Diploma thesis deals with processing of two types of PP, HDPE, LDPE, PET, PA, PS, PMMA and ABS by reactive extrusion in presence of peroxides. The theoretical part summarizes existing knowledge about processing of used polymers. Reactive extrusion was carried out with a single screw extruder at 260 °C, 30 rpm and 60 rpm depending on peroxide used. One type of PP was processed in presence of Luperox 101, hydrogen peroxide, dicumyl peroxide and potassium persulfate. Luperox 101 and hydrogen peroxide were chosen for reactive extrusion of other polymers. The efficiency of selected peroxides on radical modifications of individual polymers during processing was evaluated by methods of rheological (MFI), structural (FTIR) and thermal (DSC) analysis.

Le projet vise à développer de nouvelles méthodologies exploitant le caractère intensif et éco-compatible de l'extrusion réactive appliquée à des polymères issus de la biomasse. Les polymères naturels possèdent des propriétés physico-chimiques à l'état natif qui limitent leur utilisation dans un grand nombre de secteurs industriels. Des modifications chimiques même limitées permettent de modifier radicalement les propriétés de ces objets macromoléculaires. Les modifications chimiques couramment effectuées en solution ou en batch posent des problèmes de mise en œuvre, de contrôle réactionnel, de coût énergétique et environnemental (coproduits, utilisation de réactifs posant problèmes). Le projet vise à étudier et mettre au point d'une part les paramètres de composition (polymères, plastifiants, réactifs...) et d'autre part les conditions opératoires de la modification chimique réalisée en extrudeuse : taux d'hydratation, pression et température. Trois familles des biopolymères d'intérêt pour les grandes filières des bioraffineries seront considérées, avec des réactions de modification spécifiques visant à répondre aux spécifications d'applications : amidon et maltodextrines, lignines et dérivés thermoplastiques de la cellulose / The project involves developing new chemical modifications methodologies using the ecologically compatible and intensive characteristics of reactive extrusion applied to polymers from biomass. With the prospect of worldwide exhaustion of oil supply, the use of renewable natural polymers as potential substitution candidates for oil based application polymers appears as a sustainable alternative. Natural polymers possess physicochemical properties in the native state, which limit their use in many industrial sectors. Even limited chemical modifications radically change the properties of these macromolecular entities. Chemical modifications commonly performed at industrial level in solution or in batches are often very laborious to implement, control, and in addition suffer from energy and environmental cost problems (co-products, use of reagents posing problems). The project aims at studying and developing the composition parameters (polymers, plasticizers, reagents ...), and secondly examining the operating conditions of the chemical modification carried out in an extruder: hydration rate, pressure and temperature kinetics and other parameters with reactions of specific modifications to meet the requirements of industrial applications. Three families of biopolymers of interest to large sectors of biorefineries will be considered: starch and maltodextrins, thermoplastic lignin and cellulosic derivatives.

L'objet de cette thèse a été le renforcement d'un copolyester thermoplastique par extrusion réactive au sein d'une extrudeuse bi-vis. L'objectif a été de faire réagir différents additifs avec les groupements réactifs du copolyester afin de créer et d'identifier de nouvelles structures moléculaires. Différentes stratégies ont été étudiées : l'ajout de polyetheramines de différentes masses molaires et différentes fonctionnalités, l'ajout de résines phénoliques dans différentes conditions, et le développement in situ lors de l'extrusion d'une phase thermodurcissable au sein de la matrice thermoplastique par des réactions époxy-amines / The goal of this thesis work was to reinforce a thermoplastic copolyester by reactive extrusion in a twin-screw extruder. The objective was to trigger chemical reactions between different additives and the reactive groups of the copolyester in order to create and identify new molecular structures. Several strategies were studied: the addition of polyetheramines presenting different molar masses and functionalities, the addition of phenolic resins in different conditions, and the in situ development during the extrusion process of a thermoset phase in the thermoplastic matrix by epoxide-amine reactions

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The primary objectives of this study were to develop an effective reactive extrusion process to produce granular phosphorylated pea starches with enhanced enzyme resistance, and examine the effects of bulk phosphorylation conditions on the morphology, physicochemical and functional properties of extruded pea starch phosphates. Two types of commercially available pea starches (NutriPea and Meelunie) were chosen as the research subjects in this study with differing native resistance. A number of methods including optical microscopy, SEM, ICP-OES, Englyst method, DSC and rapid visco analysis (RVA) were used to characterize the morphology and properties of extruded pea starches. The effects of feed formulations and extrusion conditions on phosphorus incorporation and Englyst digestion profiles were examined systemically. The results showed that phosphorus content and digestion profiles were highly dependent on the feed moisture. Enzyme resistance did not positively correlate with phosphorus content for extruded pea starch phosphates in contrast to their counterparts prepared by conventional aqueous slurry. This was because extrusion processing can markedly increase the susceptibility of pea starch granules to enzymatic digestion. Lower feed moisture content (40%) gave lower phosphorus content, significantly lower RDS content, and higher SDS and/or RS content. Bulk phosphorylation in the extruder resulted in decreased RS2 content but increased RS4 content. Screw geometry with excessive mixing index was not desirable in terms of producing resistant starch. High screw speeds (150rpm and 200rpm) and low feed rate (1.02kg/h) brought about higher yields of SDS and RS in spite of lower phosphorus incorporation. Reactive extrusion of pea starches under optimized conditions achieved a significant but moderate increase either in RS content (from 18.67% to 22.57% for NutriPea) or in SDS content (from 37.18% to 42.23% for Meelunie) compared to their native counterparts. However, RS and SDS content could not be improved simultaneously at least based on these pea starches and the reactive extrusion processes in this study. The optical and SEM micrographs confirmed that the granule integrity was largely retained after optimized reactive extrusion process. DSC thermograms found no significant correlation between gelatinization characteristics and Englyst digestion profiles. Evidenced by RVA pasting profiles, NutriPea pea starch phosphates exhibited enhanced thermal and shear stability in comparison to their native counterpart. A novel foaming injection technology of cross-linking reagents solution was pioneeringly introduced to uniformly coat all starch particles at the lowest moisture level possible during the continuous production of granular NutriPea pea starch phosphates. Yet, the resulting phosphorus incorporation was much lower than expected and would require further studies. / Thesis / Master of Applied Science (MASc) / The Canadian food industry is increasingly interested in the potential to probe new avenues to produce enzyme-resistant food starches from pulses starches. Although extrusion cooking is commonly used for manufacturing cereals, snacks and other food products, no research has been reported on using an extruder to rapidly produce resistant pulse starches for functional food ingredients. This study aimed to develop an effective reactive extrusion process to produce phosphate cross-linked pea starches with enhanced enzyme resistance (i.e., increased slowly digestible starch (SDS) and resistant starch (RS) content ) based on an examination of the effects of reaction conditions on the properties of extrusion products. Two types of commercially available pea starches, NutriPea and Meelunie, were chosen as subjects of the research. The cross-linked pea starches under optimized conditions achieved a significant but moderate increase either in RS content (for NutriPea) or in SDS content (for Meelunie) compared to their native counterparts. However, RS and SDS content could not be improved simultaneously at least based on these pea starches and the reactive extrusion processes in this study.

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Com a alta taxa de desertificação dos solos e a necessidade de irrigação constante dos plantios, existe a necessidade da criação de um polímero superabsorvente (SAP) com a característica de ser biodegradável. Observando o estágio tecnológico relacionado às atividades de pesquisa e desenvolvimento de SAPs no Brasil, foi utilizado o poli (álcool vinílico)/PVA e o amido de mandioca para a formação de hidrogéis a partir de blendas poliméricas. Assim, soluções aquosas desses polímeros foram reticuladas quimicamente, usando o glutaraldeído como agente reticulante e comparadas com amostras reticuladas por radiação gama, irradiadas a uma dose de 25 kgy. Os hidrogéis resultantes foram caracterizados por diversas técnicas analíticas como a fração gel, o intumescimento em água destilada, a espectroscopia de infravermelho com refletância total atenuada ATR (FT-IR), a termogravimetria (TG/DTG), a calorimetria exploratória diferencial (DSC) e a microscopia eletrônica de varredura (MEV). Observou-se uma maior reticulação nos hidrogéis reticulados com o glutaraldeído e em consequência um menor grau de intumescimento quando comparadas com as amostras que foram irradiadas. Com vias a produzir hidrogéis em uma escala industrial, misturas de PVA e amido foram processadas por extrusão reativa, mudando assim o processo de preparação de solução aquosa para misturas secas. Foram extrudadas amostras de PVA com diferentes pesos moleculares tais como o PVA 26-88, o PVA 40-88, o PVA 110-99 e o poli (ácido glioxílico vinílico)/PVGA, este último sintetizado a partir da modificação do PVA 110-99. Foi adicionado na mistura o ácido glioxílico no desenvolvimento do SAP por reticulação química nas amostras do PVA, por ter grupos carboxílicos que podem aumentar o intumescimento e também servir como agente reticulante. Também foram feitas formulações de extrusão sem o ácido glioxílico para serem usados como brancos. Adicionou-se nas misturas diversos agentes plastificantes como a glicerina e o polietilenoglicol (PEG 400) e as propriedades mecânicas foram estudadas. Foram desenvolvidas duas análises fatoriais de 23 para analisar as mudanças na reticulação das formulações. Os pellets foram caracterizados com as mesmas técnicas analíticas que os hidrogéis feitos em solução, adicionando-se análises de intumescimento e reversibilidade de intumescimento em diversos solventes como a água pura, a água da chuva, as soluções tampão de pH 3, pH 7 e pH 10, além de soro fisiológico, visando a aplicação em diferentes solos com diferentes pH e salinidades. Os testes de intumescimento em diferentes sais demonstraram a ter menor retenção de água quando comparada com água pura. Os testes de reversibilidade de intumescimento dos pellets mostraram que a maioria das formulações perde a sua capacidade de intumescimento máximo aos seis primeiros ciclos. Foi feita a compressão dos pellets para observar a flexibilidade dos mesmos, visando aplicações debaixo do solo. Realizou-se um estudo de biodegradação em terra ao longo de 120 dias, e estudou-se a relação direta com os valores da fração gel. Os resultados mostraram que os pellets menos reticulados intumesceram mais, enquanto as microscopias mostraram que essas amostras tinham uma morfologia mais porosa, o que contribuiu na melhora na retenção do líquido. Além disso, eram mais flexíveis e biodegradaram mais rápido, sendo extremamente viáveis para a aplicação na agricultura. Foi verificado que o PVA 40-88 apresentou os melhores valores de intumescimento em diferentes sais. Com o SAP obtido, foi constatado que a extrusão reativa é um método viável para a produção dos SAPs. / With high soil desertification rate and the need for constant irrigation of the plantations, there is the need to create a superabsorbent polymer (SAP) with the characteristic of being biodegradable. Noting the technological stage related to research and development activities of SAPs in Brazil, we used poly (vinyl alcohol)/PVA and cassava starch for the formation of hydrogels from polymer blends. Thus, aqueous solutions of these polymers were chemically crosslinked using glutaraldehyde as crosslinking agent and compared to samples cross-linked by gamma irradiation, irradiated the a dose of 25 kgy. The resulting hydrogels were characterized by various analytical techniques such as gel fraction, swelling in distilled water, infrared spectroscopy with attenuated total reflectance (ATR-FTIR), thermogravimetry (TG/DTG), the differential scanning calorimetry (DSC) and the scanning electron microscopy (SEM). There was a higher crosslink in the hydrogels crosslinked with glutaraldehyde and consequently a lower degree of swelling as compared to samples that were irradiated. With routes to produce hydrogels on an industrial scale, PVA and starch mixtures were processed by reactive extrusion, thus changing the aqueous solution preparation process to dry mix. PVA samples were extruded with different molecular weights such as PVA 26-88, PVA 40-88, PVA 110-99 and poly (vinyl glyoxylic acid)/PVGA, the latter synthesized from the modified PVA 110-99. It was added to the mixture glyoxylic acid in the SAP development by chemical crosslinking of the PVA sample for having carboxyl groups that may increase the swelling and also serve as crosslinker. Also extrusion formulations were made without the glyoxylic acid to be used as white. Was added to the mixture, various plasticizers such as glycerin and polyethylene glycol (PEG 400) and the mechanical properties were studied. two factor analyzes were developed from 23 to analyze the changes in crosslinking formulations. The pellets were characterized with the same analytical techniques that hydrogels made in solution by adding analyzes swelling and swelling of reversibility in various solvents such as pure water, rain water, pH buffer solutions 3, pH 7 and pH 10, in addition to saline solution, aimed at application in different soils with different salinities and pH. swelling tests at different salts shown to have lower water retention when compared to pure water. The pellets reversibility of the swelling tests showed that most formulations loses its swelling capacity up to the first six cycles. The compression of the pellets was taken to observe their flexibility, targeting applications underground. We conducted a study of biodegradation on land over 120 days, and studied the direct relationship with the gel fraction values. The results showed that the pellets swelled more crosslinked least while microscopy showed that these samples had a more porous morphology, which contributed to the improvement in fluid retention. Moreover, they are more flexible and biodegrade more rapidly and are extremely viable for use in agriculture. It has been found that PVA 40-88 showed better swelling values at different salts. With SAP obtained, it was found that the reactive extrusion is a viable method for the production of SAPs.

O amido termoplástico (TPS) é um material biodegradável, de baixo custo, com grande potencial para aplicação na composição de plásticos biodegradáveis. Muitos estudos têm sido realizados no sentido de melhorar algumas de suas propriedades, principalmente a sua baixa resistência mecânica, elevada hidrofilicidade, e baixa miscibilidade com polímeros comerciais, fatores que dificultam a ampliação da utilização desse material como plástico biodegradável. Uma alternativa para melhorar tais propriedades, é a produção de blendas destes materiais com outros polímeros. Contudo, quando a natureza química dos materiais a serem combinados é muito diversa, faz-se necessário compatibilizar os materiais, em geral obtida pela adição de agentes compatibilizantes ou promovendo reações durante a extrusão, processo denominado compatibilização reativa. No trabalho, diferentes alternativas foram investigadas com o intuito de aumentar o potencial de aplicação do amido, entre elas: o efeito do ácido cítrico na modificação do amido; o uso da ureia para estabilização da massa molar do amido via extrusão reativa permitindo seu reprocessamento; a modificação do amido com ácido cítrico e ou 4,4\'-difenil metano diisocianato e o uso de dois processos de extrusão reativa para produção do amido termoplástico; a produção de blendas de amido com poli(butileno adpato co-tereftalato) e poli(ácido lático); a produção do amido termoplástico com reticulação termorreversível pela incorporação de reações de Diels-Alder. Foram feitas diversas caracterizações entre elas, análise das propriedades térmicas por meio das técnicas de termogravimetria (TGA), calorimetria exploratória diferencial (DSC), análise dinâmicomecânica (DMA) ensaios mecânicos, absorção de umidade, espectroscopia de infravermelho por transformada de Fourier (FTIR), microscopia eletrônica de varredura (MEV), análises reológicas, cromatografia (HPSEC) e viscosimetria. Os resultados das investigações contribuíram para o desenvolvimento de novos polímeros termoplásticos ou termorrígidos a base de amido de milho e esclareceram questões não abordadas na literatura, sobre a modificação do amido via processo de extrusão reativa. / Thermoplastic starch (TPS) is a biodegradable material, inexpensive, with high potential of usage in the biodegradable plastics composition. Many studies have been performed to improve some properties, mainly its low mechanical strength, high hydrophilicity and low miscibility with commercial polymers, factors that hinder the usage expansion such material as plastic. An alternative to improve these properties is the polymer blends of starch production with other polymers. However, when the materials chemical nature is quite variable then is necessary to make the polymers compatible. Usually, the reactive compatibility is obtained by the addition of coupling agents or promoting reactions during extrusion. In the present study, new alternatives were studied in order to increase the starch application potential including: the citric acid effect on starch modification; use of urea to stabilize the starch molecular weight by reactive extrusion allowing its reprocessing; the starch modification with citric acid and 4,4\'-diphenyl methane diisocyanate and the use of two reactive extrusion processes for thermoplastic starch producing; starch blends production with poly (butylene adipate co-terephthalate) and poly (lactic acid); the starch modification by incorporating crosslinking thermoreversible Diels-Alder adduct. Several characterizations were made including thermal analysis by means of thermogravimetry (TGA), differential scanning calorimetry (DSC), dynamical mechanical analysis (DMA) mechanical testing, moisture absorption, Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), rheology analysis, chromatography (HPSEC) and viscometry. The research results have contributed to the development of new thermoplastic polymers or thermosetting from corn starch and helped to clarify issues not addressed in the literature about the starch modification by reactive extrusion process.