In order to evaluate the respiratory health status of spray painters exposed to paints containing hexamethylene diisocyanates (HDI) and to obtain more insight into the relationship between occupational exposures to isocyanates and chronic obstructive airway diseases, a follow up study on 33 of an original cohort of 40 randomly selected workers was undertaken. The original investigation was conducted by the author in 1989. The subjects were studied using a standardised American Thoracic Society (ATS) approved respiratory health questionnaire, baseline pre and post shift spirometry and ambulatory peak flow monitoring. Bronchial hyperresponsiveness tests using histamine (PC20) were performed. Immunological tests including IgE, RAST (HDI), and house dust mite evaluations were also made. The subjects were stratified into exposed (n=20), partially exposed (n=5) and no longer exposed (n=7) groups. One subject was excluded from the group analysis because of his indeterminate isocyanate exposure. Warehouse assistants (n=30) in a non-exposed occupation were used as controls. The worker's compliance with safety regulations and the employers provision of safety requirements was assessed by means of a questionnaire. The environmental conditions in the workplace were measured by the evaluation of the isocyanate concentrations at the worker's breathing zone. Spray booth efficiency was measured using measurements of airflow velocities and airflow patterns within the booth. Longitudinal changes in respiratory health status was assessed by comparison with baseline data studied in 1989. The exposed group showed the largest mean cross-shift declines of 297 ml (± 83.8) in forced expiratory volume in one second (FEV1). The decline in the partially exposed group was 282 ml (± 102.7) and 54 ml (± 140) in the no longer exposed group. The results of the first study, when compared with the second study, showed a mean cross-shift decline in FEV1 of 130.5 ml. (± 203) (p=0.0002) and 297ml. (± 323) (p=0.0001) respectively. Furthermore, of the spray painters examined, 10 (25%) showed clinically significant cross-shift declines in FEV1 viz. decreases >250 ml in the first study (n=40) compared with 9 (45%) in the second study (n=33). In contrast to the HDI exposed spray painters, a closely matched control group (n=30) showed a mean cross-shift increase in FEV1 of 17.4 ml ( ± 63.04). Only 2 subjects had a diagnosis of asthma which was made in childhood and not related to occupation. The mean annual baseline decline in FEV1 was greatest in the exposed group 41.25 ml (25% showed a decline greater than >90 ml per annum). These values exceeded the predicted annual declines for both smokers and non smokers due to age. The decline in the no longer exposed group was 7.85 ml per annum. Immunological tests showed no correlation with declines in FEV1 . This study demonstrates the difficulties in correlating immunological status with clinical and lung function findings in workers exposed to HDI, as a means of predicting occupational asthma. Although measurements in cross-shift declines in FEV1 appear to be a suitable predictor of occupational asthma, in some cases it was found that the forced expiratory flow rate (FEF 25-75 %) was a more sensitive predictor of early changes in the small airways. The mean isocyanate concentration in the spray painter's breathing zone was 14.65 mg/m3 (±12.219), exceeding the current South African Occupational Exposure Limit - Control Limit (OEL-CL) of 0.07 mg/m3 for isocyanates. Fifty per cent of the subjects suffered from eye irritation and 40% had dermatitis of the hand. This was expected since none of the spray painters wore goggles or gloves. Whilst no subject had evidence of clinical asthma related to spray painting, a large proportion demonstrated significant cross- shift changes in lung function implying short- term adverse effects of exposure. In addition longitudinal declines in lung function which was worse in those who continued spray painting in the follow-up study, is of major concern. The lack of cases of clinical or occupational asthma may be due to the healthy worker effect. Recommendations include, routine spirometric lung function testing of all spray painters, the use of high volume-low pressure spray guns and the wearing of positive pressure airline masks complying with the South African Bureau of Standards (SABS) safety standard. In terms of current legislation it was further recommended that spray booths be regularly monitored, including the measurement of HDI concentrations, airflow velocities and airflow patterns within the booth and the implementation and enforcement of stricter control measures. Workers demonstrating excessive declines in both cross-shift and longitudinal spirometry, require special attention. / Thesis (M.Med.Sc.)-University of Natal, 1997.

Thesis (Ph. D.)--State University of New York at Binghamton, Department of Chemistry, 2009. / Includes bibliographical references.

Nitrogen-containing heterocyclic compounds are very important to the pharmaceutical and agrochemical industries, among others. Over the past few years, the Beauchemin group has been exploring reactivity of N-substituted isocyanates and as part of this has developed a metal-free alkene aminocarbonylation process relying on imino-isocyanates to form azomethine imines. The azomethine imines formed are interesting since they contain a cyclic β-aminocarbonyl motif. Catalysis of this reaction using basic additives allowed milder reaction conditions with electron-rich C=C bonds such as enol ethers. Efforts have also been made towards the derivatization of these azomethine imines into useful products. It was discovered that upon reduction and aromatization of azomethine imines, pyrazolones could be obtained. This is providing a novel modular approach to these compounds, which have relevance in pharmaceuticals and agrochemicals. This reactivity was extended to include imino-isothiocyanates.

En funktionsbeläggning består av ett polymert material som beläggs till en textil yta. Denna typ av beläggning används för funktionsplagg och det belagda materialet har som uppgift att skydda användaren från vatten samtidigt som den har god ånggenomsläpplighet. För att tvärbinda funktionsbeläggningen och öka dess hållfasthet appliceras ett översta skikt av polymer som kallas topcoat. En topcoat innehåller tvärbindande ämnen som till exempel isocyanater eller formaldehyd. Dessa ämnen är mycket miljö- och hälsoskadliga. Denna studie har genomförts i syfte att undersöka möjligheten till en reducering av mängden topcoat och därmed minskning av skadliga kemikalier, i en funktionsbeläggning. En mikroporös polyuretanbeläggning applicerades på en polyesterväv med valsrakling. Därefter belades två vattenbaserade topcoats innehållande olika tvärbindare: en med formaldehyd och en med isocyanater, genom luftrakling. Genom att späda den ena topcoaten med olika mängd vatten, variera lutningen av beläggningskniven och ändra knivens tryck mot väven vid beläggning utvecklades sex olika material. Väven med beläggning och olika variation av topcoat testades sedan med avseende på kvalitet. Tester av materialens vattentäthet, ånggenomsläpplighet och nöthållfasthet utfördes. Mängden applicerad topcoat undersöktes genom areaviktoch tjockleksmätning. De belagda ytorna granskades i mikroskop för att analysera eventuella variationer mellan materialen. De belagda materialen var inte vattentäta (<100 cm vattenpelare). Studien visar dock att materialet belagt med en formaldehydbaserad topcoat som spätts med 68 % vatten visar statistiskt säkerställt högre medelvärde i vattentäthetstestet, jämfört med det material som belagts på samma vis men med den ospädda varianten av samma topcoat. Resultaten från areavikts- samt tjockleksmätningen visade inte med säkerhet om vinkeln på knivens lutning eller dess tryck mot väven hade någon påverkan på mängden topcoat som belades. Alla material med de spädda varianterna av topcoat visade god ånggenomsläpplighet, vilken också förbättrades avsevärt efter tvätt samtidigt som materialens vattentäthet inte försämrades i samma skala. Detta resultat är mycket intressant då bibehållen vattentäthet i kombination med god ånggenomsläpplighet efter tvätt är en viktig egenskap för funktionsbeläggningar. Slutledningsvis visar resultaten på möjligheter i att späda topcoaten innan applicering och därigenom uppnå intressanta materialegenskaper i kombination med minskad kemikalieanvändning. Vidare undersökningar krävs dock för att säkerställa eftersträvad vattentät funktion.

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.

Thèse doctorat : Sciences de la Vie et de la Santé : Strasbourg 1 : 2006. / Titre provenant de l'écran-titre. Bibliogr. 12 p.

Isocyanates, aromatic-, aliphatic- and alkanolamines are commonly used in the industry today. Millions of workers in Europe are exposed. The most frequent health symptoms are respiratory and dermal disorder. Due to the health risk most of the compounds in this thesis are regulated by authorities and have occupational exposure limits (OELs). Consequently, reliable and robust air sampling methods are urgently needed. In this thesis dry samplers for isocyanates, aliphatic- and alkanolamines have been developed and evaluated. The isocyanate sampler is now a commercial product (ASSET EZ4-NCP Dry Sampler, Supelco). The samplers were based on a denuder with a filter in series. The denuder and filter were impregnated with di-n-butylamine for the isocyanate sampler and with sulphuric acid for the aliphatic- and alkanolamine sampler. The robustness of the dry samplers was extensively evaluated. This was performed in a climate chamber containing a controlled atmosphere of the studied compounds. New methods based on hydrophilic interaction liquid chromatography (HILIC) coupled with tandem mass spectrometry (MSMS) were developed for determination of aromatic-, aliphatic- and alkanolamines in aqueous solutions. Isocyanates were determined by reversed-phase liquid chromatography MSMS. HILIC in combination with MS is a most powerful system, and highly sensitive determinations, several orders of magnitude below the OELs, of polar compounds present in the work environment can be accomplished. The selected samplers enable sampling during short sampling times and for whole work shifts. The samplers can be stored for months before and after sampling. The performance of the samplers was unaffected by variation in temperature, humidity, flow-rate and pre- and post-sampling of ambient air. Sampling for the compounds studied is now greatly simplified, and assessment of the work environment is facilitated. / <p>At the time of the doctoral defence the following papers were unpublished and had a status as follows: Paper 1: Epub ahead of print; Papers 3-5: Manuscripts</p>

Submitted by Milena Rubi (milenarubi@ufscar.br) on 2016-11-09T14:11:31Z No. of bitstreams: 1 ROSA_Wesley_2016.pdf: 8516860 bytes, checksum: ee5a7fd54adf8975660601cc883291f2 (MD5) / Approved for entry into archive by Milena Rubi (milenarubi@ufscar.br) on 2016-11-09T14:11:44Z (GMT) No. of bitstreams: 1 ROSA_Wesley_2016.pdf: 8516860 bytes, checksum: ee5a7fd54adf8975660601cc883291f2 (MD5) / Approved for entry into archive by Milena Rubi (milenarubi@ufscar.br) on 2016-11-09T14:11:50Z (GMT) No. of bitstreams: 1 ROSA_Wesley_2016.pdf: 8516860 bytes, checksum: ee5a7fd54adf8975660601cc883291f2 (MD5) / Made available in DSpace on 2016-11-09T14:11:57Z (GMT). No. of bitstreams: 1 ROSA_Wesley_2016.pdf: 8516860 bytes, checksum: ee5a7fd54adf8975660601cc883291f2 (MD5) Previous issue date: 2016-03-28 / Não recebi financiamento / The need to obtain biomaterials in order to reduce environmental impacts has been the focus of research groups in recent years, and cellulose, a dominant component at most forms of plants is a promising resource because of its abundance. In order to improve the ability processing, the chemical modification of cellulose has been widely studied. Among the most important reactions of cellulose are: etherification, esterification, acetylation and oxidation; being cellulose acetate, viscose, nitrocellulose and cellulose ethers, the main cellulose derivatives. The chemical modification with isocyanates presents some unique properties, such as absence of by-products and chemical stability of the urethane group. In this work we were synthesized gels obtained by modified cellulose acetate (CA) with a degree of substitution (DS) 2,5 by crosslinking, with 4,4' - Diphenylmethane diisocyanate (MDI) in stoichiometry of 1:1, in homogeneous by varying the humidity and the homogenization time. For characterization were used the following techniques and tests: vibrational infrared absorption spectroscopy (Fourier Transform Spectrometer - FTIR), size exclusion Chromatography (SEC), molecular absorption spectrophotometry UV-VIS, density determining of the gels by pycnometry, determination of the coefficient swelling, determination of cross-links by Flory-Rehner theory, thermogravimetry (TG) and scanning electron microscopy (SEM). Crosslink density results showed that the gel synthesized in the absence of moisture suffered greater crosslinking with an average number of repeat units between the crosslinking points of about 1000 times lower. The potential applications of these gels were tested, by using than as stationary phase in size exclusion chromatography, having been assessed its efficiency in the fractionation and separation of natural and synthetic polymers. Results showed the effectiveness of the gel as stationary phase on separation of polymers, opening up a range of opportunities, taking into consideration the simplicity of the process and lower costs attributed to it. / A necessidade de se obter biomateriais na tentativa de reduzir impactos ambientais tem sido o foco de grupos de pesquisa nos últimos anos e, a celulose, um componente dominante na maioria das formas de plantas, é um recurso promissor devido à sua abundância. A fim de melhorar a capacidade de processamento, a modificação química da celulose tem sido amplamente estudada. Dentre as reações mais importantes da celulose estão: eterificação, esterificação, acetilação e oxidação; sendo o acetato de celulose, viscose, nitrocelulose e éteres de celulose, os principais derivados da celulose. A modificação química com isocianatos apresenta algumas propriedades únicas, como ausência de produtos secundários e estabilidade química do grupo uretano. Nesse trabalho foram sintetizados géis obtidos por meio da modificação de Acetato de Celulose (AC) com grau de substituição (GS) 2,5 através da reticulação com 4,4' - Difenilmetano Diisocianato (MDI), na estequiometria 1:1, em meio homogêneo, variando a umidade e o tempo de homogenização. Para caracterização foram utilizadas as seguintes técnicas e ensaios: espectroscopia vibracional de absorção no infravermelho por Transformada de Fourier (FTIR), cromatografia de exclusão por tamanho (SEC), espectrofotometria de absorção molecular UV-VIS, determinação de densidade dos géis por picnometria, determinação do coeficiente de intumescimento, determinação de ligações cruzadas pela teoria de Flory-Rehner, termogravimetria (TG) e microscopia eletrônica de varredura (MEV). Resultados da densidade de ligações cruzadas mostraram que o gel sintetizado na ausência de umidade sofreu uma maior reticulação, com um número médio de unidades de repetição entre os pontos de reticulação cerca de 1000 vezes menor. As aplicações potenciais desses géis foram testadas como fase estacionária em cromatografia de exclusão por tamanho, tendo sido avaliada sua eficiência no fracionamento e separação de polímeros naturais e sintéticos. Resultados mostraram a eficácia do gel como fase estacionária na separação de polímeros, abrindo uma gama de oportunidades, levando-se em consideração a simplicidade do processo e os baixos custos a ele atribuídos.

La poudre de polyuréthane à base de déchets de mousse de polyuréthane a des capacités de liant classique sous certaines conditions. Ceci est très intéressant du point de vue écologique car cela permet de rallonger le cycle de vie du polyuréthane et d’économiser le premier substituant de la colle classique qui est produit à partir de 100% de matière première. Le but de cette étude était d’améliorer l’application de la poudre de polyuréthane, comme substituant de la colle pMDI, dans la production des panneaux OSB. Une importante partie de ce travail était de mieux comprendre la réactivation de la poudre de polyuréthane et les conditions nécessaires pour que la poudre puisse fonctionner de façon optimale. Des résultats de recherche ont montré que l’uréthane est dégradé à une température de 165°C en groupements d’isocyanate et de polyols. La formation d’isocyanate à pu être démontrée par plusieurs méthodes. Le savoir a été généré dans des laboratoires et confirmé avec des essais pratiques sur des lignes industrielles. Un des objectifs principaux de ce travail était de baisser la température de décomposition de la poudre de polyuréthane à un niveau suffisamment bas pour que la poudre puisse être utilisée non seulement dans les couches externes mais aussi dans la couche médiane du panneau. Dans la première phase de ce travail la poudre de polyuréthane sans additifs a été analysée. Ensuite une sélection entre différents catalyseurs utilisés dans la production de mousse de polyuréthane a été effectuée. Pour pouvoir quantifier la capacité du catalyseur une machine permettant de produire des disques à base de polyuréthane pur a été développée. Cette machine a fourni la base pour pouvoir sélectionner le catalyseur le plus performant. Ainsi cette machine donne à l’entreprise Mobius Technologies une très bonne et simple solution pour déterminer les propriétés de la poudre de polyuréthane traitée ou non traitée et pour en déterminer la qualité. Enfin, les résultats de la recherche ont pu être mis en application à l’échelle industrielle sur des lignes industrielles d’OSB chez les entreprises Kronoply, Kronofrance et chez un producteur d’outre-mer qui reste anonyme dans ce document pour des raisons de discrétion liée à l’entreprise Mobius Technologies. Il a été possible de baisser la température de décomposition de la poudre jusqu’à 147°C, grâce au catalyseur employé. L’objectif de 120°C comme température de décomposition n’a donc pas été atteint / The polyurethane powder based on recycled material or polyurethane slab stocks shows bonding properties under certain circumstances. This is interesting from the ecological point of view, because the product life cycle of the polyurethane is prolonged. In addition to that the powder can be used as substitute for standard adhesives which are produced on 100% non renewable recourses. The goal of this project was the improvement of the application of polyurethane powder, as substitute of pMDI-adhesives, which are used in the production of OSB boards. One mayor aspect of the study was the understanding of the reactivation of the polyurethane powder and to find out the conditions for an optimized use of the powder. The results of the research demonstrated that at the degradation temperature of about 165°C the urethane bond is decomposed in to isocyanates and polyols, which is already well known in polyurethane chemistry. The reverse reaction to polyurethanes could be proved by several methods. This was than in lab scale and also under industrial conditions. The main objective of the present study was to lower the activation temperature of the polyurethane powder as pMDI adhesive substitute in the core and the surface layer of wood based panels. In the start-up phase the polyurethane powder was used an analysed without any additives. Later on a selection of different typical polyurethane catalysts were used. To quantify the efficiency of different catalysts a special machine was constructed. This new developed machine provided us with the results to select the most performing catalyst. In addition this machine was used as an easy and efficient quality control tool of Mobius Technologies. The results were used to apply the polyurethane powder on industrial production units of Kronoply (Germany), Kronofrance (France) and unstated OSB-producer in overseas. It was possible to lower the activation temperature by the use of a catalyst to about 147°C. The ambitious intent to reach a temperature of 120°C was not achieved

Este trabalho teve como objetivo estudar o processo de plasticização do amido via mistura física e por reação química para a produção de novos materiais. A plasticização via mistura física foi realizada empregando-se como agentes plasticização diferentes compostos hidroxilados. Os amidos termoplásticos (TPS) foram processadas em misturador intensivo a 150°C, a partir de misturas contendo de 15 a 40% de agente plasticizante. A plasticização via reação química foi realizada com isocianatos monofuncionais e difuncionais, os quais levaram a obtenção de produtos de enxertia e entrecruzamento, respectivamente. Os produtos obtidos foram caracterizados por difração de Raios X, Calorimetria Exploratória Diferencial (DSC), Termogravimetria (TG), Análise Dinâmico-Mecânica (DMA), Microscopia Eletrônica de Varredura (SEM) e Cromatografia de Permeação em Gel (HPSEC). O estudo dos diferentes plasticizantes propiciou a determinação das características que estas substâncias devem possuir para a preparação de amidos termoplásticos. O cisalhamento desenvolvido durante o processamento em misturador intensivo levou à perda da estrutura cristalina e à desestruturação dos grânulos de amido. O processamento do TPS em misturador intensivo não provoca mudanças significativas na massa molar do amido termoplasticizado. Os amidos termoplasticizados com sorbitol foram aqueles que apresentaram menores valores de absorção de água. Os valores de módulo de Young das amostras plasticizadas com propilenoglicol aumentaram com o aumento do conteúdo de plasticizante. Para as amostras plasticizadas com etilenoglicol o módulo aumenta até 30% de conteúdo de plasticizante, quando ocorre uma diminuição do valor do módulo. Os TPS plasticizados com propilenoglicol, 1, 4-butanodiol, sorbitol e dietilenoglicol apresentaram um aumento da temperatura de transição vítrea com o aumento do tero de plasticizante. Os diferentes TPS obtidos via mistura física apresentaram estabilidade térmica similares à exibida pelo amido in natura. As propriedades mecânicas destes materiais variaram de acordo com o tipo e a quantidade de plasticizante empregado. A análise dos produtos obtidos via reação química (amidos enxertados e entrecruzados) revelou que estas reações promoveram a desestruturação dos grânulos de amido e, independentemente do regente empregado, a modificação produziu derivados mais hidrofóbicos que o amido in natura. A reação do amido com o oligômero de poli-óxido de propileno tolueno di-isocianato permitiu a obtenção de um derivado com propriedades de material elastomérico e elevada capacidade de intumescimento. Os derivados enxertados ou entrecruzados apresentaram perda de cristalinidade, redução do caráter hidrofílico e estabilidades térmicas semelhantes à apresentada pelo amido in natura. / This main of this work was to study of the cornstarch granules plasticization by means of physical or chemical treatments in order to prepare new materials. The plasticization by physical processing was performed in an intensive mixer at 150°C using ditferent hydroxylated compounds as plasticizers. The production of thermoplastic starch (TPS) by chemical reaction was carried out using mono and di-isocyanates to obtain grafted and cross linked derivatives, respectively. All the products were characterized by X Ray Diffraction, Ditferential Scanning Calorimetry (DSC), Thermogravimetry (TG), Dynamical Mechanical Analysis (DMA), Scanning Electron Microscopy (SEM), High Pressure Size Exclusion Chromatography (HPSEC). The utilization of ditferent plasticizer permitted determining which characteristics the substances must present to be used in the TPS preparation. The shear developed in the processing step lead to the loss of crystalline pattern and disruption of the starch granules. The utilization of intensive mixer does not produce significant changes in the molar mass of the thermoplastic starch. TPS produced using sorbitol as plasticizer presented the lowest level of water uptake. The valous of Young modulus for TPS produced with propylene glycol increased with the content of plasticizer. To samples produced with ethylene glycol the values of Young modulus increased until 30% and after the modulus decrease. TPS prepared with propylene glycol, 1, 4-butanediol, sorbitol and diethyleneglycol showed an increase in the glass transition temperature with the increase in the plasticizer content. The ditferent TPS produced by physical mixture shoed thermal stabilities similar to the one exhibited by in natura starch. The mechanical properties of these materials were dependent of the type and amount of plasticizer. The analysis of the derivatives obtained by chemical reaction (grafted and cross linked) revealed the occurrence of disruption of the starch granules and, independent1y of isocyanate, the products presented higher hydrophobic character than that one presented by in natura starch. By reaction starch with propylene toluene polyoxide oligomer, it was obtained a derivative with elastomeric properties and high swelling capability. The grafted or cross linked derivatives showed loss of crystallinity, decrease in hydrophilic character, and thermal stability similar to the one exhibited by in natura starch.