Preparation, properties and applications of wheat gluten edible films

Selostus: Syötävien gluteenikalvojen valmistus, ominaisuudt ja eräät käyttösovellukset

Preparation of Polysulfone Membranes

As it is known, a huge part of all commercially available membranes are prepared by immersion precipitation. This way is the primary way to get flat membranes. The advantages of immersion precipitation are: wide field of the polymers, which can be used (polymer must be soluble in a solvent or a solvent mixture) and ease of performing. The literature part of this work deals with phase inversion membrane preparation methods and casting parameters affecting membrane performance. Also some membrane types and materials are discussed. In the experimental part of this work 73 membrane samples were made with different casting parameters (polymer concentration in the casting solution and precipitation time) and tested for the retention and permeability. The results of these experiments are collected and combined into the figures and tables which are presented in this thesis. This work showed and confirmed connection between membrane performance and casting parameters (concentration of polymer in the casting solution and precipitation time).

Membrane emulsification in preparation of single site catalyst

In the theory part the membrane emulsification was studied. Emulsions are used in many industrial areas. Traditionally emulsions are prepared by using high shear in rotor-stator systems or in high pressure homogenizer systems. In membrane emulsification two immiscible liquids are mixed by pressuring one liquid through the membrane into the other liquid. With this technique energy could be saved, more homogeneous droplets could be formed and the amount of surfactant could be decreased. Ziegler-Natta and single-site catalysts are used in olefin polymerization processes. Nowadays, these catalysts are prepared according to traditional mixing emulsification. More homogeneous catalyst particles that have narrower particle size distribution might be prepared with membrane emulsification. The aim of the experimental part was to examine the possibility to prepare single site polypropylene catalyst using membrane emulsification technique. Different membrane materials and solidification techniques of the emulsion were examined. Also the toluene-PFC phase diagram was successfully measured during this thesis work. This phase diagram was used for process optimization. The polytetrafluoroethylene membranes had the largest contact angles with toluene and also the biggest difference between the contact angles measured with PFC and toluene. Despite of the contact angle measurement results no significant difference was noticed between particles prepared using PTFE membrane or metal sinter. The particle size distributions of catalyst prepared in these tests were quite wide. This would probably be fixed by using a membrane with a more homogeneous pore size distribution. It is also possible that the solidification rate has an effect on the particle sizes and particle morphology. When polymeric membranes are compared PTFE is probably still the best material for the process as it had the best chemical durability.

Centralized Motion Control of a Linear Tooth Belt Drive: Analysis of the Performance and Limitations

A centralized robust position control for an electrical driven tooth belt drive is designed in this doctoral thesis. Both a cascaded control structure and a PID based position controller are discussed. The performance and the limitations of the system are analyzed and design principles for the mechanical structure and the control design are given. These design principles are also suitable for most of the motion control applications, where mechanical resonance frequencies and control loop delays are present. One of the major challenges in the design of a controller for machinery applications is that the values of the parameters in the system model (parameter uncertainty) or the system model it self (non-parametric uncertainty) are seldom known accurately in advance. In this thesis a systematic analysis of the parameter uncertainty of the linear tooth beltdrive model is presented and the effect of the variation of a single parameter on the performance of the total system is shown. The total variation of the model parameters is taken into account in the control design phase using a Quantitative Feedback Theory (QFT). The thesis also introduces a new method to analyze reference feedforward controllers applying the QFT. The performance of the designed controllers is verified by experimentalmeasurements. The measurements confirm the control design principles that are given in this thesis.

Tooth-Coil Permanent Magnet Synchronous Machine Design for Special Applications

This doctoral thesis presents a study on the design of tooth-coil permanent magnet synchronous machines. The electromagnetic properties of concentrated non-overlapping winding permanent magnet synchronous machines, or simply tooth-coil permanent magnet synchronous machines (TC-PMSMs), are studied in details. It is shown that current linkage harmonics play the deterministic role in the behavior of this type of machines. Important contributions are presented as regards of calculation of parameters of TC-PMSMs,particularly the estimation of inductances. The current linkage harmonics essentially define the air-gap harmonic leakage inductance, rotor losses and localized temporal inductance variation. It is proven by FEM analysis that inductance variation caused by the local temporal harmonic saturation results in considerable torque ripple, and can influence on sensorless control capabilities. Example case studies an integrated application of TC-IPMSMs in hybrid off-highway working vehicles. A methodology for increasing the efficiency of working vehicles is introduced. It comprises several approaches – hybridization, working operations optimization, component optimization and integration. As a result of component optimization and integration, a novel integrated electro-hydraulic energy converter (IEHEC) for off-highway working vehicles is designed. The IEHEC can considerably increase the operational efficiency of a hybrid working vehicle. The energy converter consists of an axial-piston hydraulic machine and an integrated TCIPMSM being built on the same shaft. The compact assembly of the electrical and hydraulic machines enhances the ability to find applications for such a device in the mobile environment of working vehicles.Usage of hydraulic fluid, typically used in working actuators, enables direct-immersion oil cooling of designed electrical machine, and further increases the torque- and power- densities of the whole device.

Preparation for ramp-up production process in metal manufacturin

Collaboration is essential for successful new product development. In the preparation for ramp-up production collaboration between R&D and supply chain functions is crucial. This thesis examines the meaning of collaboration and the effects of collaboration between R&D and supply chain. The aim of this thesis is to analyse and advice on how to improve the collaboration between the research and development department and supply chain within the preparation for rampup process. This thesis begins by introducing the reader to the product development methodologies and collaboration literature. The following part of the thesis describes the current situation and the results of the qualitative research. The last part of the thesis will explain the improvement suggestions. The main improvement suggestions are clarification of the processes and responsibilities and the introduction of a kick-off meeting.

Novel technology for preparation of optically active chemicals

Asymmetric synthesis using modified heterogeneous catalysts has gained lots of interest in the production of optically pure chemicals, such as pharmaceuticals, nutraceuticals, fragrances and agrochemicals. Heterogeneous modified catalysts capable of inducing high enantioselectivities are preferred in industrial scale due to their superior separation and handling properties. The topic has been intensively investigated both in industry and academia. The enantioselective hydrogenation of ethyl benzoylformate (EBF) to (R)-ethyl mandelate over (-)-cinchonidine (CD)-modified Pt/Al2O3 catalyst in a laboratory-scale semi-batch reactor was studied as a function of modifier concentration, reaction temperature, stirring rate and catalyst particle size. The main product was always (R)-ethyl mandelate while small amounts of (S)-ethyl mandelate were obtained as by product. The kinetic results showed higher enantioselectivity and lower initial rates approaching asymptotically to a constant value as the amount of modifier was increased. Additionally, catalyst deactivation due to presence of impurities in the feed was prominent in some cases; therefore activated carbon was used as a cleaning agent of the raw material to remove impurities prior to catalyst addition. Detailed characterizations methods (SEM, EDX, TPR, BET, chemisorption, particle size distribution) of the catalysts were carried out. Solvent effects were also studied in the semi-batch reactor. Solvents with dielectric constant (e) between 2 and 25 were applied. The enantiomeric excess (ee) increased with an increase of the dielectric coefficient up to a maximum followed by a nonlinear decrease. A kinetic model was proposed for the enantioselectivity dependence on the dielectric constant based on the Kirkwood treatment. The non-linear dependence of ee on (e) successfully described the variation of ee in different solvents. Systematic kinetic experiments were carried out in the semi-batch reactor. Toluene was used as a solvent. Based on these results, a kinetic model based on the assumption of different number of sites was developed. Density functional theory calculations were applied to study the energetics of the EBF adsorption on pure Pt(1 1 1). The hydrogenation rate constants were determined along with the adsorption parameters by non-linear regression analysis. A comparison between the model and the experimental data revealed a very good correspondence. Transient experiments in a fixed-bed reactor were also carried out in this work. The results demonstrated that continuous enantioselective hydrogenation of EBF in hexane/2-propanol 90/10 (v/v) is possible and that continuous feeding of (-)-cinchonidine is needed to maintain a high steady-state enantioselectivity. The catalyst showed a good stability and high enantioselectivity was achieved in the fixed-bed reactor. Chromatographic separation of (R)- and (S)-ethyl mandelate originating from the continuous reactor was investigated. A commercial column filled with a chiral resin was chosen as a perspective preparative-scale adsorbent. Since the adsorption equilibrium isotherms were linear within the entire investigated range of concentrations, they were determined by pulse experiments for the isomers present in a post-reaction mixture. Breakthrough curves were measured and described successfully by the dispersive plug flow model with a linear driving force approximation. The focus of this research project was the development of a new integrated production concept of optically active chemicals by combining heterogeneous catalysis and chromatographic separation technology. The proposed work is fundamental research in advanced process technology aiming to improve efficiency and enable clean and environmentally benign production of enantiomeric pure chemicals.

Lipase and omega-transaminase catalysis in preparation of alcohol and amine enantiomers

Enantiopure intermediates are of high value in drug synthesis. Biocatalysis alone or combined with chemical synthesis provides powerful tools to access enantiopure compounds. In biocatalysis, chemo-, regio- and enantioselectivity of enzymes are combined with their inherent environmentally benign nature. Enzymes can be applied in versatile chemical reactions with non-natural substrates under synthesis conditions. Immobilization of an enzyme is a crucial part of an efficient biocatalytic synthesis method. Successful immobilization enhances the catalytic performance of an enzyme and enables its reuse in successive reactions. This thesis demonstrates the feasibility of biocatalysis in the preparation of enantiopure secondary alcohols and primary amines. Viability and synthetic usability of the studied biocatalytic methods have been addressed throughout this thesis. Candida antarctica lipase B (CAL-B) catalyzed enantioselective O-acylation of racemic secondary alcohols was successfully incorporated with in situ racemization in the dynamic kinetic resolution, affording the (R)-esters in high yields and enantiopurities. Side reactions causing decrease in yield and enantiopurity were suppressed. CAL-B was also utilized in the solvent-free kinetic resolution of racemic primary amines. This method produced the enantiomers as (R)-amides and (S)-amines under ambient conditions. An in-house sol-gel entrapment increased the reusability of CAL-B. Arthrobacter sp. omega-transaminase was entrapped in sol-gel matrices to obtain a reusable catalyst for the preparation enantiopure primary amines in an aqueous medium. The obtained heterogeneous omega-transaminase catalyst enabled the enantiomeric enrichment of the racemic amines to their (S)-enantiomers. The synthetic usability of the sol-gel catalyst was demonstrated in five successive preparative kinetic resolutions.

Studies in selectivity of lipases in preparation of cyanohydrins, sugar conjugates and secondary alcohols

Biocatalysis can be applied in organic synthetic chemistry to counter challenges posed by increased demands towards chemo-, regio- and stereoselectivity, not forgetting the need for greener chemistry. During the last 30 years, biocatalysis with the use of enzymes as chiral catalysts has become more common in chemistry laboratories and industrial processes. In this thesis, the use of lipases as versatile biocatalysts in the acylation of alcohols is examined both in the light of literature examples and four original publications. In the first part of the work presented in this thesis lipases were utilized in two examples concerning secondary alcohols. First, the kinetic resolution of heterocyclic aromatic secondary alcohols through transesterification was thoroughly examined including the studies of competing hydrolysis and esterification reactions. In another example, lipases were utilized in the formation of a dynamic systemic resolution (DSR) process which in turn was used as a developmental tool in the optimization of the dynamic kinetic resolution (DKR) of five heterocyclic aromatic cyanohydrins in one pot for the preparation of cyanohydrin esters as single enantiomers. In the second part of the work, the regio- and stereoselectivity of lipases was used to form sugar conjugates of glyceric and β-amino acids. The primary hydroxyl groups of methyl α-D-galacto-, -gluco- and -mannopyranosides were now acylated trough lipasecatalyzed transesterification and enantioselective lipase-catalyzed ring-opening of β- lactams, respectively.