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Termoplaster används i en mängd olika produkter världen över. En starkare termoplast kan leda till att en mindre mängd material behövs för att bibehålla samma styrka i en produkt. En lättare produkt kan exempelvis leda till minskad bränsleförbrukning vilket är positivt i avseende för miljön, socialt och ekonomiskt.  Ett möjligt sätt att tillverka en starkare termoplast skulle kunna vara att förstärka den med cellulosafibrer. FineCell Sweden AB tillverkar cellulosafibrer i mikrostorlek genom en miljövänlig och energieffektiv kemisk process, vilket resulterar i en ekologiskt hållbar produkt. Nya tillverkningsmetoder som additiv tillverkning tillåter nya möjligheter för de former som kan tillverkas med termoplaster. Det är intressant att undersöka om det går att använda en cellulosaförstärkt termoplast till 3D-printning. Detta examensarbete har fokuserat på extrudering av mikrocellulosaförstärkt filament, och hur olika tillverkningsprocesser påverkar kvalitén och hur de mekaniska egenskaperna påverkas. Resultatet visar att mikrocellulosan i vissa fall kan ge ökad elasticitetsmodul, och att torkning och hantering av cellulosan innan extrudering är avgörande för egenskaperna, då eventuell fukt leder till porer vilka påverkar de mekaniska egenskaperna negativt.  I vidare arbete skulle fler materialegenskaper för det tillverkade filament vara intressant att undersöka. Det skulle vara intressant att tillverka filament med en ”Twin-screw” extruder, då det kan fördela fibrerna och skjuva till mindre storlek. Det skulle även vara intressant att undersöka mikrocellulosaförstärkning med andra typer av tillverkningsmetoder, högre fiberandelar och andra sorters termoplaster. / Thermoplastics are used in a variety of products worldwide. A stronger thermoplastic could lead to a smaller amount being needed to maintain the same strength in a product. A lighter product can, for example, lead to reduced fuel consumption, which is positive for the environment, socially and economically. One possible way to make a stronger thermoplastic could be to reinforce it with cellulose fibers. FineCell Sweden AB manufactures micro-sized cellulose fibers through an environmentally friendly and energy-efficient chemical process, which results in an ecologically sustainable product. New manufacturing methods such as additive manufacturing allows new possibilities for the shapes that can be manufactured with thermoplastics. It is interesting to investigate whether it is possible to use a cellulose-reinforced thermoplastic for 3D-printing. This master thesis has focused on the extrusion of microcellulose-reinforced filament and how different manufacturing methods affect the quality and how the mechanical properties are affected. The results show that the microcellulose can in some cases give an increased modulus of elasticity and that drying and handling of the cellulose before extrusion is decisive for the properties, as any moisture leads to pores which adversely affect the mechanical properties. In further work, more material properties of the manufactured filament would be interesting to investigate. It would be interesting to make filaments with a "twin-screw" extruder, as it can distribute the fibers and shear to a smaller size. It would also be interesting to investigate microcellulose amplification with other types of manufacturing methods, higher fiber ratios and other types of thermoplastics.

With the aim to develop and characterize a functionalized highly magnetic polymer carrier of micrometer size and of a narrow particle size distribution that will be suitable for biological application, hypercrosslinked microspheres were prepared. Simultaneously, the relation between structure and properties of product was observed. Condition of dispersion polymerization were optimized to obtain starting monodisperse poly(styrene-co-divinylbenzene) [P(St-DVB)] microspheres. The P(St-DVB) microspheres of different degree of crosslinking were prepared and effect of some polymerization parameters such as type of solvent, initiator, concentration and mode of DVB addition on morphology, size and particle size distribution were investigated. The starting microspheres were hypercrosslinked to obtain microporous inner structure. Hyperosslinked particles had very large specific surface area (> 1000 m2/g) and a high content of micropores (ca. 0.6 ml/g). First, P(St-DVB) microspheres were chloromethylated using three different chloromethylation agents to regulate their porous properties. Hypercrosslinking was achieved by the addition of stannic chloride as a catalyst and by increasing a temperature. The hypercrosslinked microspheres were then functionalized with sulfo- or aminogroups. The functional groups captured precipitated iron oxide inside the porous structure of the microspheres and also served as a reactive site for intended immobilization of the protein. A solution of ferrous and ferric chloride was imbibed under vacuum into the porous structure and the iron oxide was precipitated by an aqueous ammonia solution. Finally, the magnetic functionalized hypercrosslinked micropsheres were integrated into a biosensor for qualitative detection of ovalbumin.

This master‘s thesis deals with 3D printing for non-commercial RepRap 3D printer type and materials used in printing. The outcome of this work is a brief introduction to 3D printing, the theory of heat transfer and analysis of the two most important parts of the printer hot bed and hot end. To analyze and optimize the temperature profile of the hot bed and hot end are used Computer Aided Engineering systems CAD and CAE, SolidWorks and SolidWorks Flow Simulation.

The essence of the work is to test the possibilities specific type of simple 3D printing device, which has recently been getting more and more into the awareness of professionals and the general public. First, the work is focused on presentation 3D printing technology and current professional equipment, in the second part are experimentally evaluated possibilities of of a simple kind of 3D printers followed by assessment of the applicability of the device in engineering practice.

The theoretical part of this thesis is focused on bulk radical polymerization of styrene, methylmethacrylate, vinyltoluene and paramethylstyrene. It summarizes actual informations about kinetics and performance possibilities of bulk polymerization. Experimental part deals with polystyrene prepolymers preparation by bulk polymerization. The aim is to find optimal conditions for prepolymers preparation. Prepolymers should be usable for subsequent polymerization nearly up to 100% conversion. Conversion values were gravimetrically determined and molecular weights were obtained by viskosity measurements, which were realized by Ubbelohde viscometer. In the experimental part, there were performed simulations targeted on conversion dependence on time. The purpose was a prediction of monomer conversion at a given time during polymerization. Differences between reality and simulation were low in most of cases and the found form of kinetic behavior calculations provides satisfying results. In the conclusion of this thesis was suggested a new procedure for polystyrene prepolymers preparation.

The theoretical part is focused on evaluation of chosen ?essential? plastics used in the car industry. The principles of construction and proportioning of plastic components, basic conception of injection moulding and measuration follow. Another section of the theoretical part presents a summary of possible CAD systems, which are used. The practical part is focused on a particular plastic moulding. It includes the main description of a component with its material choice in dependence on the component function. Another section contains evaluation of the component complexity from the viewpoint of moulding, and a possible substitution of constructions, which could be productively simpler, is shown. The whole thesis is completed for better lucidity by pictures, drawings, and mechanical drawings.