The use of methylchlorosilanes as an agent to produce water-repellent characteristics in cotton fabrics was patented by W.I. Patnode of the General Electric Company. Since very little information has been published on the process, this investigation was undertaken to determine the optimum conditions for treating cotton fabric. Experimental tests were made using 10 inch square samples of three different poplin type cotton fabrics dried to constant weight in a vacuum dryer and over P₂O₅ in a desiccator. Each cotton sample was treated with one of five different organo chlorosilanes or a mixture of methyltrichlorosilane and dimethyldichlorosilane. The time of contact between the fabric and silane was established at 60 seconds by a number of preliminary tests. Room temperature of approximately 30°C and pressure of approximately 710 mm were arbitrarily chosen for the reaction. The tests were made with the fabric in a three liter distilling apparatus and the required amount of silane for the volume concentration desired was vaporized and transported into the reactor by a difference in pressure of the vaporizer and reaction vessel. Fabric samples were supported in the reactor over a glass distributor ring which disbursed the silane. Volume concentrations of silanes of 0.1, 0.5, 1.0, and 5.0 percent were used in the investigation. Neutralization of end products was attempted with a 10 minute dried-air wash, 13-16 percent volume concentration of ammonia and five percent solution of sodium acetate. Data on results of tests on end products indicated the following conclusions: 1. Neutralization of end products is necessary to prevent deterioration of the fabric, as indicated by a maximum reduction in tensile strength of 80 percent as compared to an untreated sample. 2. The 60 second time of silane-fabric contact is sufficient to produce a water-repellent fabric. 3. Fabrics treated with a one percent volume concentration of mixtures of methyltrichlorosilane and dimethyldichlorosilane show a spray test rating of 90 as compared to a rating of 70-80 for fabrics treated with individual silanes. 4. Standard methods of testing treated fabrics do not indicate the hygienic properties of the treated fabrics. / Master of Science

Les façades des nouveaux bâtiments et des bâtiments existants sont altérées par la pénétration de l'eau. Afin de protéger les bâtiments et surfaces exposées aux intempéries, des traitements contenant des agents hydrophobes doivent être appliqués.<p>Les traitements utilisés à l’heure actuelle sont des traitements de surface qui se dégradent au cours du temps. L'agent hydrophobe, présent en surface, est soumis à des conditions très rudes telles que des rayonnements ultraviolets, de grandes variations de température, de l'abrasion .qui réduisent l’efficacité et la durabilité des traitements. La plupart des traitements aujourd'hui disponibles, fournisse une barrière efficace au passage de l’eau à court terme, mais doivent donc être réappliqués régulièrement. <p>Le projet de recherche, présenté ici, traite de la mise en place d'un traitement de masse de matériaux cimentaires utilisés dans la protection de structures (joints, crépi .). Ce traitement devrait offrir une protection à long terme, mais ne devrait pas modifier de manière significative les propriétés mécaniques des matériaux. <p>Les avantages d'un traitement de masse sont évidents. Seule une petite partie de l'agent hydrophobe est exposée et dégradée par les conditions climatiques et l'abrasion de surface ne porte pas atteinte à l'intégrité du traitement.<p>Une étude fondamentale a été menée afin d'étudier l'influence de l'incorporation d´agents à base de silicium sur les processus d'hydratation des ciments Portland et de comprendre leur mode d'action. Deux agents (alpha,omega dihydroxypolydimethylsiloxane et n-octyltriethoxysilane) et deux ciments Portland (ordinaire et blanc CEM I 42,5N) ont été choisis et étudiés. Trois modes d´introduction (liquides purs, émulsions et granules) ont été mis en œuvre et comparés. <p>Le but est de déterminer les meilleures conditions pour obtenir un traitement efficace et durable tout en préservant les propriétés mécaniques. Les résultats d'absorption d'eau par capillarité et de perméabilité à la vapeur d’eau sont prometteurs et les essais mécaniques sur mortiers n’ont pas montré de diminutions significatives des résistances mécaniques. <p><p>La microstructure et la progression de l'hydratation des matrices cimentaires adjuvantées et de référence, ont été caractérisées par calorimétrie à conduction, par calorimétrie différentielle à balayage couplée à la thermogravimétrie, par spectroscopie infra-rouge, par diffraction des rayons X, par porosimétrie au mercure, et par microscopie électronique à balayage.<p><p>La durabilité des matériaux adjuvantés a été étudiée afin de montrer la pertinence des traitements ainsi que l'évaluation de la progression de l'hydratation. Les performances hydrofuges ainsi que l’évolution de la microstructure, à l’issue des différents vieillissements artificiels et naturels, ont été déterminées.<p>Les mortiers mis en œuvre ont été soumis à des vieillissements artificiels simulant des conditions proches de celles rencontrées en pratique (tels que des cycles rayonnements UV, pluie, sel, gel/dégel…). Une amélioration de la durabilité des mortiers adjuvantés a été observée. Les résultats sont très encourageants et confirment l'intérêt d’un tel traitement dans la masse.<p><p>/Protection of cement-based materials means above all, moisture protection because water is primarily responsible for inducing damaging physical and chemical processes in building materials. In most cases, water repellents are applied either directly during the construction or insulation process; or as a post-treatment of the exposed surfaces in order to protect the buildings from further decay. A new way is to develop a bulk treatment for cement-based materials which should provide a long term protection without modifying the mechanical properties of the cementitious materials. <p>The advantages of a bulk treatment are obvious i.e. only a small part of the hydrophobic agent is exposed and degraded by the UV. In addition, surface abrasion does not affect the integrity of the treatment. <p><p>A fundamental study was initiated to investigate the influence of the incorporation of two active silicon-based agents (already used as post-building treatments) on the hydration processes of Portland cements and to understand the involved mechanisms of interaction. <p>Two agents (alpha,omega dihydroxypolydimethylsiloxane and n-octyltriethoxysilane) and two Portland cements (Ordinary and White Portland Cement CEM I 42,5N) were chosen and studied. Three incorporation modes (pure liquids, water emulsions and granules) were investigated. The effects of the three modes were compared.<p>The aim was to determine the best conditions for an efficient and sustainable treatment preserving the mechanical properties of the materials. <p>The results of capillary water penetration and water vapor permeability are promising and are not accompanied by a significant decrease of the mechanical performances<p><p>The microstructure and progression of hydration of admixtured cement pastes were characterized by conduction calorimetry, differential scanning calorimetry, thermo-gravimetry, infra-red spectroscopy, X-ray diffraction, mercury intrusion porosimetry, and scanning electron microscopy. <p>In addition, the durability of water-repellent additives and of the admixtured cement was studied in order to show the relevance of the treatments as well as the assessment of the progression of hydration and the type of products that were developed. <p>Mortar specimens were submitted to artificial ageing cycles such as freeze-thaw cycles, ultraviolet cycles and rain-sun cycles. <p>The general trend is an improvement of the durability of admixtured mortars. <p>The results are very encouraging and confirm the interest of the bulk mortar treatment. <p><p> / Doctorat en Sciences de l'ingénieur / info:eu-repo/semantics/nonPublished

”Durable water repellents (DWR) är textilimpregneringar som bidrar med vattenavvisande egenskaper som håller länge på funktionella tyg. Tyvärr är dessa hydrofobiska ytbehandlingar vanligtvis en källa till skadliga och persistenta kemikalier och de även är producerade från fossilbaserade resurser. Eftersom medvetenheten kring de här problemen har ökat, har innovativa, miljövänliga och biologiskt nedbrytbara alternativ tagits fram. Hittills finns dock inga produkter gjorda av 100% förnybara råvaror. I ett försök att utveckla en biobaserad, icke-giftig DWR som aktiveras under milda förhållanden, lades fokus på utveckling av en lagringsstabil sprayimpregneringsprodukt för hemmabruk. Vid formulering av emulsionerna/dispersionerna utvärderades en stor mängd biobaserade och kommersiellt tillgängliga hydrofobiska och amfifila molekyler med avseende den vattenavvisande effekt som de bidrog med på den behandlade textilen. Samtidigt bedömdes de producerade formuleringarna noggrant för att skapa förståelse om effekterna från ingredienserna och deras relation till produktens stabilitet. De kandidatprodukter som valdes ut och undersöktes vidare hade lovande vattenavvisande egenskaper och visade rimlig hållbarhetstid på åtminstone en månad i 40 °C. Standardiserade sprayscores på 3 (där 1 är sämst och 5 är bäst) nåddes efter 24 timmars hängtorkning i rumstemperatur. Dessutom uppnåddes sprayscore på 5 efter en kort, icke-industriell torktumling på låg temperatur och den behölls efter minst tio tvättar på syntetiska textiler. Utvalda produkter påverkade inte märkbart tygets andningsförmåga och majoriteten hade ingen influens på textilens mjukhet och färg. Förutom uppskalningsexperiment och partikelstorleksmätningar, granskades resultat med en tillämpningsstudie av formuleringarna på femton olika tygtyper. Produkternas effekter på utseende och känsla dokumenterades för de olika textilierna. Egenskaper som kontaktvinklar, sprayscores och tvättbeständighet bestämdes och jämfördes med en kommersiellt tillgänglig produkt. / Durable water repellents (DWR) are textile finishes that provide long-lasting water repelling properties to functional garments. However, these hydrophobic finishes are commonly a source of polluting and persistent chemicals and are produced from fossil resources. As a result of increasing awareness, innovation towards environmentally friendly and biodegradable alternatives has progressed, yet no 100% renewable sourced products are available. In an attempt to create a bio-based, non-toxic DWR, that is curable under mild conditions, focus was put on the development of a shelf stable spray impregnation product intended for consumer use. By formulating dispersion/emulsion systems, a wide variety of commercially available, renewable sourced amphiphilic and hydrophobic molecules were evaluated on their effect on the water repelling performance of treated textile fabrics. Simultaneously, the produced systems were assessed carefully to create understanding on the effect of substances and their corresponding ratios on the stability. Promising candidate products that were selected for further investigation showed reasonable stability for 1 month at 40 °C. Industrial standard spray ratings of 3 (where 1 is worst and 5 is best) after hang drying at room temperature could be reached within 24 hours. On top of that, spray ratings of 5 could be reached after short time, non-industrial tumble drying at low temperatures, which could even be retained for at least ten laundering cycles on synthetic textiles. The selected finishes did not have a measurable effect on the breathability of the treated fabrics, while the majority did not considerably affect the hands-feeling or colour of the textiles. Besides several scaling up experiments and particle size measurements, extrapolation of the findings was carried out by testing the developed formulations on fifteen different types of textiles. Effects on appearance and feel were documented, additionally, contact angle, spray score, and wash durability were determined and compared with a commercially available product.

From the Proceedings of the 1975 Meetings of the Arizona Section - American Water Resources Assn. and the Hydrology Section - Arizona Academy of Science - April 11-12, 1975, Tempe, Arizona / Water can be supplied to many arid areas by harvesting the precipitation that falls on artificially prepared water-repellent soil catchments. The failure, in 1973, of wax-treated water harvesting catchment led to this study which indicates that the failure was due to swelling and shrinking of the treated soil which caused complete structural breakdown and loss of repellency. The laboratory freeze-thaw studies demonstrated that the smoother the plot, the less chance of freeze-thaw damage. Generally, coarser-textured soil can withstand freeze-thaw cycles better than finer-textured soils. Soil properties, other than texture, may also affect resistance to damage by freeze-thaw cycles. Increasing the repellent application rate may improve resistance to breakdown.

Varaktig vattenavvisning från engelskans Durable Water Repellents (DWR) är en kemi som appliceras på textil för att göra den motståndskraftig mot vätska. En DWR-kemi som visat sig vara till stor belastning för miljön och därför genomgått en utfasning inom industrin är fluorkarboner. Detta har lett till fluorfria alternativ och även modifierade fluorkarboner vilka det finns bristande information kring gällande risker för miljö och hälsa. I och med övergången från fluorerade DWR till de fluorfria alternativen aktualiserades frågan kring hur ”durable”, alltså motståndskraftiga mot tvätt och användning, dessa verkligen är. Detta har resulterat i ett stort utbud av konsumentprodukter för återupplivning av vattenavvisning på beklädnad i hemmamiljö. Dessa konsumentprodukter har benämnts som återimpregneringar i denna studie. Återimpregneringar kan göra att användaren förblir nöjd med beklädnaden och detta minskar i sin tur det textila avfallet. Området är outforskat och industrin vill veta mer om dessa konsumentprodukter inklusive hur det textila materialet påverkas av dem. Studien har utgått från ett kundperspektiv vid val av relevanta parametrar och på ett kreativt sätt översatt dessa till laborativa testmetoder. De parametrar som funnits med i studien har varit vattenavvisning, färgförändring, luftgenomsläpplighet samt känsla vilka har använts för analys och jämförelse mellan åtta stycken fluorfria återimpregneringar. Två etablerade appliceringstekniker, wash-in och spray-on, har undersökts på fyra olika textilier som skulle kunna representera frilufts- samt arbetskläder. Två av textilierna var av polyester och två var av polyamid. Samtliga återimpregneringar gav en ökad vattenavvisande effekt. Resultatet varierade beroende på vilket textilt material och vilken återimpregnering som användes. De övriga testmetoderna, färgförändring, luftgenomsläpplighet och böjstyvhet, visade även de liknande variationer i resultaten. Wash-in och spray-on teknikerna kunde generellt visa på statistiska skillnader. Även produkter med samma varumärke applicerade med wash-in och spray-on teknik visade skilda resultat. De laborativa testmetoderna som valts ut visade sig vara användbara verktyg för utvärdering av återimpregneringar vid textilapplicering.  Utifrån litteraturens rön och denna studies resultat har slutsatsen dragits att konsumentprodukter för återimpregnering av textil har betydande skillnader beroende av vilken DWR-kemi de består av samt textiliens konstruktion och fibersort. Det säkraste fluorfria alternativet ur miljösynpunkt tros av rapportförfattarna vara vax som klassas som en kolväteskemi, men det finns mycket kvar att utforska innan en sådan slutsats kan dras med säkerhet. Denna studie har varit ett inledande steg mot att undersöka återimpregneringar som förhoppningsvis i framtiden kan leda till ett minskat textilt avfall med minsta möjliga miljöbelastning. / The textile industry uses durable water repellents (DWR) to achieve water repellency on textiles. One of these DWR chemistries, fluorocarbons, is an environmental issue and has therefore been phased-out in the industry. This has resulted in a market where both modified fluorocarbons and fluorine-free alternatives are available and there is a lack of information about these DWR regarding health and environmental aspects. Due to the changeover from the fluorinated DWR to the non-fluorinated options, the question was raised about how durable these really are. This resulted in a wide range of do-it-yourself consumer products for the water repellency revival. These consumer products have been referred to as reimpregnations in this study. The purpose of reimpregnations is to give clothing a longer life cycle. The customer remains satisfied with the garment and this in turn reduces the textile waste. The industry wants to know more about these unexplored consumer products, including how the textile material is affected by them. A customer perspective has been the basis for selecting relevant parameters in this study, which has been creatively translated into laboratory test methods. Parameters in this study have been water repellency, color change, air permeability and fabric hand. These have been used for analysis and comparison of eight fluorine-free reimpregnations. The techniques used were wash-in and spray-on and have been investigated on four different textiles representing outdoor clothing and workwear, two made of polyester and two of polyamide. All the reimpregnations showed an increased effect in water repellency. The result varied depending on which textile material and what kind of reimpregnation that was used. The other test methods also showed variation according to these factors. Over all the wash-in and spray-on techniques showed a statistical significance. Products from the same brand applied with wash-in and spray-on techniques also showed different results. The selected laboratory test methods proved to be useful tools for evaluation of reimpregnations in textile applications. Based on the literature combined with the results from this study the conclusion has been made that reimpregnation, of textile materials, has a significant difference between DWR chemistries as well as the construction and fibre type of the textile. The safest fluorine-free option, from an environmental point of view, is believed to be wax, which is classified as a hydrocarbon chemistry, however there is much left to explore before such a conclusion can be made with certainty. This study has been an initial step towards the investigation of reimpregnations, which hopefully in the future can lead to reduced textile waste with as little environmental impact as possible.