleum plastics. However, the overall performance of current bio-based plastics indicate that they must be somehow supplemented to achieve the properties of that of petroleum-based polymers. The low impact strength and thermal stability of poly(lactic acid), PLA are targets for improvement. One option is for development is through blending with acrylonitrile butadiene styrene (ABS). The viability and efficacy of using these two polymers as blending partners is investigated. The PLA used in these studies has unique and interesting crystallization properties. These have been examined and detailed in part 1. The second part of study includes neat polymer properties, miscibility analysis, and large scale process results. This results in an optimized blending ratio on which to go forward with development. The mechanical, thermal, and morphological properties are investigated in these studies. Significance of this research and development is widespread, as the material developed has the potential to reduce the use of petroleum-based carbon in plastics. / The financial support from the 2010 Ontario Ministry of Agriculture, Food and Rural Affairs (OMAFRA)/University of Guelph -Bioeconomy for Industrial Uses Research Program, Natural Sciences and Engineering Research Council (NSERC) AUTO21 NCE project and Grain Farmers of Ontario (GFO), to carry out this research is gratefully acknowledged.
8

Toward libraries for increased bio plastic production in cyanobacteria / Metagenomiska bibliotek att förbättra cyanobakterier bioplast produktion

Muppidi, Mahanand January 2014 (has links)
Cyanobateria are promising cell factories due to their minimal nutrient requirements and utilization of asmospheric carbon di-oxide as its sole carbon source. In particular, polyhydroxybutyrate (PHB) is an industrially useful bio plastic that is produced naturally by some cyanobacteria. Furthermore, PHB biosynthetic pathway is a starting point for production of the biofuel, 1-butanol. There has been much genetic engineering effort toward increasing the production of PHB from cyanobacteria. These have been focused on increasing the pool of acetyl-CoA precursor, or increasing the amount of the reductant NADPH. The upstream process for increasing these reactants is complex and involves many genes. In this contect, cyanobacteria libraries will contribute to reveal genes or gene fragments that are responsible for production of PHB, alkanes and other high value compounds. In pursuit of finding these novel genes or genefragments, a transcription factor library is created in this study with 50 transcription factors. Furthermore, the process is optimized towards the creation of genomic fragment library and metagenomic fragment library with 26 diverse strains. Membersof the transcription factor library are over-expressed by a PHB - producing host Synechocystis PCC 6803 and the process towards creation of genomic and metagenomic libraries is optimized. The members of the metagenomic library can be screened for increased PHB, alkanes, lactate and other high value products and the potential members can be isolated and characterized.
9

Topological (Bio)Timber: An Algorithm and Data Approach to 3d Printing a Bioplastic and Wood Architecture

Macias, Diego 29 September 2017 (has links)
No description available.
10

Bioplastics from food waste liquid fraction / Bioplast från flytande delen av matavfall

Sundäng Peters, Emil January 2017 (has links)
No description available.

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