D. Tech. (Department of Chemistry, Faculty of Applied and Computer Sciences), Vaal University of Technology / In the present era of water resources scarcity, efficient treatment of wastewater is a major prerequisite especially for growing economy. Numerous approaches have been studied for the development of cheaper and more effective adsorbents for removal of both organic and inorganic pollutants from wastewater. The present study seeks to harness the potential of biosorption and nanotechnology by producing more efficient, selective, mechanically stable and effective adsorbents for removal of organic and inorganic pollutants. The biosorbent-magnetic nanomaterial was synthesized by coating magnetite nanoparticles with sodium hydroxide treated pine cone by co-precipitation method. Magnetite coated pine bio-composite was then modified by cross-linking with hexamethylene diisocyanate and epichlorohydrin to the molecular recognition compound “cyclodextrin”. These novel biosorbent-magnetic nanoparticle materials were explored in overcoming the drawbacks of the biosorbent alone and selectively remove inorganic and organic pollutants from complex matrices. The synthesized materials were characterized by several analytical techniques including, Fourier Transformed Infrared Spectroscopy (FTIR), Thermogravimetric analysis (TGA), X-Ray Diffraction (XRD), Scanning Electron Microscopy-Energy Dispersive X-Ray (SEM–EDX), Transmission Electron Microscopy (TEM), Brunauer, Emmett and Teller Isotherm (BET) surface area analysis, X-ray Photoelectron Spectroscopy (XPS), Vibrating Sample Magnetometer (VSM) and pH at point of zero charge (pHpzc). Sodium hydroxide treated pine cone and magnetite coated pine cone were applied for both chromium(VI) and arsenic(III) adsorption while the magnetite coated pine cone, magnetite coated pine cone crosslinked to cyclodextrin using both epichlorohydrin and hexamethylene diisocyanate were applied for 4-nitrophenol removal from aqueous solution. Batch adsorption studies were performed to optimize operating parameters such as solution pH, adsorbent dose, contact time, temperature and initial concentration. Pseudo first, pseudo second, intraparticle diffusion, pore and film diffusion kinetic models were determined to investigate the mechanism of adsorption process. Coefficient of correlation, r2, and variable error, methods were also applied in the determination of the best fit of the kinetic method. Structural characterization of magnetite coated pine cone and the magnetite coated pine crosslinked to cyclodextrin using 1,6-hexamethylene diisocyanate and epichlorohydrin were confirmed by characterization techniques applied. The adsorption of Cr(VI), As(III) and 4-nitrophenol was found to be dependent on the solution pH, adsorbent dose, initial concentration, temperature and ionic strength. Kinetic modelling revealed that the adsorption of Cr(VI), As(III) and 4-nitrophenol is controlled by pseudo second order kinetic model suggesting surface adsorption and intraparticle diffusion model. Intraparticle, pore and film diffusion models gave further insight into the controlling diffusion mechanism involved in the adsorption process for all pollutants investigated. Equilibrium studies indicated that the adsorption of all pollutants followed Langmuir isotherm indicating that adsorption sites are homogeneous in nature. The obtained thermodynamic parameters demonstrated that the adsorption of Cr(VI), As(III) and 4-nitrophenol were spontaneous, favourable and endothermic in nature. Anionic effect positively affected Cr(VI) and As(III) removal but had a negative effect on the 4-nitrophenol adsorption. Adsorption of 4-nitrophenol onto the nanocomposite adsorbents was attributed to multiple adsorbent-adsorbate interactions such as hydrogen bonding, hydrophobic attraction and guest host interaction. Magnetite coated pine better removed Cr(VI) and As(III) from aqueous solution than NaOH treated pine cone biomaterial while the magnetite coated pine crosslinked to cyclodextrin using 1,6-hexamethylene diisocyanate exhibited better adsorption performance for 4-nitrophenol removal than the nanocomposite crosslinked using epichlorohydrin and the magnetite coated pine cone.

Spray Polyurethane Foam insulation (SPF) kits are currently being marketed and sold to do-it-yourselfers to meet various insulating needs. Like commercial SPF systems, the primary health concern with SPF kits is user overexposure to the isocyanates during product application. The potential health risk associated with SPF applications is driven by several factors including (but not limited to): the toxicity of isocyanates; the potentially high exposure intensity; the quantity of isocyanates used in the process; the enclosed nature of the environment in which the product could be applied; the potentially high exposure duration/frequency; and the limited availability of control measures to reduce agent intensity (e.g., personal protective equipment, dilution ventilation). To better understand the potential hazards associated with the use of SPF kits, the current study was designed to provide an initial characterization of user exposure to airborne particulate during the application process. Specifically, the study would aim to answer the following: * What is the particle size distribution of the aerosol a SPF kit user is exposed to during application? * What is the airborne particle mass concentration a SPF kit user is exposed to during application? To answer these questions, a single commercially available SPF kit was selected for use and a mock residential environment was constructed to support repeated applications of SPF. Size-selective and total dust air sampling were conducted during the applications to determine the particle size distribution and mass concentration of aerosols generated by the selected kit. The particle size distributions developed from the size selective sampling results showed the presence of airborne particulate capable of penetration to the gas exchange regions of the respiratory tract. The average mass median diameter and geometric standard deviation of the particle size distributions were 4.6 µm and 2.7 respectively. The total dust sampling results showed mean airborne concentrations of 10.40 mg/m3. Based on the sampling results the study, personal air monitoring is needed to assess the degree of user exposure to methylene diphenyl diisocyanate (MDI) and to provide information for the selection of exposure control methods.

Fundação Carlos Chagas Filho de Amparo a Pesquisa do Estado do Rio de Janeiro / Neste estudo, o comportamento em solução diluída de pré-polímeros uretânicos à base de poli(glicol propilênico) (PPG) e diisocianato de isoforona (IPDI) foi avaliado por medidas viscosimétricas a 30 C em dois tipos de solventes, com diferentes polaridades: isopropanol e tolueno. Os pré-polímeros foram sintetizados em massa, ou seja, na ausência de qualquer solvente, e nas formulações foram variadas as razões entre o número de equivalentes-grama de grupamentos isocianato e hidroxila [NCO/OH] e a massa molar do PPG. Os pré-polímeros foram caracterizados por espectrometria na região do infravermelho. No tratamento matemático dos dados viscosimétricos, foram empregadas cinco diferentes equações para determinar os valores de viscosidade intrínseca: Huggins; Kraemer e Schulz-Blaschke, por extrapolação gráfica; e Solomon-Ciuta; Deb-Chanterjee e; novamente, Schulz-Blaschke, para determinações por um único ponto. Os valores de viscosidade intrínseca obtidos pelos dois métodos (extrapolação gráfica e por um único ponto) foram comparados a fim de se verificar a validade da determinação por um único ponto para os sistemas analisados, bem como determinar qual equação seria a mais adequada para esse tipo de cálculo. Foram calculadas as constantes viscosimétricas de Huggins, Kraemer e Schulz-Blaschke, e foi feita uma análise da qualidade do solvente. / In this study the behavior of urethanes prepolymers based on poly(propylene glycol) (PPG) and isophorone diisocyanate (IPDI), in diluted solutions, were studied by viscosimetric measurements, at 30 C, in two types of solvents with different polarities: isopropyl alcohol and toluene. The prepolymers were synthesized in bulk, i.e, in the absence of solvent. In the formulations were varied the ratio between the equivalent-grams number of isocyanate functional groups and hydroxyl group [NCO/OH] and PPG molecular mass. The prepolymers were characterized by infrared spectrometry (FTIR). Five different equations were used to determine intrinsic viscosities values: Huggins; Kraemer and Schulz-Blaschke, by graphic extrapolation; and Solomon-Ciuta; Deb-Chanterjee and; again, Schulz-Blaschke, by a single point determination. The intrinsic viscosities values obtained by two methods (graphic extrapolations and through a single point determination) were compared in order to verify the validity of the single point determination for the systems studied, as well as the more accurate equation for this type of calculation. Viscometric constants from Huggins; Kraemer and Schulz-Blaschke equations were also determined to verify solvent quality.

Fundação Carlos Chagas Filho de Amparo a Pesquisa do Estado do Rio de Janeiro / Neste estudo, o comportamento em solução diluída de pré-polímeros uretânicos à base de poli(glicol propilênico) (PPG) e diisocianato de isoforona (IPDI) foi avaliado por medidas viscosimétricas a 30 C em dois tipos de solventes, com diferentes polaridades: isopropanol e tolueno. Os pré-polímeros foram sintetizados em massa, ou seja, na ausência de qualquer solvente, e nas formulações foram variadas as razões entre o número de equivalentes-grama de grupamentos isocianato e hidroxila [NCO/OH] e a massa molar do PPG. Os pré-polímeros foram caracterizados por espectrometria na região do infravermelho. No tratamento matemático dos dados viscosimétricos, foram empregadas cinco diferentes equações para determinar os valores de viscosidade intrínseca: Huggins; Kraemer e Schulz-Blaschke, por extrapolação gráfica; e Solomon-Ciuta; Deb-Chanterjee e; novamente, Schulz-Blaschke, para determinações por um único ponto. Os valores de viscosidade intrínseca obtidos pelos dois métodos (extrapolação gráfica e por um único ponto) foram comparados a fim de se verificar a validade da determinação por um único ponto para os sistemas analisados, bem como determinar qual equação seria a mais adequada para esse tipo de cálculo. Foram calculadas as constantes viscosimétricas de Huggins, Kraemer e Schulz-Blaschke, e foi feita uma análise da qualidade do solvente. / In this study the behavior of urethanes prepolymers based on poly(propylene glycol) (PPG) and isophorone diisocyanate (IPDI), in diluted solutions, were studied by viscosimetric measurements, at 30 C, in two types of solvents with different polarities: isopropyl alcohol and toluene. The prepolymers were synthesized in bulk, i.e, in the absence of solvent. In the formulations were varied the ratio between the equivalent-grams number of isocyanate functional groups and hydroxyl group [NCO/OH] and PPG molecular mass. The prepolymers were characterized by infrared spectrometry (FTIR). Five different equations were used to determine intrinsic viscosities values: Huggins; Kraemer and Schulz-Blaschke, by graphic extrapolation; and Solomon-Ciuta; Deb-Chanterjee and; again, Schulz-Blaschke, by a single point determination. The intrinsic viscosities values obtained by two methods (graphic extrapolations and through a single point determination) were compared in order to verify the validity of the single point determination for the systems studied, as well as the more accurate equation for this type of calculation. Viscometric constants from Huggins; Kraemer and Schulz-Blaschke equations were also determined to verify solvent quality.

Cette thèse porte sur la synthèse de polyuréthanes thermoplastiques plus durables à partir de dérivés des huiles végétales. La première voie étudiée est basée sur la réaction, largement utilisée, entre un diol et un diisocyanate. Aussi, pour s’affranchir de l’utilisation des diisocyanates toxiques, une approche via la polyaddition entre un bis carbonate cyclique et une diamine a également été étudiée. Pour ce faire des précurseurs bi-fonctionnels : diols, bis carbonates cycliques à 5 et 6 chainons et diamines ont été préparés à partir de dérivés de l’huile de tournesol (oléate de méthyle) et de l’huile de ricin (undécénoate de méthyle et acide sébacique). Les propriétés thermo-mécaniques des polyuréthanes et poly(hydroxyuréthane)s thermoplastiques obtenus ont pu être ajustées par le choix adapté de la structure chimique des précurseurs (gras) utilisés. Les travaux réalisés démontrent un effet de la taille du cycle du carbonate sur la réactivité. En effet, les (bis) carbonates cycliques à 6 chainons se sont avérés plus réactifs que leurs homologues à 5 chainons. De plus, la synthèse de diamines via un intermédiaire dinitrile semble très prometteuse pour le « design » d’une plateforme de diamines issues d’acides gras et de poly(hydroxyuréthane)s entièrement bio-sourcés. / This thesis aims to synthesize more sustainable thermoplastic polyurethanes from vegetable oil derivatives. The first route that has been investigated is based on the well-known reaction between a diol and a diisocyanate. Then to avoid the use of diisocyanates, the route via the polyaddition of a bis cyclic carbonate and a diamine have been studied as well. For this purpose, bifunctional precursors such as diols, bis 5- and 6-membered cyclic carbonates and diamines have been prepared from sunflower oil derivative (methyl oleate) and castor oil derivatives (methyl undecenoate and sebacic acid) The thermo-mechanical properties of the PUs have been modulated by designing and selecting the chemical structure of the (fatty acid-based) monomers. The performed model reaction kinetics revealed the higher reactivity of the 6-membered cyclic carbonates compare to the 5-membered ones. Finally, the developed route to fatty acid-based diamines via dinitriles synthesis in mild conditions was really efficient and this route is really promising to develop a fatty acid based-diamines platform and fully bio-based poly(hydroxyurethane)s.

The diploma thesis is focused on a detection and a laboratory control of hazardous substances’ leak into the environment. These hazardous substances are classified. Further, it aims to chemical laboratories of the fire-brigade of the Czech Republic, as well as which place they hold in the fire-brigade system, and it indicates their main duties. This diploma thesis contains a review of some essential types of devices and mediums, which are in terms of the fire-brigade of the Czech Republic usable to practice the detection, determination and assessment of the hazardous substances in various figures of the environment in terrain, i.e. filling of duties of the chemical survey. The output of this diploma thesis is simulation of leaks of the toluene diisocyanate using ALOHA software, TerEx software and Rozex Alarm software. Further on, the proposal of another methodical sheet focused on leak actions of the concrete hazardous industrial substance – toluene diisocyanate. This methodical sheet could therefore broaden pro tempore elaborated sheets for chlorine and ammonia.

Die Arbeit beschreibt neuartige Isocyanat- und Initiierungsreaktionen von speziellen Basen mit dem Imin-Strukturinkrement. Gegenstand des ersten Teils ist die Synthese und Charakterisierung neuer Imidazolin-Isocyanat-Adduksysteme, welche genutzt werden um organische Netzwerke auf der Basis von 1-Ethylimidazolin und diversen Diisocyanaten aufzubauen. Ferner wurden die unterschiedlichen Adduktsysteme hinsichtlich ihrer Anwendbarkeit als blockierte Isocyanate untersucht. Hierzu wurden thermische Analysen wie DSC- und TG-MS-Messungen durchgeführt. Durch experimentelle Ergebnisse und quantenchemische Rechnungen konnte ein neuartiger Reaktionsmechanismus einer Adduktbildung gefunden werden. Die Imidazolin-Isocyanat-Adduktnetzwerke wurden als Macroinitiatoren für die radikalische Polymerisation von Methylmethacrylat (MMA) verwendet, wodurch Adduktnetzwerk-PMMA-Kompositmaterialien erhalten wurden. Gegenstand des zweiten Teils dieser Arbeit ist die Entwicklung eines neuartigen Initiatorsystems für die radikalische Polymerisation von MMA und Styrol, auf der Grundlage der Iminbase-(Meth-)Acrylat-induzierten Polymerisation (IBA-Polymerisation). Hierzu wurden unterschiedlich substituierte Isoxazolone synthetisiert und als Starter für die Polymerisation eingesetzt. Der radikalische Charakter der Polymerisation wurde mittels Copolymerisationsexperimenten belegt.:Abkürzungsverzeichnis 1. Einleitung und Zielsetzung 1.1. Einleitung 1.2. Zielsetzung und Motivation 2. Theoretische Grundlagen 2.1. Isocyanat-Imidazolin-Adduktsysteme als blockierte Isocyanate 2.1.1. Blockierte Isocyanate 2.1.2. Iminbasen-Isocyanat-Addukte 2.2. Radikalische Polymerisation 2.2.2. Autoinitiierung von Styrol und Methylmethacrylat 2.2.3. Definition der IBA- und IBI-Polymerisation 3. Ergebnisse und Diskussion 3.1. Isocyanat-Imidazolin-Adduktsysteme als blockierte Isocyanate 3.1.1. 3 : 1-Isocyanat-Imidazolin-Addukte basierend auf 1-Ethylimidazolin 3.1.2. Organische Netzwerke basierend auf 3 : 1-Isocyanat-Imidazolin-Addukten 3.1.3. 2 : 1-Isocyanat-Imidazolin-Addukte basierend auf 1-Ethyl-2-iso-propyl-imidazolin 3.1.4. 2 : 1-Isocyanat-Imidazolin-Addukte basierend auf 1-Ethyl-2-methyl-imidazolin 3.2. IBA-Polymerisation mittels Isoxazolonen 3.2.1. Tautormerie und thermische Analysen von Isoxazolonderivaten 3.2.2. Polymerisation von Acrylatmonomeren mit Isoxazolonen 3.2.3. Kinetik der IBA-Polymerisation mit Isoxazolonen 3.2.4. IBA-Polymerisation von Styrol mit 3-Phenyl-5-isoxazolon 3.2.5. Mechanistische Studien der IBA-Polymerisation initiiert durch Isoxazolone 4. Zusammenfassung und Ausblick 5. Experimenteller Teil 5.1. Geräte und Chemikalien 5.2. Synthese der Iminbasen 5.3. Synthese der Iminbase–Isocyanat–Addukte 5.4. Synthese der 3 : 1 Adduktnetzwerke 5.5. Synthese von Isoxazolonderivaten 5.6. Polymerisationen von MMA und Styrol mit Isoxazolonen 6. Literatur 7. Anhang Danksagung Lebenslauf Liste an Veröffentlichungen Selbstständigkeitserklärung

Kemiska arbetsmiljörisker förekommer inom ett flertal branscher och behöver förebyggas för att skydda arbetstagare mot ohälsa, sjukdom och olycksfall. Det förebyggande arbetet görs genom att identifierade risker bedöms och kontrolleras med ändamålsenliga åtgärder, med målet att riskerna minskar eller helt försvinner. Att genomföra kemiska riskbedömningar är dock ofta både svårt och komplext med många olika aspekter att beakta och kräver både tid och kunskap. Som ett sätt att förenkla och effektivisera processen kring kemisk riskbedömning önskar Skanska, ett företag inom bygg- och anläggningsbranschen, se över om det är möjligt att återanvända kemiska riskbedömningar. Syftet med detta examensarbete blev därmed att utreda möjligheten i återanvändning av redan genomförda kemiska riskbedömningar där de kemiska produkterna ska användas igen. Utredningen har fokuserat på fördelar, hinder eller svårigheter och förutsättningar för återanvändning. Europeiskt och svenskt regelverk och vetenskaplig litteratur har genomlysts och data har samlats in från intervjuer med olika nyckelpersoner på tre arbetsplatser inom Skanska samt utifrån riskbedömningar av några utsedda produkter. Resultatet har därefter jämförts med svenskt regelverk, för att därigenom dra slutsatser om möjligheten i återanvändning av kemiska riskbedömningar. Examensarbetet har resulterat i slutsatsen att återanvändning av kemiska riskbedömningar bör vara möjlig, under förutsättning att de mallar eller checklistor som används som stöd uppfyller de krav som finns för kemisk riskbedömning. Det behöver säkerställas genom ändamålsenliga rutiner av personal med rätt kompetens om kemiska arbetsmiljörisker. Det behöver också stämmas av att exempelvis arbetssätt, omgivning och tillgången av åtgärder är likvärdiga på den arbetsplats som först genomfört riskbedömningen, och den arbetsplats som därefter återanvänder riskbedömningen, eller att dessa faktorer kan bli likvärdiga genom vidtagna åtgärder. Några risker eller hinder för återanvändning har identifierats. En av de mest framträdande riskerna är att kemiska arbetsmiljörisker förbises i samband med återanvändningen och därigenom också de åtgärder som behöver vidtas. Orsaker till detta kan vara bristande kunskap och engagemang eller möjligen fusk och slarv. I situationer där arbete ska ske med farligare kemiska produkter kan det vara svårare med återanvändning av riskbedömningar. Några fördelar med återanvändning bedöms vara förkortad tidsåtgång för kemiska riskbedömningar, en effektivare hantering, samt ett ökat stöd och lärande om kemiska arbetsmiljörisker genom att man lär av varandra och tidigare riskbedömningar. Möjligen kan återanvändning också bidra till att fler riskbedömningar genomförs, för att därigenom trygga yrkesarbetarnas säkerhet och hälsa. / Chemical risks in the work environment occur in several industries, and need to be prevented to protect workers from ill-health, illness and accidents. By performing risk assessments and taking appropriate measures, it is possible to reach the goal to reduce or even eliminate chemical risks. However, performing chemical risk assessments is often a quite difficult and complex issue with several different aspects to consider, requiring both time and knowledge. As a way to simplify and streamline the process of chemical risk assessment, Skanska, a company within the construction industry, wants to investigate whether it is possible to reuse chemical risk assessments. The purpose of this thesis was thus to investigate the possibility of reusing already performed chemical risk assessments in situations where the chemical products will be used again. The investigation has focused on the advantages, obstacles or difficulties and prerequisites for reuse. European and Swedish regulations and scientific literature have been reviewed and data have been collected from interviews with managers, safety representatives and employees at three workplaces at Skanska and from performed risk assessments of some selected products. Thereafter, the results have been compared with Swedish regulations, in order to draw conclusions about the possibility of reusing chemical risk assessments. The conclusion is that it should be possible to reuse chemical risk assessments, provided that the templates or checklists used as a support meet the requirements for chemical risk assessments. This needs to be ensured through appropriate routines by personnel with the right expertise about chemical risks in the work environment. It must also be ensured that some factors, as way of working, the work environment and measures taken, need to be similar for the workplace first performing the risk assessment, and the workplace that will reuse the same risk assessment, or at least that these factors can become similar after measures taken. Some risks or obstacles of reusing chemical risk assessments have been identified. One of the most prominent risks is that chemical hazards will be missed and thereby also the measures that need to be taken. This may be due to lack of knowledge and commitment or possibly cheating or carelessness. In situations where more hazardous chemical products are being used, it may be more difficult to reuse risk assessments. Some benefits of reusing risk assessments may be less time required for chemical risk assessments, more efficient management and increased support and learning about chemical hazards by learning from each other and previous risk assessments. Possibly, reuse can also contribute to more risk assessments being carried out, thereby ensuring the safety and health of professional workers.