Unsaturated Polyester Resins from Recycled Polyethyleneterephthalate

Tämän diplomityön tarkoituksena oli tutkia miten kuluttajien kierrättämästä polyeteenitereftalaatista ( PET ) voi valmistaa tyydyttymättömiä polyesterihartseja. Työssä valmistettiin yleiskäyttöön soveltuva laminointihartsi sekä 'gel coat' -hartsi jota käytetään esim. veneiden pintamaalina. Yleishartsin depolymerointiin käytettiin propyleeniglykolia ja 'gel coat' -hartsin valmistamiseen neopentyyliglykolia. Polykondensaatiovaiheessa reaktioon lisättiin maleiinihappoa ja lopuksi hartsit liuotettiin styreeniin. Kirjallisuusosassa esitetään eri menetelmiä PET:n depolymeroimiseksi. Lisäksi esitetään eri vaihtoehtoja glykolien, happojen, katalyyttien ja vinyylimonomeerien valitsemiseksi tyydyttymättömien polyesterihartsien valmistuksessa. Analyysimenetelmiä nestemäisten ja kovetettujen hartsien tutkimiseen ja vertailuun käydään läpi kuten myös erilaisia sovelluksia polyesterihartsien käyttämiseksi. Kokeellinen osa todisti että PET-pullojäte voidaan prosessoida hartsiksiilman uusia investointeja prosessilaitteistoon. PET:n glykolyysi kesti viidestäseitsemään tuntia ja polykondensaatiovaihe kahdesta ja puolesta viiteen tuntiin. Hartsien molekyylipainot ja mekaanisten testien tulokset olivat vertailukelpoisia kaupallisten hartsien antamien tulosten kanssa. Glykolyysivaiheen momomeeri- ja oligomeeripitoisuudet mitattiin geelipermeaatiokromatografialla, jotta nähtiin miten pitkälle depolymerisaatio oli edennyt. Tätä tietoa voidaan hyödyntää uusien hartsireseptin suunnittelussa. Polymeeriketjussa jäljellä olevien C=C kaksoissidosten määrä ja niiden isomeraatioaste maleaattimuodosta fumaraattimuotoon mitattiin 1H-NMR -menetelmällä. Tislevesien koostumus määritettiin kaasukromatografialla, ja tulokset kertoivat katalyytin sisältämän kloorin reagoineen glykolien kanssa, johtaen suureen glykolikulutukseen ja muihin ei-toivottuihin sivureaktioihin. Hartsien sietokykyä auringon valolle mitattiin niiden UV-absorption avulla. Kummastakin hartsista valmistettiin 'gel coat' -maalit jotkalaitettiin sääkoneeseen, joka simuloi auringonpaistetta ja vesisadetta vuorotellen. Näistä 'gel coateista' mitattiin niiden kellastumista. Kummastakin hartsista tehdyt valut asetettiin myös sääkoneeseen ja IR-spektreistä ennen jajälkeen koetta nähtiin että C=O ja C-O esterisidoksia oli hajonnut.

Liquid cooling solutions for rotating permanent magnet synchronous machines

In the design of electrical machines, efficiency improvements have become very important. However, there are at least two significant cases in which the compactness of electrical machines is critical and the tolerance of extremely high losses is valued: vehicle traction, where very high torque density is desired at least temporarily; and direct-drive wind turbine generators, whose mass should be acceptably low. As ever higher torque density and ever more compact electrical machines are developed for these purposes, thermal issues, i.e. avoidance of over-temperatures and damage in conditions of high heat losses, are becoming of utmost importance. The excessive temperatures of critical machine components, such as insulation and permanent magnets, easily cause failures of the whole electrical equipment. In electrical machines with excitation systems based on permanent magnets, special attention must be paid to the rotor temperature because of the temperature-sensitive properties of permanent magnets. The allowable temperature of NdFeB magnets is usually significantly less than 150 ˚C. The practical problem is that the part of the machine where the permanent magnets are located should stay cooler than the copper windings, which can easily tolerate temperatures of 155 ˚C or 180 ˚C. Therefore, new cooling solutions should be developed in order to cool permanent magnet electrical machines with high torque density and because of it with high concentrated losses in stators. In this doctoral dissertation, direct and indirect liquid cooling techniques for permanent magnet synchronous electrical machines (PMSM) with high torque density are presented and discussed. The aim of this research is to analyse thermal behaviours of the machines using the most applicable and accurate thermal analysis methods and to propose new, practical machine designs based on these analyses. The Computational Fluid Dynamics (CFD) thermal simulations of the heat transfer inside the machines and lumped parameter thermal network (LPTN) simulations both presented herein are used for the analyses. Detailed descriptions of the simulated thermal models are also presented. Most of the theoretical considerations and simulations have been verified via experimental measurements on a copper tooth-coil (motorette) and on various prototypes of electrical machines. The indirect liquid cooling systems of a 100 kW axial flux (AF) PMSM and a 110 kW radial flux (RF) PMSM are analysed here by means of simplified 3D CFD conjugate thermal models of the parts of both machines. In terms of results, a significant temperature drop of 40 ̊C in the stator winding and 28 ̊C in the rotor of the AF PMSM was achieved with the addition of highly thermally conductive materials into the machine: copper bars inserted in the teeth, and potting material around the end windings. In the RF PMSM, the potting material resulted in a temperature decrease of 6 ̊C in the stator winding, and in a decrease of 10 ̊C in the rotor embedded-permanentmagnets. Two types of unique direct liquid cooling systems for low power machines are analysed herein to demonstrate the effectiveness of the cooling systems in conditions of highly concentrated heat losses. LPTN analysis and CFD thermal analysis (the latter being particularly useful for unique design) were applied to simulate the temperature distribution within the machine models. Oil-immersion cooling provided good cooling capability for a 26.6 kW PMSM of a hybrid vehicle. A direct liquid cooling system for the copper winding with inner stainless steel tubes was designed for an 8 MW directdrive PM synchronous generator. The design principles of this cooling solution are described in detail in this thesis. The thermal analyses demonstrate that the stator winding and the rotor magnet temperatures are kept significantly below their critical temperatures with demineralized water flow. A comparison study of the coolant agents indicates that propylene glycol is more effective than ethylene glycol in arctic conditions.

α-Pinene oxide and verbenol oxide isomerizations over heterogeneous catalysts

Terpenes are a valuable natural resource for the production of fine chemicals. Turpentine, obtained from biomass and also as a side product of softwood industry, is rich in monoterpenes such as α-pinene and β-pinene, which are widely used as raw materials in the synthesis of flavors, fragrances and pharmaceutical compounds. The rearrangement of their epoxides has been thoroughly studied in recent years, as a method to obtain compounds which are further used in the fine chemical industry. The industrially most desired products of α-pinene oxide isomerization are campholenic aldehyde and trans-carveol. Campholenic aldehyde is an intermediate for the manufacture of sandalwood-like fragrances such as santalol. Trans-carveol is an expensive constituent of the Valencia orange essence oil used in perfume bases and food flavor composition. Furthermore it has been found to exhibit chemoprevention of mammary carcinogenesis. A wide range of iron and ceria supported catalysts were prepared, characterized and tested for α-pinene oxide isomerization in order to selective synthesis of above mentioned products. The highest catalytic activity in the preparation of campholenic aldehyde over iron modified catalysts using toluene as a solvent at 70 °C (total conversion of α-pinene oxide with a selectivity of 66 % to the desired aldehyde) was achieved in the presence of Fe-MCM-41. Furthermore, Fe-MCM-41 catalyst was successfully regenerated without deterioration of catalytic activity and selectivity. The most active catalysts in the synthesis of trans-carveol from α-pinene oxide over iron and ceria modified catalysts in N,N-dimethylacetamide as a solvent at 140 °C (total conversion of α-pinene oxide with selectivity 43 % to trans-carveol) were Fe-Beta-300 and Ce-Si-MCM-41. These catalysts were further tested for an analogous reaction, namely verbenol oxide isomerization. Verbenone is another natural organic compound which can be found in a variety of plants or synthesized by allylic oxidation of α-pinene. An interesting product which is synthesized from verbenone is (1R,2R,6S)-3-methyl-6-(prop-1-en-2-yl)cyclohex-3-ene-1,2-diol. It has been discovered that this diol possesses potent anti-Parkinson activity. The most effective way leading to desired diol starts from verbenone and includes three stages: epoxidation of verbenone to verbenone oxide, reduction of verbenone oxide and subsequent isomerization of obtained verbenol oxide, which is analogous to isomerization of α-pinene oxide. In the research focused on the last step of these synthesis, high selectivity (82 %) to desired diol was achieved in the isomerization of verbenol oxide at a conversion level of 96 % in N,N-dimethylacetamide at 140 °C using iron modified zeolite, Fe-Beta-300. This reaction displayed surprisingly high selectivity, which has not been achieved yet. The possibility of the reuse of heterogeneous catalysts without activity loss was demonstrated.