Dossier – Silicones
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Chlorotrimethylsilane
Chlorotrimethylsilane Health-based recommended occupational exposure limit Gezondheidsraad Voorzitter Health Council of the Netherlands Aan de Staatssecretaris van Sociale Zaken en Werkgelegenheid Onderwerp : Aanbieding adviezen over Chloortrimethylsilaan en Butylacetaten Uw kenmerk : DGV/MBO/U-932542 Ons kenmerk : U 2173/AvdB/tvdk/459-D35 Bijlagen : 2 Datum : 15 november 2001 Mijnheer de Staatssecretaris, Bij brief van 3 december 1993, nr. DGV/BMO-U-932542, verzocht de Staatssecretaris van Welzijn, Volksgezondheid en Cultuur namens de Minister van Sociale Zaken en Werkgelegenheid om gezondheidskundige advieswaarden af te leiden ten behoeve van de bescherming van beroepsmatig aan stoffen blootgestelde personen. Per 1 januari 1994 heeft mijn voorganger daartoe een commissie ingesteld die de werkzaamheden voortzet van de Werkgroep van Deskundigen (WGD). De WGD was een door de genoemde Minister ingestelde adviescommissie. Hierbij bied ik u - gehoord de Beraadsgroep Gezondheid en Omgeving - twee publicaties aan van de commissie over chloortrimethylsilaan en butylacetaten. Deze publicaties heb ik heden ter kennisname aan de Minister van Volksgezondheid, Welzijn en Sport en aan de Minister van Volkshuisvesting, Ruimtelijke Ordening en Milieubeheer gestuurd. Hoogachtend, w.g. prof. dr JA Knottnerus Bezoekadres Postadres Parnassusplein 5 Postbus 16052 2511 VX Den Haag 2500 BB Den Haag Telefoon (070) 340 75 20 Telefax (070) 340 75 23 Chlorotrimethylsilane Health-based recommended occupational exposure limit report of the Dutch Expert Committee on Occupational Standards, a committee of the Health Council of The Netherlands to the Minister and State Secretary of Social Affairs and Employment No. 2001/05OSH, The Hague, 15 November 2001 The Health Council of the Netherlands, established in 1902, is an independent scientific advisory body. -
The Unique Properties of Siloxanes
THE UNIQUE PROPERTIES OF SILOXANES This factsheet explains what makes siloxanes unique. Want to know how siloxanes are different from carbon-based materials? Or why they behave differently in the environment? Read on to find out more, including why the current PBT assessment criteria might not be suitable for them. WHAT ARE SILOXANES? Siloxanes are a group of substances characterized by a chain of alternating silicon (Si) and oxygen (O) atoms. Within the group, individual siloxane substances differ in size, weight and shape. They form the backbone of silicone polymers that are used in a variety of applications such as sealants, adhesives, coatings, plastics, cosmetics, medical devices, hygiene products, food contact materials, and many other industrial applications. Siloxane functional group Octamethylcyclotetrasiloxane (D4) WHAT ARE SILICONE POLYMERS? The structure and functionality of these chemical compounds drive the specific Silicones are specialty products that are used in small amounts in hundreds combination of properties of siloxanes of applications where their special performance is needed. They are used as including: adhesives, they create flow, they insulate, and they have excellent mechanical/ optical/thermal resistance among many other properties. Silicone polymers can • High propensity to repel water have very different forms depending on how they are built, for example: • Low water solubility • Volatility USED AS LUBRICANTS AND LIQUIDS/OIL IN HYDRAULIC FLUIDS Silicone materials offer a host of useful characteristics including: -
Functionalized Hybrid Silicones – Catalysis, Synthesis and Application
Technische Universität München Fakultät für Chemie Fachgebiet Molekulare Katalyse Functionalized Hybrid Silicones – Catalysis, Synthesis and Application Sophie Luise Miriam Putzien Vollständiger Abdruck der von der Fakultät für Chemie der Technischen Universität München zur Erlangung des akademischen Grades eines Doktors der Naturwissenschaften (Dr. rer. nat.) genehmigten Dissertation. Vorsitzender: Univ.-Prof. Dr. M. Schuster Prüfer der Dissertation: 1. Univ.-Prof. Dr. F. E. Kühn 2. Univ.-Prof. Dr. O.Nuyken (i.R.) Die Dissertation wurde am 16.02.2012 bei der Technischen Universität München eingereicht und durch die Fakultät für Chemie am 08.03.2012 angenommen. The following dissertation was prepared between April 2009 and March 2012 at the Chair of Inorganic Chemistry, Department of Molecular Catalysis of the Technische Universität München. I would like to express my deep gratitude to my academic supervisor Prof. Dr. Fritz E. Kühn for his support and confidence and the freedom of scientific research. This work was supported by a research grant from the BASF Construction Chemicals GmbH, Trostberg, Germany. Acknowledgement I would like to express my sincere gratitude to Prof. Dr. Oskar Nuyken and Dr. Eckhart Louis for their ongoing support and their undamped enthusiasm for my research topic. They supported this work with many inspiring discussions, new ideas and critical questions. I thank the BASF Construction Chemicals GmbH, Trostberg, for giving me the opportunity to work on an industrial cooperation project. Especially, I would like to thank Dr. Simone Klapdohr and Dr. Burkhard Walther, who accompanied this project from the industrial perspectice, for their support and the nice time I had in Trostberg during the application technological tests. -
Environmental Risk Assessment Report: Decamethylcyclopentasiloxane
Environmental Risk Assessment Report: Decamethylcyclopentasiloxane Science Report Environmental Risk Assessment: Decamethylcyclopentasiloxane 1 The Environment Agency is the leading public body protecting and improving the environment in England and Wales. It’s our job to make sure that air, land and water are looked after by everyone in today’s society, so that tomorrow’s generations inherit a cleaner, healthier world. Our work includes tackling flooding and pollution incidents, reducing industry’s impacts on the environment, cleaning up rivers, coastal waters and contaminated land, and improving wildlife habitats. Published by: Author(s): Environment Agency, Rio House, Waterside Drive, Aztec West, Brooke D N, Crookes M J , Gray D and Robertson S Almondsbury, Bristol, BS32 4UD Tel: 01454 624400 Fax: 01454 624409 Dissemination Status: www.environment-agency.gov.uk Publicly available / released to all regions ISBN: 978-1-84911-029-7 Keywords: © Environment Agency April 2009 Decamethylcyclosiloxane, siloxane All rights reserved. This document may be reproduced with prior Research Contractor: permission of the Environment Agency. Building Research Establishment Ltd, Bucknalls Lane, Garston, Watford, WD25 9XX. Tel. 01923 664000 The views expressed in this document are not necessarily those of the Environment Agency. Environment Agency’s Project Manager: Steve Robertson, Chemicals Assessment Unit, Red Kite House, This report is printed on Cyclus Print, a 100 per cent recycled Howbery Park, Wallingford OX10 8BD. Tel 01491 828555 stock, which is 100 per cent post consumer waste and is totally chlorine free. Water used is treated and in most cases returned Collaborator(s): to source in better condition than removed. D Gray, Health and Safety Executive Further copies of this report are available from: Product code: The Environment Agency’s National Customer Contact Centre SCHO0309BPQX-E-P by emailing [email protected] or by telephoning 08708 506506. -
Silicone Elastomers with Exceptional Elongation ACS Rubber
Silicone Elastomers with Exceptional Elongation Barry Arkles*, Jonathan Goff, Santy Sulaiman Gelest Inc. 11 East Steel Rd. Morrisville, PA 19067 Presented at the 188th Technical Meeting of Rubber Division, ACS / International Elastomer Conference Paper # 124 October 12-15, 2015 Cleveland, OH *Speaker 1 ABSTRACT Polysiloxanes elastomers formed by the step-growth of heterobifunctional macromers achieve high molecular weights and show elastomeric behavior. There is no apparent mechanism for crosslinking and advanced NMR and DSC techniques as well as rheological studies support the fact that, within the limits of detection, the step-growth elastomers are linear. When formed into nanocomposites by the incorporation of surface passivated fumed silica, they exhibit elongations exceeding 5000%. At extensions comparable to conventional silicone elastomers, they show similar elastic recovery. At greater extensions, recovery is reduced marginally. These materials are readily manufacturable and can be compounded and processed similar to conventional two-component platinum cure silicone RTVs. We have adopted the designation of xPDMS for these materials, a modified acronym for “high eXtension PolyDiMethylSiloxanes”. The synthesis, characterization, and mechanical properties of the first example of of an xPDMS suitable for commercial production is presented. INTRODUCTION In most commercial applications, single component silicone elastomers are conventionally prepared by either the crosslinking of a polysiloxane component in a silica reinforced base by a peroxide (HCR, high consistency rubber) or by a moisture-cure mechanism (condensation RTVs, room temperature vulcanizates)1. Another more flexible approach for commercial fabrication of silicone elastomers is to use two polysiloxane components in which 2 one polysiloxane component is generally of higher molecular weight and can be thought of the matrix polymer, and the second polysiloxane component, which is generally of lower molecular weight and can be thought of as a crosslinker. -
Advances in the Understanding of Low Molecular Weight Silicon Formation and Implications for Control by Amc Filters
APPLICATION NOTE ADVANCES IN THE UNDERSTANDING OF LOW MOLECULAR WEIGHT SILICON FORMATION AND IMPLICATIONS FOR CONTROL BY AMC FILTERS Authors: Jürgen M. Lobert, Philip W. Cate, David J. Ruede, Joseph R. Wildgoose, Charles M. Miller and John C. Gaudreau Abstract Introduction Trimethylsilanol (TMS) is a low molecular Silicon containing hydrocarbons are a class of weight / low boiling point silicon-containing, AMC causing persistent degradation of UV exposure airborne contaminant that has received increased tool optical surfaces.1,2,3 Organic silicon compounds interest over the past few years as an important are efficiently split into components by 193 nm UV cause for contamination of optical surfaces in light, commonly used in photolithography appli- lithography equipment. cations. The resulting, reactive silicon atoms can recombine with oxygen to create a layer of amor- TMS is not captured well by carbon-based filters, phous silicon dioxide on optical surfaces such as and hexamethyldisiloxane (HMDSO), even though exposure tool lenses.3,4 This haze layer can be captured well, can be converted to TMS when using difficult to remove and may require lens exchange acidic filter media commonly used for ammonia and polishing, potentially destroying optical coatings removal. TMS and HMDSO coexist in a chemical and creating substantial tool downtime and cost. equilibrium, which is affected by the acidity and The importance of TMS and related refractory moisture of their environment. species in optical degradation is one reason for This publication shows that HMDSO is converted the low level of allowable refractory compounds to TMS by acidic media at concentrations typically (100 ppt) specified in the International Technology found in cleanroom environments. -
Mechanical and Electrical Studies of Silicone Modified Polyurethane
Polymer Journal, Vol. 36, No. 10, pp. 848—855 (2004) Mechanical and Electrical Studies of Silicone Modified Polyurethane–Epoxy Intercrosslinked Networks y Arun ANAND PRABU and Muthukaruppan ALAGAR Department of Chemical Engineering, Anna University, Chennai-600 025, India (Received May 27, 2004; Accepted July 20, 2004; Published October 15, 2004) ABSTRACT: A series of intercrosslinked networks (ICNs) based on silicone modified polyurethane (PU)–epoxy resins were developed. In this study, epoxy resin (diglycidyl ether of bisphenol-A) was modified with PU prepolymer and hydroxyl-terminated polydimethylsiloxane (HTPDMS) using -aminopropyl triethoxysilane ( -APS) as silane cross linker and dibutyltindilaurate (DBTL) as catalyst to form ICNs. Aromatic polyamine adduct (A), diethylenetri- amine (B) and polyamidoamine (C) were used as epoxy curatives. The final products were obtained in the form of tough films. Changes in chemical structure during ICN formation, mechanical and electrical properties were investigated us- ing FT-IR spectra, tensile, impact and dielectric testing. The mechanical properties were enhanced with incorporation of PU (10 wt %) and silicone (10 wt %) due to the toughening of brittle epoxy matrices. Electrical properties showed a marginally decreasing trend with the incorporation of PU (0–20 wt %) influenced by the polar urethane linkages where- as silicone incorporation (10 wt %) showed an enhancement due to the presence of inorganic –Si–O–Si– linkage. Among the systems studied, the silicone (10 wt %) modified PU (10 wt %)–epoxy cured with ‘‘A’’ exhibited excellent mechanical and electrical characteristics and can be used as coatings and composites for industrial, electrical and ma- rine components. [DOI 10.1295/polymj.36.848] KEY WORDS Intercrosslinked Network / Epoxy / Polyurethane / Silicone / Coatings / Composites / Numerous polymeric resins based on epoxy, unsat- used in epoxy and polyurethane synthesis. -
Innovative Silicone Solutions
Toronto Head Office, Research Lab and Plant Mississauga, Ontario, Canada Plant Siltech Corporation Siltech LLC (Personal Care Applications) 225 Wicksteed Avenue 1625 Lakes Parkway . Suite O Toronto . Ontario . Canada Lawrenceville . GA . USA M4H 1G5 30043 Telephone: 416.424.4567 Telephone: 678.442.0210 Facsimile: 416.424.3158 Facsimile: 678.442.9624 www.siltech.com ISO 9001:2008 Registered Aug/2016 INNOVATIVE SILICONE SOLUTIONS 14 Silicon : The 14th element in the periodic table; chemical symbol; Si, density = 2.33g/ml; molar mass = 28.09 g/mol; melting point = 1,420°C; boiling point = 3,265°C; electronic 2 2 Siltech is a privately owned business, managed and operated by the owners for more than 20 years. configuration [Ne]3s p ; metallic-looking; does not occur naturally in free form; in its combined We hope and believe that the pride we feel in this company channels its way through each of our form, accounts for 27.6% of the Earth’s crust; 2nd most abundant element on Earth after oxygen employees and to every customer. and one of the 10 most abundant elements in the solar system - 4.47 x 10 7 (rel. to [H] = 1 x 10 12). Siltech is a place where someone answers the phone when you call. It is a place where we feel passion about the quality of our products and realize that our livelihood depends on satisfying you, our customer. And it is a place where you can source products with confidence. Siltech develops and manufactures a full line of organo-functional silicone compounds and related specialties for a wide range of industrial and personal care applications, using our patented and otherwise proprietary technologies. -
Basic Silicone Chemistry – a Review
Editors Note: This edition of the Silicone Spectator is presenting a general article on Silicone Chemistry written in 1999. While the paper was written a long while ago the contents are still topical today. We hope you enjoy. Basic Silicone Chemistry – A Review Anthony J. O’Lenick, Jr. Siltech LLC Dacula, Ga. 30019 First Published: August 1999 This review has been written with the objective of supplying a working knowledge of the chemistry of silicone compounds to the practicing chemist. It has been divided into two parts, the first dealing with basic chemistry of silicones, and the second dealing with silicone based surfactants. Despite the fact that silicone compounds have been around for over fifty years, the chemistry of these materials remains elusive to the average formulating chemist. This is indeed unfortunate, since the chemistry of silicon atom and resulting silicone compounds is every bit as wide in scope and rich in content as the chemistry of the carbon atom and the resulting surfactant chemistry upon which it is based. Whilst the chemistry upon which surfactants are commonly based has been around for almost exactly the same period as that of the basic silicone chemistry, it is only in the past decade that the ability to use silicone as a hydrophobic material in the preparation of surfactants has been common. The recent trend to combine silicone, fatty and polyoxyalkylene moieties in the same molecule has resulted in a plethora of new compounds with new properties. Introduction Silicon is the 14th element in the periodic table. Although it does not occur naturally in free form, in its combined form it accounts for about 25% of the earth's crust. -
(Quartz) Silica, Sio2, Is a White Or Colorless Crystalline Compound
Silica (quartz) Silica, SiO2, is a white or colorless crystalline compound found mainly as quartz, sand, flint, and many other minerals. Silica is an important ingredient to manufacture a wide variety of materials. Quartz; Quartz is the most abundant silica mineral. Pure Quartz is colorless and transparent. It occurs in most igneous and practically all metamorphic and sedimentary rocks. It is used as a component of numerous industrial materials. Silicon (Si) has the atomic number 14 and is closely related to carbon. It is a relatively inert metalloid. Silicon is often used for microchips, glass, cement, and pottery. Silica is the most abundant mineral found in the crust of the earth. One of the most common uses of silica quarts is the manufacturer of glass. Silica is the fourteenth element on the periodic table. It can sometimes be found as the substance, quartz which is usually used in jewelry, test tubes, and when placed under pressure, generates an electrical charge. Quartz is the second most abundant mineral in the Earth's crust. It is a clear, glossy mineral with a hardness of 7 on the MOHS scale. Silica, Sa,is a component of glass and concrete. A form of Silica commonly known as quartz, Silica tetrahedra, is the second most common mineral in the earth's crust, it comes in many different forms. Silica is a compound of silicon and oxygen. Earth's outer crust contains 59% of this material. It has three major rock forms, which are quartz, tridymite, and cristobalite. Silica, commonly known in the form of quartz, is the dioxide form of silicon, SiO2. -
Synthesis of Pendant Epoxy Functional Polydimethyl Siloxane for Modification of Diglycidyl Ether of Bis-Phenol A
Available online at http://www.urpjournals.com Advances in Polymer Science and Technology: An International Journal Universal Research Publications. All rights reserved Original Article Synthesis of pendant epoxy functional polydimethyl siloxane for modification of Diglycidyl Ether of Bis-phenol A Jenish Paul1, 2, A. Benny Cherian2, K.P.Unnikrishnan2 and Eby Thomas Thachil1 1- Polymer Science &Rubber Technology, Cochin university of science & Technology,Kochi- 22 2- Chemistry Department, Union Christian College, Aluva-5 Received 22 December 2011; accepted 30 December 2011 Abstract In this study, pendant epoxy functional poly dimethyl siloxanes were synthesized by the hydrosilylation reaction of pendant silyl hydride functional polydimethyl siloxane with allyl glycidyl ether. The hydrosilylation reaction was characterized by spectroscopic techniques. Samples of pendant epoxy functional poly dimethyl siloxanes and pendant silyl hydride functional polydimethyl siloxane were blended with commercial epoxy resin, diglycidyl ether of bis-phenol A, at various ratios using a polyamine as curing agent. The results show that the addition of functionalised poly dimethyl siloxanes increases the flexibility of the cross linked network and also the thermal stability and water resistance. © 2011 Universal Research Publications. All rights reserved Key words: DGEBA; resin; polysiloxanes; hydrosilylation; blending. 1. Introduction functionalise them. One of the major processes used to Epoxy resin exhibits many desirable properties, such as functionalize polysiloxanes is hydrosilylation of high strength and modulus, excellent chemical and solvent polyhydridosiloxanes [12]. resistance, good thermal and electrical properties and 1.2. Hydrosilylation outstanding adhesion to various substrates, and easy process Hydrosilanes react with compound containing carbon- ability under various conditions [1-5]. Epoxy resins are also carbon multiple bonds when catalyzed by transition metal widely used as molding compounds and encapsulation of complexes. -
Silicone Rubber Science
Silicone Guide Power Chemical Corporation Limited Silicone Rubber Power Chemical Corporation Limited Silicone Rubber Quality & lower price is our commitment. Background Structure and Chemistry Silanes Siloxanes Classes of Silicone Rubbers Industrial Classifications Synthesis of Silicones Other Components in Silicones Curing Additives Fillers Other Additives Manufacture Liquid Silicone Rubbers Room Temperature Vulcanising (RTV) Rubbers Key Properties Advantages Disadvantages Thermal Stability Flexibility Resistance to Hydrocarbons, Oils and Solvents Gas Permeability Electrical Properties Applications Mechanical Engineering Electrical Engineering Medical - 2 - ©2011 Power Chemical Corporation Limited. SiSiB® is a registered trademark of PCC. www.PCC.asia www.SiSiB.com Power Chemical Fax: +86-25-8468-0091 Tel: +86-25-8468-0092 ISO9001 ISO14001 certificated June 2011 Silicone Rubber Quality & lower price is our commitment. Background Dumas predicted the existence of silicone rubbers ion 1840. However, it was not until 1872, that Ladenburg produced the first example, a very viscous oil, by reacting diethoxydiethysilane with water and trace amounts of acids. The first commercial grades were produced in 1943 by the Dow Chemical Company, with many other companies following shortly after. Back Structure and Chemistry Silanes Silanes are analogous to hydrocarbons, i.e, the basic building block of hydrocarbons is the CH4 (methane) group, while that for silianes is SiH4 (silane) and the basic structure is SiH3(SiH2)nSiH3. These materials have the Si-Si-Si backbone and the resultant structures are named based on the number of silicon atoms in the chain i.e. silane, disilane, trisilane, tetrasilane etc etc. Furthermore, similar substitutions can take place, as is the case with hydrocarbons, e.g.