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Polyedrisk oligomer silsesquioxane (POSS) är molekyler som har en inorganisk ryggrad med organiska grupper fa ̈sta utan på. Själva kåren har en bur liknande form och har en hög termisk stabilitet tack vare kisel (Si) och syre (O) som den består av. Det organiska grupperna som kan fästas på kåren kan variera för att få en molekyl som är anpassad för det material den ska blandas in i, tillexempel polyvinylklorid (PVC). POSS molekylerna kan blandas in i material antigen fysiskt eller kemiskt beroende på vilka organiska grupper molekylen består av. Tack vare den termiska stabiliteten POSS är på en intressant molekyl att använda som ett alternativt flamskyddsmedel till existerande flamskyddsmedel.  Det olika POSS materialen var producerade med lite olika reaktions parametrar och var gjorda av Funzionano AS i Norge, Porsgrunn. Materialet har bevarat olika lång tid men det olika POSS materialen har också olika funktionella grupper. Provet med namn SF458 211122 var också adderat till PVC materialet för att se om det påverkade PVC:s termiska egenskaper.  Syftet med detta master arbete är att kolla om tiden proverna bevaras, olika funktionella grupper och om olika reaktions parametrar kommer påverka det termiska egenskaperna. Dessa parametrar utforskas genom att använda analys instrumenten TGA/DSC och DSC. Men också för att se om POSS förbättrar PVC:s termiska egenskaper.  Resultaten visar att 3 av det 4 olika SF458 proverna hade liknande glasstransaktions temperaturer (Tg) som är runt 27 °C även om det förvarats olika lång tid. 1 av det 4 olika SF458 hade högre Tg vilket kan bero p ̊a att den syntesen hade andra reaktions förhållanden i sista reaktions steget bland annat. Smältpunkten och mängden prov kvar efter TGA analyserna kan påverkas av förvaringstiden eller reaktions förhållandena. För att få fram vad som påverkar vad måste mer forskning göras. / Polyhedral oligomeric silsesquioxane (POSS) are molecules with an inorganic backbone which has organics groups attached to the backbone. The backbone is like a cage and the functional groups are arms that goes out from the cage. The inorganic backbone does so the molecule has high thermal stability and the functional groups make it possible to tailor the molecule so it can be easier to physical or chemical blend it into a material, like thermoplastics. The thermal properties of POSS make it to an interesting alternative as a flame retardant since it is also not has hazardous as other common flame retardants.  The different POSS material have been synthesised with some different reaction parameters and were prepared by Funzionano AS in Norway, Porsgrunn. The material have been stored for different times but also the cage have different functional groups attached to it. POSS named SF458 211122 were also physically incorporated to polyvinyl chloride (PVC) to see if it have any effect on the thermal properties.  The aim of the study is to see if the time of storage, different functional groups and different synthesis parameters affect the thermal properties of the POSS material by using DSC and TGA/DSC instruments. But also to see if the thermal properties of PVC is improved when POSS is physically added.  The results showed that 3 of 4 of the different SF458 samples had similar glass transition temperatures (Tg), around 27 °C so the time of storage does not affect that property. Since 1 of the 4 samples had a higher Tg is probably due to other synthesis conditions. The affect in melting point and amount of residue can be effected by either the time of storage or the parameters for the synthesis. So, further research needs to be done.

At the royal institute of technology (KTH) in the department of applied process metallurgy, a novel modelling approach has been developed which allows a dynamic coupling between the commercial thermodynamic software Thermo-Calc and the commercial computational fluid dynamic (CFD) software Ansys Fluent, only referred to as Fluent in the study. The dynamic coupling approach is used to provide numerical CFD-models with thermodynamic data for the thermo-physical properties and for the fluid-fluid chemical reactions occurring in metallurgical processes. The main assumption forthe dynamic coupling approach is the existence of local equilibrium in each computational cell. By assuming local equilibrium in each computational cell it is possible to use thermodynamic data from thermodynamic databases instead of kinetic data to numerically simulate chemical reactions. The dynamic coupling approach has been used by previous studies to numerically simulate chemical reactions in metallurgical processes with good results. In order to validate the dynamic coupling approach further, experimental data is required regarding surface reactions. In this study, a graphiteand metallurgical coke oxidation experimental setup was suggested in order to provide the needed experimental data. With the experimental data, the ability of the dynamic couplings approach to numerically predict the outcome of surface reactions can be tested.By reviewing the literature, the main experimental apparatus suggested for the oxidationexperiments was a thermo-gravimetric analyzer (TGA). The TGA can provide experimental data regarding the reaction rate, kinetic parameters and mass loss as a function of both temperature and time. An experimental setup and procedure were also suggested.In order to test the ability of Fluent to numerically predict the outcome of surface reactions, without any implementation of thermodynamic data from Thermo-Calc, a benchmarking has been conducted. Fluent is benchmarked against graphite oxidation experiments conducted by Kim and No from the Korean advanced institute of science and technology (KAIST). The experimental graphite oxidation rates were compared with the numerically calculated graphite oxidation rates obtained from Fluent. A good match between the experimental graphite oxidation rates and the numerically calculated graphite oxidation rates were obtained. A parameter study was also conducted in order to study the effect of mass diffusion, gas flow rate and the kinetic parameters on the numerically calculated graphite oxidation rate. The results of the parameter study were partially supported by previous graphite oxidation studies. Thus, Fluent proved to be a sufficient numerical tool for numerically predicting the outcome of surface reactions regarding graphite oxidation at zero burn-off degree.

The purpose of this thesis is to examine the potential of a novel method for analysis and characterization of coal mine dust. Respirable dust has long been an industry concern due to the association of overexposure leading to the development occupational lung disease. Recent trends of increased incidence of occupational lung disease in miners, such as silicosis and Coal Workers Pneumoconiosis, has shown there is a need for a greater understanding of the respirable fraction of dust in underground coal mines. This study will examine the development of a comprehensive standard methodology for characterization of respirable dust via thermogravimetric analysis (TGA). This method was verified with laboratory-generated respirable dust samples analogous to those commonly observed in underground coal mines. Results of this study demonstrate the ability of the novel TGA method to characterize dust efficiently and effectively. Analysis of the dust includes the determination of mass fractions of coal and non-coal, as well as mass fractions of coal, carbonate, and non-carbonate minerals for larger respirable dust samples. Characterization occurs through the removal of dust particulates from the filter and analysis with TGA, which continuously measures change in mass with specific temperature regions associated with chemical changes for specific types of dust particulates. Results obtained from the verification samples reveal that this method can provide powerful information that may help to increase the current understanding of the health risks linked with exposure to certain types of dust, specifically those found in underground coal mines. / Master of Science

It has long been known that chronic exposures to high concentrations of respirable coal mine dust can lead to the development of lung diseases such as Coal Worker's Pneumoconiosis, commonly referred to as "black lung", and silicosis. Since the mid-1990s, an alarming resurgence of diseases has been documented in central Appalachia, where underground mining often necessitates significant extraction of rock strata along with the thin seams of coal. These circumstances have prompted concern over if or how changing dust composition might be a factor in contemporary disease prevalence. Until now, the total mass concentration and quartz mass fraction of respirable dust have been regulated and monitored in US coal mines. Unfortunately, however, these two metrics alone do not paint a full picture of dust composition. Earlier work in the author's research group established a preliminary thermogravimetric analysis (TGA) method for coal mine dust. The method is intended to allow estimation of three key mass fractions of the dust from separate sources: coal from the coal strata being mined; non-carbonate minerals from the rock strata being mined or drilled; and carbonates that are primarly sourced from application of rock dust products to the mine floor or ribs. However, accuracy of the preliminary method was substantially limited by poor dust recovery from the fibrous filter media used for sample collection. This thesis includes two studies: The first study aims to establish an improved TGA method. It uses smooth polycarbonate (PC) filters for dust sampling and a modified thermal ramping routine. The method is verified using laboratory-generated respirable dust samples. In the second study, the improved TGA method is used to analyze 75 respirable mine dust samples, collected in 15 US mines. Replicate samples are also analyzed by scanning electron microscopy using energy dispersive X-ray (SEM-EDX). TGA and SEM-EDX results are compared to gain insights regarding the analytical methods and general trends in dust composition within and between mines. / Master of Science / It has long been known that chronic exposures to excessive respirable coal mine dust can lead to the development of lung diseases such as Coal Worker’s Pneumoconiosis (“Black Lung”) and silicosis. Disease rates in central Appalachia have shown an alarming and unexpected increase since the mid-1990s, despite declining dust concentrations evident from regulatory compliance monitoring data. Clearly, there is a need to better understand coal mine dust composition, which will require additional analytical methods. Thermogravimetric analysis (TGA) has been proposed as one possible method, because it should allow estimation of three key dust components from separate sources: coal from the coal strata being mined; non-carbonate minerals from the rock strata being mined or drilled; and carbonates from application of rock dust products to the mine floor and ribs. However, preliminary work with TGA showed limited accuracy, mostly due to sampling materials. In this thesis, two studies were performed. The first study aims to establish an improved TGA method using smooth, polycarbonate (PC) filters. The second study demonstrates the method on a large number of mine dust samples, and compares the results to those gained by an alternative method that uses electron microscopy.

In this study, two quasi-isotropic carbon fiber-reinforced polyimide material systems, IM7/K3B and IM7/PETI-5, were thermally aged at 163°C for up to 3000 hours under a static compressive load. The future goal of this study is to determine the effect of 10,000 hours (currently underway) and possibly seven years of aging on these materials. The compressive load was applied using steel fixtures supplied by The Boeing Company. Back-to-back gages on the aging panels monitored compressive strain as well as bending strain. Following aging at 1500 and 3000 hours, ambient residual compression properties were assessed using the IITRI compression test method. Unexposed specimens were also tested to obtain baseline properties for comparison. These results showed that 3000 hours of stressed isothermal aging did not significantly affect the compressive properties of the two composite systems. A slight increase in scatter of the residual strength numbers was observed. Statistical evaluation of the results was used to compute design allowables and quantify changes in scatter. Differential scanning calorimetry (DSC) was used to monitor any changes in glass transition temperature as a result of the aging. Only small changes were observed in the DSC scans. Dynamic thermogravimetric analysis (TGA) tests were used to compare weight loss rate versus temperature results for the different age materials. Results show different rates of degradation occurring in the different K3B polymer aging histories. In addition to establishing the effect of isothermal aging under load on the compressive moduli and strength of two polymer-matrix composites, this experiment links increasing scatter in residual strength measurements to changing thermogravimetric results. / Master of Science

Inhalation of respirable dust in coal mines is a serious occupational health hazard which can lead to the development of chronic and irreversible lung diseases, such as Coal Worker's Pneumoconiosis (CWP) and Progressive Massive fibrosis (PMF). After the passage of the Federal Coal Mine Health and Safety Act (CMHSA) in the late 1960's the prevalence of CWP among US coal miners decreased. However, since the late 1990's a resurgence of lung diseases has been reported, particularly in central Appalachia. On the other hand, dust monitoring data suggest that concentrations of respirable coal mine dust (RCMD) and crystalline silica have been on a downward trend. This contradiction has prompted keen interest in detailed characterization of RCMD to shed light on dust constituents-and their sources. Such information might help miners understand where and under what conditions specific sources contribute to RCMD, and how dust controls and monitoring could be enhanced to mitigate the exposure to respirable hazards. Respirable dust particles generated in coal mines are generally associated with three primary sources: the coal strata that is mined and generates mostly coal particles that could contribute for lung diseases, the rock strata that is cut along with the coal and generates most of the respirable silica and silicates, and the rock dust products that are the main source of carbonates which could produce respiratory irritations. Thermogravimetric Analysis (TGA) is one of many analytical tools that might be used for dust characterization. Its primary benefit is that it can be used to apportion the total sample mass into three mass fractions (i.e., coal, carbonates, non-carbonates) which should be roughly associated with the primary dust sources (i.e., coal strata, rock dust products, rock strata) in many coal mines. This thesis consists of two main chapters: Chapter 1, outlines the research motivation, recaps the efforts to establish a standard TGA method for RCMD, and shows results of the validation experiments that were performed in the current work to enable application of the TGA method to a large set of RCMD and laboratory-generated dust samples. In Chapter 2, 46 lab-generated samples from primary dust source materials collected in 15 coal mines, and 129 respirable dust samples from 23 US coal mines are analyzed using the TGA method validated in Chapter 1. Results for both sets of samples are presented and the mine samples are interpreted based on sampling location, mining method and region. Additionally, Chapter 3 summarizes recommendations for future work. / Master of Science / The chronic exposure to dust generated in underground coal operations represents a serious health concern among coal miners that can lead to the development of lung diseases such as Coal Workers Pneumoconiosis (CWP or "black lung). Despite of dust compliance monitoring data that have shown that the concentrations of dust have been declining, since the late 1990's the number of US coal miners diagnosed with lung diseases has been increasing, especially in central Appalachia. This contradiction has prompted keen interest in detailed characterization of respirable coal mine dust (RCMD) to shed light on dust constituents-and their sources. Such information might help miners understand where and under what conditions specific sources contribute to RCMD, and how dust controls and monitoring could be enhanced to mitigate the exposure to respirable hazards. Thermogravimetric Analysis (TGA) has been proposed as an alternative approach for dust characterization. Its primary benefit is that it can be used to apportion the total sample mass into three mass fractions (i.e., coal, carbonates, non-carbonates) which should be roughly associated with the primary dust sources (i.e., coal strata, rock dust products, rock strata) in many coal mines. This thesis consists of two main chapters: Chapter 1, outlines the research motivation, recaps the efforts to establish a standard TGA method for RCMD, and shows results of the validation experiments that were performed in the current work to enable application of the TGA method to a large set of RCMD and laboratory-generated dust samples. In Chapter 2, 46 lab-generated samples from primary dust source materials collected in 15 coal mines, and 129 respirable dust samples from 23 US coal mines are analyzed using the TGA method validated in Chapter 1. Results for both sets of samples are presented and the mine samples are interpreted based on sampling location, mining method and region. Additionally, Chapter 3 summarizes recommendations for future work.