Stockholms stad är examensarbetets uppdragsgivare i ett samarbete mellan Exploateringskontoret, Kemikaliecentrum och Trafikkontoret. Studien syftar i huvudsak till att undersöka lekplatsmaterial ur miljö- och hälsoskyddssynpunkt. Åtskilliga studier visar att lekplatsmaterial kan innehålla miljö- och hälsofarliga ämnen. Barn är dessutom särskilt känsliga för exponering av kemikalier genom sitt beteende och fysiska förutsättningar. Stockholms stads miljöprogram och kemikalieplan prioriterar barns exponering för kemikalier och har utarbetat särskilda kriterier med barnfokus. För att systematiskt arbeta med kemikalieplanens mål används miljöbedömningssystemet Byggvarubedömningen. Ett huvudsyfte med studien var att granska Stockholms stads leverantörers sortiment av lekplatsmaterial i miljöbedömningssystemet och utvärdera hur väl systemet harmoniserar med stadens kemikaliekriterier för barnspecifika miljöer. En kemikaliesmart produktlista skapades också som ett resultat av analysen i Byggvarubedömningen. Leverantörernas miljö- och kemikaliearbete granskades likaså i en enkätstudie. Stadens aktörer tar hänsyn till ekonomi, säkerhet, platsanpassningar, tillgänglighet, miljökrav, drift, unik utformning och funktionskrav utöver miljö- och hälsoaspekter vid anläggning av lekplatser. Examensarbetet utreder också dessa olika aspekter och hur stadens aktörer kan resonera vid val av markbeläggning på lekplats i litteraturstudie baserad på intervjuer med byggprojektledare och landskapsarkitekter. Resultatet visar att Byggvarubedömningen till stor del uppfyller stadens kemikaliekrav utöver att produkter med SBR – gummi och ett fåtal hormonstörande ämnen inte filtreras. Produktlistan är ett positivt hjälpmedel ur det avseendet då det krävs kunskap om kemikalier och kriterier för att sortera ut de produkter som inte uppfyller kraven. Listan behöver dock uppdateras då fler bedömda produkter tillkommer kontinuerligt, vilket är en tids- och kunskapskrävande uppgift. Merparten av de deltagande leverantörerna i enkätstudien arbetar aktivt med hållbarhetsfrågor. Kemikaliekompetens och arbete med livscykelanalys var generellt låg hos leverantörer. Det är svårt att dra slutsatser om hur leverantörerna granskar sin egen leverantörskedja vad gäller produkternas kemikalieinnehåll. Litteraturgranskning och analysen i Byggvarubedömningen uppmärksammade också att EPDM - gummi som används i stället för återvunna däck kan innehålla oönskade ämnen. Gummimaterialen är komplexa och innehållsdeklareras också felaktigt och sparsamt i vissa fall. Dessvärre omfattas inte heller offentlig lekplatsutrustning av Leksaksdirektivets strängare kemikalie- och dokumentationskrav eller CE-märkning. Vid val av markbeläggning på lekplats är intressekonflikter främst relaterade till kombinationen säkerhet, tillgänglighet och miljö- och hälsoaspekter. Det finns inga formella hinder för användning av gummi som markbeläggning i staden (exkl. återvunnet gummi eller gummi som bedöms som ”Undviks” i Byggvarubedömningen). Studiens resultat visar dock att det kan finnas anledning att vara försiktig med användningen av gummi. Fallskyddsgummi kan vara befogat på ytor där kombinationen säkerhet och tillgänglighet bör uppfyllas. I övrigt tyder lekvärden, graden av fysisk aktivitet och tillgänglighetsaspekten på att gummit kan bytas ut till material som är bättre ur miljö- och hälsosynpunkt. Att undersöka alternativa material som uppfyller säkerhet, tillgänglighet och miljöaspekter är också angeläget.

In this work, EPDM rubber was compounded with increasing amount of filler (FEF N 550 type carbon black), process oil (saturated mineral oil), vulcanizing agent [di (t-butylperoxy) diisopropyl benzene, i.e., BBPIB] and diene [5-ethylidenebicyclo(2.2.1)-hept-2-ene, i.e., ENB] in order to investigate mechanical and rheological properties. Effect of Increasing amount of filler was investigated by using FEF N 550 type carbon black in 35, 70, 87.5, 105 phr. Decrease in scorch times of vulcanization reactions, ts2 (25, 21, 19, and 18 s, respectively) and slight increase in rate constants for vulcanization reactions (0.0270, 0.0274, 0.0301 and 0.0302 s-1, respectively) were explained in terms of nature of semi-active filler. Effect of increasing amount of process oil was investigated by using saturated mineral oil (TUDALEN 3909) in 15, 30, 45 phr. Scorch time for vulcanization reaction and rate constants were measured as 95, 103, 97 s and 0.0277, 0.0274, 0.0291 s-1, respectively. Effect of increasing amount of vulcanizing agent was investigated by using BBPIB (PERKADOX 14/40 MB-gr) in 2.5, 5, 7.5, 10 phr. The compound with 5 phr vulcanizing agent gave optimum rheometer data, crosslink density,, ultimate tensile strength, hardness, deflection and damping. Vulcanization reaction rate constant reached 0.0335 s-1 with 7.5 phr vulcanizing agent. Effect of increasing ENB ratio was investigated by using 4 different EPDM with ENB ratios 5.0, 5.6, 7.5, 8.9%. With two different cure systems, compounds with 5.6 and 7.5% ENB ratio gave optimum results. Vulcanization cure time, reaction rate constant and compression set properties changed in irregular manner.

Composite insulators are widely being used in power industry to alternate traditional porcelain-based insulators for their advantages, including better pollution performance, low maintenance cost, light weight, compact line design. However, due to the short application history and experience, the degradation of composite insulators in natural environment is a big concern for the power utilities. The knowledge on the degradation of composite insulators is being studied world wide. The methods to assess the working conditions of composite insulators are being studied and created. In Queensland University of Technology (QUT), the approach based on chemical analysis methods was first developed. The work in this thesis based on the previous research work is focused on correlating electrical characteristics with chemical analysis results of the composite insulators and physical observations results. First,the electrical characteristics of composite insulators were presented and analysed, including leakage current, cumulative current, peaks of leakage current, the statistic results of the leakage current. Among them, the characteristics of leakage current were mainly studied. The shape of waveforms was found to relate to the degree of discharge activities of the composite insulators. The waveforms analysed by FFT revealed that the odd harmonic components became obvious during the discharge activities. The correlations between the electrical characteristics of composite insulators and chemical analysis results showed that the composition of composite insulators plays significant roles in terms of electrical performance. The oxidation index (O.I.) and the ester/ketone ratio (E/K) differentiated the different degradation reasons of the composite insulators in the test conditions. Finally, the thesis presents one approach, which aims to assess the surface conditions of composite insulators in an easy manner and in short time.

Orientador: Maria Isabel Felisberti / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Quimica / Made available in DSpace on 2018-08-05T05:18:11Z (GMT). No. of bitstreams: 1 Hanamoto_LilianSatomi_D.pdf: 13319819 bytes, checksum: 0e6b63b39a199cc970951da7436dd7f6 (MD5) Previous issue date: 2005 / Doutorado / Físico-Química / Doutor em Ciências

Submitted by Rosa Assis (rosa_assis@yahoo.com.br) on 2017-11-13T17:12:52Z No. of bitstreams: 2 Fabíola da Silva Unzelte Caleffi.pdf: 1947526 bytes, checksum: 20fc271ba3ed6063116609a99d7642ac (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Paola Damato (repositorio@mackenzie.br) on 2017-11-21T13:46:04Z (GMT) No. of bitstreams: 2 Fabíola da Silva Unzelte Caleffi.pdf: 1947526 bytes, checksum: 20fc271ba3ed6063116609a99d7642ac (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2017-11-21T13:46:04Z (GMT). No. of bitstreams: 2 Fabíola da Silva Unzelte Caleffi.pdf: 1947526 bytes, checksum: 20fc271ba3ed6063116609a99d7642ac (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2012-02-13 / Many studies have been done looking for new applications become viable for the ash of rice husks micronized. These studies include the use of this material as a reinforcing filler in elastomeric compounds to substitute other materials, to promote better mechanical performance such as tensile strength at break, hardness, elongation, and reduce the cost. The objective of this study was to obtain and characterize the elastomeric compounds based on EPDM and carbon black as filler and different concentrations of black ash of rice husks micronized and compare their performance with elastomeric compounds based on EPDM containing only black as filler smoke. The elastomer was processed in a calender with the respective filler, processing aids, plasticizers and curing system. After processing by calendering, the elastomeric compound has been tested that includes the rheological and rheometry testing by Dynamic Mechanical Thermal Analysis (DMTA). These tests showed, respectively, the parameters of speed of healing and glass transition temperature (Tg). Subsequently the material was cured in a hydraulic press with heating. To test resistance to oil, the specimens were immersed in ASTM oil 3 to measure the percentage of swelling. Were also performed mechanical tests of compression permanent deformation (compression set), tensile strength, tear strength, resilience and hardness Shore A. Through the results, it was observed that the addition of black ash rice hulls in the compounds modifies the glass transition temperature (Tg), but practically does not change the rheology during vulcanization. Compounds containing 20% black ash of rice husks showed better mechanical properties of tensile strength, tear strength and elongation. For higher concentrations, there is only the behavior of the filler. The addition of ash from rice hulls black also increases the hardness and improved oil swelling resistance and reduces permanent deformation to compression and resiliency. / Muitos estudos têm sido realizados procurando tornar viáveis novas aplicações para as cinzas de cascas de arroz micronizadas. Estes estudos incluem a utilização deste material como carga de reforço em compostos elastoméricos em substituição a outros materiais, para promover melhor desempenho mecânico como resistência à tração, à ruptura, dureza, elongação, além de diminuir o custo. Assim, o objetivo deste trabalho foi obter e caracterizar compostos elastoméricos a base de EPDM contendo como carga negro de fumo e diferentes concentrações de cinzas pretas de cascas de arroz micronizadas e comparar o seu desempenho com compostos elastoméricos a base de EPDM contendo como carga apenas negro de fumo. O elastômero foi processado em uma calandra junto com as respectivas cargas, auxiliares de processo, plastificante e sistema de cura. Após o processamento por calandragem, o composto elastomérico foi submetido a testes reológicos que inclui a reometria e ensaios por Análise Térmica Dinâmico-Mecânica (DMTA). Esses testes mostraram, respectivamente, os parâmetros de velocidade de cura e temperatura de transição vítrea (Tg). Posteriormente, o material foi vulcanizado em prensa hidráulica, com aquecimento. Para testes de resistência ao óleo, os corpos de prova foram imersos em óleo ASTM 3 para medir a porcentagem de inchamento. Foram também realizados os ensaios mecânicos de deformação permanente à compressão (compression set), resistência à tração, resistência ao rasgamento, resiliência e dureza Shore A. Por meio dos resultados obtidos, observou-se que a adição de cinzas pretas de cascas de arroz nos compostos altera a temperatura de transição vítrea (Tg), mas praticamente não altera a reometria durante a vulcanização. Os compostos contendo 20% cinzas pretas de cascas de arroz apresentaram melhores propriedades mecânicas de resistência à tração, rasgamento e alongamento. Para concentrações maiores, há o comportamento apenas de carga de enchimento. A adição de cinzas pretas de cascas de arroz também aumenta a dureza e melhora o inchamento em óleo e diminui a resistência à deformação permanente à compressão e a resiliência.

The diploma thesis deals with the EPDM addition influence on ozone resistance of NR/SBR mixtures. The theoretical part summarizes knowledge about rubber processing, additivation and effects of ozone on vulcanized rubber. The experimental part aims on preparation of rubber blends and measurement of its mechanical, physical and rheological properties in dependance on their composition.

The steady growth of the rubber industry requires attention regarding the waste management and the methods applied in recycling and in the reclaiming processes. The ok in this thesis responds to the demand for an efficient recycle method for EPDM rubber waste. A solvent free chemical activation method to recycle EPDM rubber waste which provides high-quality recycled products, despite of the high amount of recycled particles used as a substitute of the raw material, was developed. The process needed to be both environmentally sustainable and applicable on an industrial scale without requiring special equipment. The final aim of this project was to use the activated particles in the production of seals and sealing systems on an industrial scale. In order to achieve this, the recycling of EPDM rubber waste particles by means of chemical activation using low molecular weight polymers (liquid polymers) was investigated. These liquid polymers are highly compatible with the waste rubber particles from the EPDM rubber and also suitable for sulphur vulcanisation. In comparison with other methods used for recycling of rubber and when considering environmental and economic aspects, chemical activation at the surface particle using low molecular weight polymers offers great recycling potential. In order to demonstrate the potential of the activated particles as a substitute for the raw material, aspects were investigated including: (1) characterization of the EPDM rubber waste particles; (2) optimization of the ratio between the waste rubber particles and the low molecular weight polymers; (3) investigation of the influence of various amounts of curing system; (4) study of the effect of the diene and ethylene percentage contained by the low molecular weight polymer used for activation of the particles; (5) investigation of the influence of the amount of activated particles used as substitute of the raw material; (6) study of the type of curing system used and (7) application of the process on an industrial scale.

This thesis investigates the hydrogen application of ball valves. The approach taken was that of a gap analysis where the current situation at ball valve manufacturer ERIKS is considered as a starting point and the desired situation is a ball valve for hydrogen applications. Interviews, literature and document review, and CAD modelling were techniques used to find a solution. This solution was then tested through an experimental setup according to ISO standard 15848 one missions. The valve with EPDM O-ring passed the test up to the CO3 stage successfully when the testing was stopped. Overall this proves the expectation of using the ball valve in real-world application is realistic. The drawbacks of the thesis lie in the limited analysis of sustainability and the lack of testing at various temperatures. The temperature concerns are partially remedied due to the previously gathered data on the material at these higher temperatures.

No description available.

Les élastomères à base d’Ethylène Propylène Diène Monomère (EPDM) sont utilisés dans les accessoires du réseau de distribution d’électricité sous-terrain pour assurer l’isolation des jonctions de câbles. En effet, la structure chimique de ce polymère est apolaire et induit donc l’hydrophobicité désirée pour cette application. Cependant, en conditions de service, la thermo-oxydation provoque l’incorporation d’atomes d’oxygène (formation de fonctions hydrophiles) aux chaines EPDM. Ainsi, l’objectif de cette thèse était d’étudier l’influence du vieillissement thermo-oxydant sur les propriétés de transport d’eau dans les accessoires en EPDM. Trois formulations d’EPDM sans charges (une réticulée au peroxyde et deux autres réticulées au soufre) ainsi que six formulations industrielles (toutes réticulées au soufre) ont subi un vieillissement thermique accéléré en étuve ventilée d’air entre 90 et 190°C. L’analyse multi-échelle (combinant plusieurs techniques expérimentales) a permis de mettre en évidence les modifications structurales dans les matrices EPDM et d’établir des corrélations entre les propriétés physico-chimiques mesurées au cours du vieillissement. Les propriétés de transport d’eau ont ensuite été caractérisées entre 30 et 70°C et entre 10 et 100 % HR à l’état initial et pour différents états d’oxydation. Ces résultats ont permis d’établir des relations structure/propriété entre les propriétés de transport d’eau et l’incorporation d’oxygène, mais aussi de simuler l’influence cruciale des charges. / Ethylene Propylene Diene Monomer (EPDM) based elastomers are used in the accessories of the underground electrical distribution network for guaranteeing the insulation of cable junctions. Indeed, the chemical structure of this apolar polymer gives the desired hydrophobicity for this application. However, in service conditions, thermo-oxidation causes an incorporation of oxygen atoms (formation of hydrophilic function) into EPDM chains. Thus, this PhD thesis aimed at studying the influence of thermal oxidative ageing on the water transport properties into EPDM accessories. Three unfilled formulations (one peroxide crosslinked and two sulfur vulcanized) and six industrial formulations (all vulcanized) were submitted to an accelerated thermal ageing in air-ventilated ovens between 90 and 190 °C. The multi-scale analysis (combining several experimental techniques) allowed highlighting the structural changes in EPDM matrices and establishing correlations between the physico-chemical properties measured during ageing. Then, the water transport properties were characterized between 30 and 70 °C and between 10 and 100 %RH at the initial state and for different oxidation states. These results allowed establishing structure/property relationships between water transport properties and oxygen incorporation, but also to simulate the crucial influence of fillers.