Des alliages nanostructurés, co-continus et thermodynamiquement stables sont synthétisés, par extrusion réactive d'un polyéthylène fonctionnalisé (FPE) et d'un mélange bimodal de petites et longues chaînes de polyamide 6 (PA). Les petites chaînes réagissent rapidement pour former beaucoup de copolymères, garantissant ainsi la nanostructuration. Le greffage et l'incorporation des longues chaînes a pour but d'introduire des enchevêtrements et des molécules liens entre les cristallites de PA. Deux extractions sélectives successives nous ont permis de caractériser les chaînes de copolymères greffés et les chaînes non-réagies de FPE et de PA. Les propriétés macroscopiques des alliages sont optimisées en jouant sur l'ordre d'introduction des constituants, les conditions d'extrusion et la composition de la phase de PA. L'étude structurale des alliages et des copolymères greffés précise l'organisation des chaînes dans les deux nanostructures. Les deux phases de FPE et PA cristallisent de manière confinée ce qui confère aux alliages des propriétés mécaniques remarquables. Aux faibles déformations et au dessus de la fusion du FPE, les alliages de composition 64/36 FPE/PA en masse, présentent une tenue thermomécanique d'une vingtaine de mégapascals. Les longues chaînes de PA jouent le rôle de chaînes liens entre les cristallites et améliorent la ductilité des alliages nanostructurés à haute température (allongement à la rupture 250% à 150°C). Des expériences de diffusion des rayons X couplées à de la microscopie électronique en transmission avant et après traction permettent de relier les évolutions structurales et morphologiques aux comportements mécaniques de ces alliages.

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This thesis reports a fundamental study on microwave assisted moulding (MAM), a novel technology where expandable starch based pellets made from extrusion are expanded within a mould cavity into blocks using microwave heating. Foamability or degree of expansion of starch-based pellets during microwave heating was studied comprehensively in terms of: the variation of raw natural materials, the extrusion conditions, the additives and the preconditioning of pellets before foaming. The expansion behaviour, foamed cell structures and mechanical properties of expanded pellets were characterized together with the characterization of microstructure of the extrudate materials and physical properties. Characteristics in microwave assisted moulding of the expandable pellets were then studied in terms of: the interfacial bonding and fusion between foamed pellets, the achievement of uniform heating through a moulded block, the loading of pellets and mould filling during foaming. It has been found that the degree of free expansion during microwave heating of the starch-based pellets is dependent on the degree of cook of starch during extrusion, the better the distructurization of the native starch granules, the higher the foamability in microwave heating. The maximum expansion ratio achieved in this work is 14, corresponding a foam porosity of 93%. Hydrophilic additives such as PYA and glycerol have adverse effect on the foamability due to combination effects of the melting point of the materials, degree of cook of starch in the pellets and water molecular mobility during foaming. Nucleation agents such as talc powder can refine cell structure of the foams and enhance elastic modulus, strength and energy absorption during compression. Addition of salts enhances microwave heating rate, expansion ratio and plasticization of the foam. Foamed blocks can be made using the MAM technology by adequate mould material, pre-treatment of the pellets, and control of initial loading in the mould cavity. This study paved the way for further development of the MAM technology for moulding of starch-based foams.

Nearly 60 m tonnes of waste is produced annually in Europe from “plastic packaging” engendering significant challenges for legislative controls and minimisation of environmental impact. There is an increasing demand for biodegradable packaging, which can be disposed of with minimum environmental impact, but the growing market is still in its infancy predominantly due to a lack of materials having environmental, practical and economic suitability. This research project dealt with some processing challenges of environmentally friendly packaging materials from renewable resources, as a long term solution to mitigate some issues associated with oil based plastic packaging. In this work, novel Polylactic acid (PLA) and starch based composites were developed with the requisite technical properties to fill the gap in the food packaging and cosmetic packaging industry. It was found that starch can be incorporated in a PLA matrix at the 10% level without difficulty in processing in the presence of 2% methyldiphenyl diisocyante. The blend shows properties similar to pure PLA. It was also found that the elongation at break and impact properties of PLA can be increased remarkably by the addition of a biostrength impact modifier. Furthermore, mixing of PLA and starch in the blend is efficient when the PLA particle size is reduced. It was also found that flexible and tougher PLA/starch blend pellets, that can be injection moulded, can be produced by an extrusion process with a range of additives. Each additive has a maximum level that exhibits optimum properties. The blends also established that 15% starch can be incorporated into the PLA matrix to reduce the cost without any processing difficulties. Encouragingly, the presence of an impact modifier in the PLA/starch blends has shown more desirable properties. Furthermore, the mechanical properties of the pellets exposed to increased residence time in the injection moulding barrel and of the test specimens stored for 9 months at 21ºC were also satisfactory for the new blend. The overall results exhibited some attractive properties in the tri blend system, which can be easily adopted by the plastics industry for development of an injection moulded product within the scope of applications such as dry food packaging or cosmetic packaging. A further finding of this project is that biodegradation under a home composting environment can be improved by incorporating starch and certain other modifiers into PLA.

Les mélanges de polymères ouvrent une importante voie à l’obtention de nouveaux matériaux dont les propriétés peuvent être très différentes de celles de chacun des constituants des mélanges. La plupart des polymères sont immiscibles. Ainsi leurs mélanges constituent des phases distinctes et les propriétés de ces mélanges sont souvent médiocres. Afin de relever ce défi, copolymères à bloc ou greffés synthétisés séparément ou générés in-situ lors du procédé de mélanges sont souvent utilisés en tant que agents compatibilisants. Beaucoup d’études ont porté sur l’efficacité de compatibilisation de copolymères à bloc et peu d’études sur celle de copolymères greffés, en partie en raison des difficultés dans le contrôle de leurs structures moléculaires. Cette thèse porte sur l’étude de l’efficacité d’émulsification de copolymères greffés. Elle est composée de trois parties : (1) développement d’un nouveau procédé d’extrusion réactive pour la synthèse de copolymères greffés avec polystyrène (PS) comme squelette et polyamide 6 (PA6) comme greffons ; (2) efficacité d’émulsification du copolymère greffé, PS-g-PA6 pour les mélanges à base de PS et PA6 ; et (3) développement d’un nouveau concept dit d’agent émulsifiant – traceur / Polymer blending offers an important route to new materials with combinations of properties not available in constituent polymers. Most polymer pairs are immiscible, leading to phase separation at equilibrium and yield a material with poor properties. To address this challenge, block or graft copolymers pre-made or generated in-situ by reactive blending are often used as compatibilizers. Most studies are focused on the compatibilizing efficiency of block copolymers and few studies address that of graft copolymers, partly because of difficulties of controlling their molecular structures.This thesis is devoted to the study of the emulsification efficiency of graft copolymers. It is composed of three parts: (1) development of a novel reactive extrusion process for synthesizing graft copolymers with polystyrene (PS) as backbone and polyamide 6 (PA6) as grafts; (2) emulsification efficiency of PS-g-PA6 graft copolymers for PS/PA6 blends; and (3) concept of emulsifier- tracer

<p>U disertaciji je elaborirana mogućnost primene relaksirajućih otvora kod istiskivanja delova sa ozubljenjem u cilju smanjenja parametara procesa. Primenjena su dva modela deformisanja, kada je otvor u pripremku i kada je otvor u žigu. Metodom gornje granice izvr&scaron;ena je teorijska analiza procesa i kreirano re&scaron;enje na osnovu koga su određeni deformaciona sila, pritisak na žig i promena geometrije dela. Pomoću eksperimenta istiskivanja i numeričke simulacije procesa izvr&scaron;ena je verifikacija teorijskog re&scaron;enja. Teorijski, eksperimentalni i rezultati simulacije procesa su pokazali da primena relaksirajućih otvora na analizirane tipove ozubljenja dovodi do smanjenja deformacione sile i pritiska u procesu.</p> / <p>Possibility of flow relief openings applying in cold extrusion of gear-like elements in order to reduce the process parameters is elaborated in this thesis. Two different deformation models are analysed: when the opening is in the billet and when the opening is in the punch. Upper bound method was applied for the process analysis and determination of deformation force, punch pressure and change of part geometry. Extrusion experiment and numerical simulation of process are used for verification of theoretical solution. Theoretical, experimental and numerical results confirmed that application of flow relief openings enables reduction of deformation force and punch pressure in the process of gear-like elements extrusion.</p>

<p>U radu je ispitana mogudnost kori&scaron;denja konzumnog suncokreta i suvog ostatka divljeg origana, kao funkcionalnih komponeti za dobijanje fleks proizvoda pobolj&scaron;anih nutritivnih svojstava.<br />Optimizacijom temperature su&scaron;enja (84&deg;C, 105&deg;C, 135&deg;C, 148&deg;C) fleks proizvoda utvrđen je uticaj temperature na: hemijske, fizičke i antioksidativne osobine fleks proizvoda. Na osnovu standardne ocene fleks proizvoda dobijenih na različitim temperaturama su&scaron;enja utvrđeno je da najvedu standardnu ocenu (0,91) ima fleks proizvod dobijen primenom temperature su&scaron;enja od 84&deg;C.<br />Ispitivanjem uticaja različitih količina konzumnog suncokreta (3%, 6% i 9%) i divljeg origana (0%, 0,5% i 1%) na fizičke karakteristike fleks proizvoda i utvrđeno je da dodatak konzumnog suncokreta ima negativan uticaj, a suvi ostatak divljeg origana pozitivan uticaj na nasipnu mase i stepen ekspanzije proizvoda. Uzorak bez konzumnog suncokreta i sa 1% origana ima najbolje fizičke karakteristike, minimalnu nasipna masu od 150,2 gml-1 i maksimalan stepen ekspanzije 9,36 mlg-1.<br />Dodatak konzumnog suncokreta uticao je na promene u masnokiselinskom sastavu proizvoda. Uzorci sa 9% konzumnog suncokreta imaju manji sadržaj palmitinske (C16:0) i linolenske (C18:3) kiseline za 15%, odnosno 60% u odnosu na uzorke bez dodatka suncokreta. U pomenutim uzorcima je povedan sadržaj stearinske (C18:0) za 15% i oleinske kiseline (C18:1) za 25%.<br />Dodatak funkcionalnih komponenti u sirovinski sastav fleks proizvoda povedava sadržaj fenola dva puta, pri čemu maksimalna sadržaj fenola 2,84 mg GAE/g s.e. ima uzorak sa 9% konzumnog suncokreta i 1% suvog ostatka divljeg origana. Pomenuti uzorak karakteri&scaron;e i maksimalna antiradikalska aktivnost ekstrakata izražena preko parametara 1/IC50 0,75 mg/ml i FRAP 1,57 &mu;g AAE/g s.e<br />Konzumni sincokret u sirovinskom sastavu fleks proizvoda je pobolj&scaron;ao iskori&scaron;denje, odnosno svarljivosti proteina i sadržaj esencijalnih mineralnih materija. Dodatkom 9% suncokreta i 1% divljeg origana dobijen je maksimalan sadržaj Zn 9,26 mg/kg, Cu 4,12 mg/kg, Mg 261,87 mg/kg i Fe 12,03 mg/kg.<br />Procesom ekstrudiranja, takođe, je do&scaron;lo do pobolj&scaron;anja mikrobiolo&scaron;kih parametaara kvaliteta proizvoda jer se značajno se smanjio ukupan broj mikroorganizama, broj kvasaca i plesni i mikroorganizama iz familije Enterobakteriaceae.<br />Na osnovu rezultata potro&scaron;ačkog testa za ispitvanje dopadljivosti proizvoda, utvr&scaron;eno je da dodatak suvog ostatka divljeg origana ima pozitivan efekat na op&scaron;tu prihvatljivost fleks proizvoda od strane potro&scaron;ača, dok dodatak konzumnog suncokreta negativno utiče na ukus, miris, osobine pri žvakanju i op&scaron;ta prihvatljivost.<br />Rezultati eksperimentalnog rada su pokazali da se dodatkom konzumnog suncokreta i suvog ostatka divljeg origana dobija fleks proizvod sa povedanom sadržajem funkcionalnih komponenata koji je dopadljiv potro&scaron;ačima.<br />Istraživanja u okviru ove disertacije su ukazala da bi funkcionalni fleks proizvod sa dodatkom divljeg origana i konzumnog suncokreta bolje prihvatili potro&scaron;ači stariji od 35 godina, visoko obrazovani i sa vedim primanjima. Međutim, i dalje je prisutan izvestan stepen nepoverenja potro&scaron;ača, pa je neophodno sprovoditi kontinuiranu edukaciju o zdravstvenim prednostima upotrebe funkcionalnih proizvoda u ishrani.</p> / <p>The paper examined the possibility of using consumable sunflower and dry extract of wild oregano, as functional components of obtaining a flex product of improved nutritional properties. By optimizing the drying temperature (84&deg;C, 105&deg;C, 135&deg;C, 148&deg;C) of the flex product, the effect of temperature was determined on: chemical, physical and antioxidant properties of flex products. On the basis of the standard assessment of flex products obtained at different drying temperatures it was determined that the highest standard rating (0.91) belongs to flex product prepared using the drying temperature of 84&deg;C.<br />By examining the influence of different amounts of consumable sunflower (3%, 6% and 9%) and wild oregano (0%, 0.5% and 1%) on the physical characteristics of flex products, it has been found that the addition of consumable sunflower has a negative impact, and a dry residue of wild oregano positive impact on the bulk weight and degree of expansion of the product. The sample free of consumable sunflower and with 1% of oregano has the best physical characteristics, minimal bulk weight of 150.2 gml-1 and a maximum degree of expansion of 9.36 mlg-1 .<br />The addition of consumable sunflower influenced the changes in fatty acid composition of the product. Samples with 9% of consumable sunflower have lower content of palmitic (C16:0) and 1inolenic (C18:3) acid by 15% and 60% compared to the samples without the addition of sunflower. In the above samples there was an increased content of stearic acid (C18: 0) by 15% and oleic acid (C18:1) by 25%.<br />The addition of functional components in the raw material composition of flex product increases phenol content twice, where the maximum phenol content of 2.84 mg GAE/g s.e. is found in the sample with 9% of consumable sunflower seed, and 1 % of dry extract of wild oregano. The aforementioned sample is characterized also by a maximum antiradical activity of extracts expressed via parameters 1/1C50 0.75 mg / ml and FRAP 1.57 ɲg AAE/g s.e.<br />Consumable sunflower in the raw material composition of flex products improved the utilization the digestibility of proteins and essential mineral substances content. By the addition of 9% of sunflower and 1% of wild oregano, we obtained the maximum content of Zn, 9.26 mg/kg, Cu 4.12 mg/kg, Mg 261.87 mg/kg and Fe 12.03 mg/kg. Extrusion process, also, led to an improvement in microbiological parameters of quality of the product because it significantly reduced the total number of microorganisms, yeasts and molds and microorganisms from the family of Enterobacteriaceae.<br />Based on the results of the test for examining consumer appeal of the product, it has been established that the addition of dry extract of wild oregano has a positive effect on the general acceptability of flex products by consumers, while the addition of consumable sunflower adversely affects the taste, the smell, the properties in chewing and general acceptability.<br />The results of the experimental work showed that the addition of consumable sunflower and dry extract of wild oregano resulted in the flex product with increased content of functional components that is appealing to consumers.<br />The research within this thesis pointed out that a functional flex product with the addition of wild oregano and consumable sunflower would be better accepted by consumers older than 35, highly educated and with higher incomes. However, there is still a certain degree of mistrust of consumers, so it is necessary to implement continuous education about the health benefits of the use of functional products in diet.</p>

Research into the processing conditions and parameters of polymeric nanocomposites has always been challenging to scientists and engineers alike. Many have developed tools and procedures to allow materials to be exploited and their properties improved with the addition of nanofillers to achieve the desired end material for various applications. Initial trials are mostly conducted using conventional small scale experiments using specialised equipment within the laboratory that can replicate the larger industrial equipment. This is a logical approach as it could save time and costs as many nanocomposites are relatively expensive to produce. Experiments have previously been done using the likes of the Haake twin screw extruder to manufacture nanocomposites within the laboratory but this research project has used a novel minimixer specifically developed to replicate mixing like large twin screw extrusion machines. The minimixer uses a twin paddle system for high shear mixing in conjunction with a single screw thus theoretically allowing an infinitely long recirculation. It is this ability to mix intensely whilst allowing for as long as desired recirculation which enables the replication in this very small mixer (10-30g capacity) of the mixing conditions in a large twin screw extruder. An added feature of the minimixer is that it can undertake inline data analysis in real time. The main experiments were conducted using a comprehensive DOE approach with several different factors being used including the temperature, screw speed, residence time, clay and compatibiliser loading and two polymer MFI's. The materials used included PP, Cloisite 20A, Polybond 3200, PET, Somasif MTE, Polyurethane 80A and Single / Multi-walled Carbon nanotubes. Detailed experimental results highlighted that rheological analysis of the nanocomposite materials as an initial testing tool were accurate in determining the Elastic and Loss modulus values together with the Creep and Recovery, Viscosity and Phase Angle properties in the molten state. This approach was also used in an additional set of experiments whereby the temperature, speed, residence time and compatibiliser were kept constant but the clay loading was increased in 1% wt. increments. These results showed that the G' & G'' values increased with clay loading. Another important finding was the bi-axial stretching step introduced after the processing stage of the nanocomposite materials which highlighted a further improvement in the modulus values using rheological testing. Other tests included using inline monitoring to look into both the viscosity and ultrasound measurements in real time of the molten polymer nanocomposite through a slit die attachment to the minimixer.

Cette thèse de doctorat spécialité « Chimie et Sciences des Matériaux » s'inscrit dans le pôle de compétitivité Chimie-Environnement Axelera, ainsi que dans le sous-programme de R&D Sepbatt SP.4.2. Duramat. Son objectif est d'élaborer la mise en place d'un protocole de fabrication par extrusion d'une membrane poreuse pour supercapacité. Cette membrane très fine joue un rôle très important dans le générateur électrochimique. Elle permet en effet, grâce à sa porosité, la circulation des ions entre les deux électrodes tout en évitant les courts-circuits, mais assure aussi les bonnes propriétés mécaniques du dispositif final. La volonté du fabricant de ces supercapacités est d'étudier la possibilité d'utiliser un nouveau moyen de fabrication de membranes séparatrices par le biais de mélanges de polymères fluorés / poly(oxyéthylène) et de la technique d'extrusion. L’incompatibilité des différents composants utilisés conduit à des mélanges hétérogènes révélant des structures multiphasiques présentant différentes morphologies. Il est alors important de caractériser et d'étudier l'évolution de ces morphologies et plus spécifiquement la morphologie co-continue. Différentes études ont ainsi été réalisées pour caractériser cette évolution. Les diagrammes de continuité des systèmes ont été déterminés grâce à la technique d'extraction sélective et confirmés par microscopie électronique à balayage alors qu'une étude rhéologique a permis de mettre en place une relation entre la morphologie et le comportement en fondu des différents systèmes utilisés. Le projet est ensuite finalisé grâce aux caractérisations physico-chimiques des membranes poreuses extrudées / This thesis specialized in "Chemistry and Materials Science" is part of the international cluster Axelera “Chemistry and Environment”, and in the R&D program Sepbatt SP.4.2.Duramat. Its aim is to develop a protocol for extrusion manufacturing of a porous membrane for double layers capacitor. This thin membrane plays a very important role in the electrochemical cell. It makes possible, thanks to its porosity, the flow of ions between two electrodes while avoiding short circuit, but also provides good mechanical properties of the final device. The desire of the manufacturer of double layers capacitor is to study the possibility of using a new method of separating membranes manufacturing, using mixtures of fluorinated polymers / polyethylene oxide and the extrusion technique. The incompatibility of the various components used leads to heterogeneous mixtures revealing multiphasic structures with different morphologies. It is then important to characterize and study the evolution of these morphologies and specifically co-continuous morphology. Various studies have been carried out to characterize this evolution. The continuity diagrams of the systems were determined using the technique of selective extraction and confirmed by scanning electron microscopy, while a rheological study allowed to establish a relationship between the morphology and behavior in the melt of the different systems used. The project is then completed through the physico-chemical characterization of porous membranes extruded

Doctor of Philosophy / Department of Animal Sciences and Industry / James S. Drouillard / A series of studies were conducted to evaluate extrusion processing of finishing diets on growth performance, carcass characteristics, and meat quality attributes of feedlot cattle. Extruded diets were processed in a 24:1 (length/diameter) corotating, fully intermeshing twinscrew extruder (model BCTG-62, Bühler AG CH-9240, Uzwil, Switzerland). In Experiment 1, extrusion processing of corn based diets decreased dry matter intake (DMI) and improved gain efficiency (G:F) by 15% compared to heifers fed steam-flaked corn (SFC) diets. Carcass characteristics were not different between treatments. Steaks from heifers fed SFC diets were juicier and had a less pronounced off-flavor than steaks from heifers fed extruded diets. In Experiment 2, average daily gain (ADG), DMI, G:F, carcass characteristics, and meat quality attributes were not different between heifers fed SFC and extruded processed corn diets. In Experiment 3, we evaluated different degrees of extrusion processing by altering the level of process water added to the extruder. Mechanical energy inputs, die pressure, die temperature, and torque of drive motor decreased as the level of water added to the extruder increased from 4% to 12%. Water addition did not affect DMI or ADG of feedlot heifers. However, live body weight (BW) and G:F decreased as the level of process water increased. Gain efficiency (carcass-adjusted basis) was 3% greater for extruded corn diets processed with 4% water compared with SFC diets and was 6% poorer than SFC diets when processed with 12% water. Apparent total tract digestibility was not different, but IVDMD improved with increasing levels of water. Improvements in G:F when fed extruded feed was variable among the 3 studies. This may be due, in part to severe infestation by European Starlings during Experiment 1. Impact of feed depredation by starlings was therefore evaluated. Starlings consumed 86% of the SFC diet offered to them compared to, none of the extruded corn diets. In addition, starlings preferentially selected for the energy dense portion of the rations (steam-flaked corn). Therefore, it is plausible that a portion of the 15% improvement in G:F observed in Experiment 1 for heifers fed extruded corn diets can be attributed to differences in feed depredation by starlings. Finally, two studies were conducted to evaluate extrusion processing of sorghum-based diets. In the first experiment, DMI was greater and G:F was poorer for heifers fed extruded sorghum diets compared to heifers fed steam-flaked sorghum (SFS) diets. However, carcass characteristics and meat quality attributes were not different. In the second study, particle size of the ground sorghum added to the extruder was evaluated. Processing sorghum to a smaller particle size (581 μm) prior to extrusion processing decreased DMI, improved G:F, and increased apparent total tract digestibility compared with larger particle sizes (1,264 μm). However, heifers fed SFS diets were still more efficient that heifers fed extruded diets made with either particle size of sorghum. Overall, this research suggests that extruding complete diets into homogeneous pellets may improve G:F of cattle fed corn-based diets while reducing feed depredation of starlings. It is also clear from our results that G:F is improved to a greater extent to processing diets under high shear conditions (i.e., high mechanical energy inputs) than when processed under low shear conditions.