DOCSLIB.ORG

Emergence and Fate of Siloxanes in Waste Streams: Release Mechanisms, Partitioning and Persistence in Three Environmental Compartments Sharon C

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Emergence and Fate of Siloxanes in Waste Streams: Release Mechanisms, Partitioning and Persistence in Three Environmental Compartments Sharon C Florida International University FIU Digital Commons FIU Electronic Theses and Dissertations University Graduate School 3-23-2015 Emergence and Fate of Siloxanes in Waste Streams: Release Mechanisms, Partitioning and Persistence in Three Environmental Compartments Sharon C. Surita Florida International University, [email protected] Follow this and additional works at: http://digitalcommons.fiu.edu/etd Part of the Environmental Engineering Commons Recommended Citation Surita, Sharon C., "Emergence and Fate of Siloxanes in Waste Streams: Release Mechanisms, Partitioning and Persistence in Three Environmental Compartments" (2015). FIU Electronic Theses and Dissertations. Paper 1899. http://digitalcommons.fiu.edu/etd/1899 This work is brought to you for free and open access by the University Graduate School at FIU Digital Commons. It has been accepted for inclusion in FIU Electronic Theses and Dissertations by an authorized administrator of FIU Digital Commons. For more information, please contact [email protected]. FLORIDA INTERNATIONAL UNIVERSITY Miami, Florida EMERGENCE AND FATE OF SILOXANES IN WASTE STREAMS: RELEASE MECHANISMS, PARTITIONING AND PERSISTENCE IN THREE ENVIRONMENTAL COMPARTMENTS A dissertation submitted in partial fulfillment of the requirements for the degree of DOCTOR OF PHILOSPHY in CIVIL ENGINEERING by Sharon Czarina Surita 2015 To: Dean Amir Mirmiran College of Engineering & Computing This dissertation, written by Sharon Czarina Surita, and entitled Emergence and Fate of Siloxanes in Waste Streams: Release Mechanisms, Partitioning and Persistence in Three Environmental Compartments, having been approved in respect to style and intellectual content, is referred to you for judgment. We have read this dissertation and recommend that it be approved. _______________________________________ Omar I Abdul-Aziz _______________________________________ Shonali Laha _______________________________________ Walter Tang _______________________________________ Krishnaswamy Jayachandran ______________________________________ Berrin Tansel, Major Professor Date of Defense: March 23, 2015 The dissertation of Sharon Czarina Surita is approved. _______________________________________ Dean Amir Mirmiran College of Engineering & Computing _______________________________________ Dean Lakshmi N. Reddi University Graduate School Florida International University, 2014 ii © Copyright 2015 by Sharon Czarina Surita All rights reserved. iii DEDICATION I dedicate this dissertation to my husband, son and mother. Without their patience, understanding, support, and love the completion of this work would not have been possible. iv ACKNOWLEDGMENTS This dissertation would not have been completed without the support of numerous people. I wish to thank the members of my committee, Dr. Shonali Laha, Dr. Krishnaswamy Jayachandran, Dr. Omar Abdul-Aziz, Dr. Walter Tang and Dr. Berrin Tansel, as well as Dr. Fuentes, the Associate Chair of the Department for their support, patience, and insight. Their gentle, but firm direction has been most appreciated. Dr. Berrin Tansel, as my academic advisor, was particularly helpful in guiding me toward a comprehensive understanding of research methodologies. I would also like to thank Dr. Tansel for having confidence in my abilities to excel in my studies and propel me towards publication of several papers in high-impact journals and providing me with the opportunity to participate in significant research endeavors such as evaluating fate and transport mechanisms of siloxanes in the environment. I would like to thank the Hinkley Center for Solid and Hazardous Waste Management of University of Florida, Gainesville, Florida for providing funding for research, sampling and analytical procedures. I also would like to acknowledge and thank Florida International University for financial support provided by the FIU Graduate School Dissertation Year Fellowship and allowing me the opportunity to focus exclusively on my research. I thankfully acknowledge the contribution of many individuals involved in field sampling and analysis. Mr. Myers and staff at the South Florida Water Management District, Rodney Sasina, Collin Douglas and Jorge Fernandez provided immeasurable help in sample collection. Dr. Yusuf Emirov’s help with micro-analysis was very instrumental in my research. Technical Advisory Group (TAG) members including, v Manny Moncholi, Tarek Abichou, and Wieland Uchdorf offered intellectual guidance to continue the flow of research efforts. My coursework throughout the Curriculum and Instruction program equipped me with the tools to explore and decipher present issues and predict future trends in my subject area. Finally, I would like to thank my husband, Kenneth for his support and encouragement and my ever-cheerful son, Xavier who gives me happiness and has been a blessing in my life. vi ABSTRACT OF THE DISSERTATION EMERGENCE AND FATE OF SILOXANES IN WASTE STREAMS: RELEASE MECHANISMS, PARTITIONING AND PERSISTENCE IN THREE ENVIRONMENTAL COMPARTMENTS by Sharon Czarina Surita Florida International University, 2015 Miami, Florida Professor Berrin Tansel, Major Professor Siloxanes are widely used in personal care and industrial products due to their low surface tension, thermal stability, antimicrobial and hydrophobic properties, among other characteristics. Volatile methyl siloxanes (VMS) have been detected both in landfill gas and biogas from anaerobic digesters at wastewater treatment plants. As a result, they are released to gas phase during waste decomposition and wastewater treatment. During transformation processes of digester or landfill gas to energy, siloxanes are converted to silicon oxides, leaving abrasive deposits on engine components. These deposits cause increased maintenance costs and in some cases complete engine overhauls become necessary. The objectives of this study were to compare the VMS types and levels present in biogas generated in the anaerobic digesters and landfills and evaluate the energetics of siloxane transformations under anaerobic conditions. Siloxane emissions, resulting from disposal of silicone-based materials, are expected to increase by 29% within the next 10 years. Estimated concentrations and the risk factors of exposure to siloxanes were vii evaluated based on the initial concentrations, partitioning characteristics and persistence. It was determined that D4 has the highest risk factor associated to bioaccumulation in liquid and solid phase, whereas D5 was highest in gas phase. Additionally, as siloxanes are combusted, the particle size range causes them to be potentially hazardous to human health. When inhaled, they may affix onto the alveoli of the lungs and may lead to development of silicosis. Siloxane-based COD-loading was evaluated and determined to be an insignificant factor concerning COD limits in wastewater. Removal of siloxane compounds is recommended prior to land application of biosolids or combustion of biogas. A comparison of estimated costs was made between maintenance practices for removal of siloxane deposits and installation/operation of fixed-bed carbon absorption systems. In the majority of cases, the installation of fixed- bed adsorption systems would not be a feasible option for the sole purpose of siloxane removal. However they may be utilized to remove additional compounds simultaneously. viii TABLE OF CONTENTS CHAPTER PAGE 1. Introduction ..................................................................................................................... 1 References ...................................................................................................................... 5 2. Siloxanes in MSW: Historical and projected trends in waste fractions with increasing siloxane use .................................................................................................... 7 2.1 Introduction .......................................................................................................... 7 2.2 Methodology ................................................................................................... 13 2.2.1 Silicone trend analysis ................................................................................ 13 2.2.2 Justification of sector alignment ................................................................. 15 2.2.3 Municipal waste degradation ...................................................................... 20 2.2.4 Silicone-containing waste projections ........................................................ 21 2.3 Results ................................................................................................................ 23 2.4 Conclusions ........................................................................................................ 27 References ..................................................................................................................... 28 3. Oxidation of siloxanes during biogas combustion and nanotoxicity of Si-based particles released to the atmosphere (published in Environmental Toxicology and Pharmacology) .................................................................................................................. 31 3.1 Introduction ........................................................................................................ 31 3.2 Siloxane levels in biogas .................................................................................... 35 3.2.1 Quantities of silicon dioxide deposited and released to the atmosphere .... 35 3.2.2 Characteristics
Load more

Recommended publications
  • 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.
    [Show full text]
  • 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:
    [Show full text]
  • 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.
    [Show full text]
  • 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.
    [Show full text]
  • 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.
    [Show full text]
  • Benzoic Acid
    A Publication of Reliable Methods for the Preparation of Organic Compounds Working with Hazardous Chemicals The procedures in Organic Syntheses are intended for use only by persons with proper training in experimental organic chemistry. All hazardous materials should be handled using the standard procedures for work with chemicals described in references such as "Prudent Practices in the Laboratory" (The National Academies Press, Washington, D.C., 2011; the full text can be accessed free of charge at http://www.nap.edu/catalog.php?record_id=12654). All chemical waste should be disposed of in accordance with local regulations. For general guidelines for the management of chemical waste, see Chapter 8 of Prudent Practices. In some articles in Organic Syntheses, chemical-specific hazards are highlighted in red “Caution Notes” within a procedure. It is important to recognize that the absence of a caution note does not imply that no significant hazards are associated with the chemicals involved in that procedure. Prior to performing a reaction, a thorough risk assessment should be carried out that includes a review of the potential hazards associated with each chemical and experimental operation on the scale that is planned for the procedure. Guidelines for carrying out a risk assessment and for analyzing the hazards associated with chemicals can be found in Chapter 4 of Prudent Practices. The procedures described in Organic Syntheses are provided as published and are conducted at one's own risk. Organic Syntheses, Inc., its Editors, and its Board of Directors do not warrant or guarantee the safety of individuals using these procedures and hereby disclaim any liability for any injuries or damages claimed to have resulted from or related in any way to the procedures herein.
    [Show full text]
  • 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.
    [Show full text]
  • Comparing PPG Polysiloxane Coatings and Traditional Coating Systems
    Comparing PPG Polysiloxane Coatings and Traditional Coating Systems INTRODUCTION The last two decades have seen continuous This document examines the chemistry behind AND EXECUTIVE improvement in the performance and aesthetic PSX 700 and PSX 700SG coatings, and explains SUMMARY versatility of polysiloxane coatings. Recently, PPG why they offer superior long-term economic and achieved a significant technological advance with environmental performance compared to traditional the launch of PSX® 700SG, a new semi-gloss (SG) epoxy/urethane and epoxy/silicone-alkyd coating polysiloxane coating developed for applications systems. where the ultra-high solids content, long-term weatherability and performance of standard polysiloxane coatings are desired, but the inherent high gloss of the coating is not. PSX 700 PSX 700SG is the latest advance in the PSX 700 Since their introduction two decades ago, poly- COATINGS line of polysiloxane coatings by PPG. It offers siloxane coatings have continued to grow in both TECHNOLOGY all the performance and aesthetic advantages of development and application. Like urethanes and earlier PSX 700 coatings, but with a new propri- alkyds, they are recognized as a distinct category etary formulation that tempers the high-gloss of products within the coatings industry and, appearance of earlier-generation products. according to listings in a major industry trade magazine, the number of polysiloxane coatings “PSX 700SG is the latest The origins of the PSX 700 product line can be manufacturer tripled between 2000 and 2004. traced to 1994 when Ameron International, which advance in the PSX 700 line of was acquired by PPG in 2006, introduced the Even more importantly, polysiloxanes are now a polysiloxane coatings by PPG.” first polysiloxane coatings to the protective and preferred coating system for numerous industrial, marine coatings market.
    [Show full text]
  • Siloxane Sampling, Analysis and Data Reporting Recommendations on Standardization for the Biogas Utilization Industry
    Siloxane Sampling, Analysis and Data Reporting Recommendations on Standardization for the Biogas Utilization Industry Jeffrey L. Pierce, P.E. Senior Vice President SCS Energy 14th Annual EPA LMOP Conference and Project Expo January 18-20, 2011 Baltimore, Maryland Siloxanes – What and Why? • Siloxanes are volatile organic silicon compounds (VOSCs) • Widely used in personal health and beauty products and in commercial applications • Found in the ppmv level in landfill gas and WWTP digester gas • When burned as a fuel, the silicon (Si) in siloxane oxidizes to silica (SiO2) • Silica deposits cause performance and maintenance problems with LFGE equipment Silanes and Silanols • Silanes and silanols are also increasingly useful VOSCs • Silanes and silanols are also present in landfill gas and WWTP digester gas • Trimethylsilanol is frequently found in biogas and in large quantities • If lab is not reporting at least some silanes and silanols, you are not capturing a large portion of the VOSCs in your test program Common VOSCs in Landfill Gas Formal Name AKA Formula Hexamethylcyclotrisiloxane D3 Si3-O3-(CH3)6 Octamethylcyclotetrasiloxane D4 Si4-O4-(CH3)8 Decamethylcyclopentasiloxane D5 Si5-O5-(CH3)10 Hexamethyldisiloxane L2 Si2-O-(CH3)6 Octamethyltrisiloxane L3 Si3-O2-(CH3)8 Trimethylsilanol MOH Si-(CH3)3-OH Properties of Selected VOSCs Vapor Boiling Water % Compound MW Pressure Point Solubility Silicon mmHg (ºF) (mg/l) D3 222 .380 10 273 1.56 D4 297 .378 1.3 347 0.06 D5 371 .379 0.4 410 0.02 L3 236 .357 3.9 306 0.04 MOH 90 .312 210 Reporting
    [Show full text]
  • Silicone Rubber Compounds Meeting the Increasingly Diverse and Sophisticated Needs of Industry with the Unique Properties of Silicone Rubbers
    Characteristic properties of Silicone Rubber Compounds Meeting the increasingly diverse and sophisticated needs of industry with the unique properties of silicone rubbers The main ingredients of Shin-Etsu’s silicone rubber compounds are unique raw silicone rubber gum and high-purity silica. Silicone rubber compounds have characteristics of both inorganic and organic materials, and offer a number of advantages not found in other organic rubbers. Silicone rubbers have fine electrical properties, good chemical stability and flame retardancy, and superior resistance to heat and cold. They are thus used in nearly every industry to improve the quality and functionality of products including electric and electronic equipment, office automation equipment, automobiles, food products, household goods, and leisure products. ■ Contents General properties of silicone 3 Heat and cold resistance 4 Weatherability 5 Moisture and steam resistance 5 Resistance to oils, solvents, and other chemicals 6, 7 Electrical insulation 8 Thermal conductivity 9 Flame retardancy 9 Electrical conductivity 9 Compression set 10 Flex fatigue resistance 10 Tear strength and tensile strength 11 Gas permeability 12 Transparency and coloring properties 12 Radiation resistance 13 Vibration absorption 14 Releasability and Non-corrosivity 14 Physiologically inert 14 The fine properties of silicone rubber 15 2 General properties of silicone High binding energy The siloxane bonds (–Si–O–Si–) that form the backbone of silicone (dimethyl polysiloxane) are highly stable. At 433 kJ/mol, their binding energy is higher than that of carbon bonds (C–C), at 355 kJ/mol. Thus, compared to common organic polymers, silicone rubbers have higher heat resistance and chemical stability, and provide better electrical insulation.
    [Show full text]
  • (12) United States Patent (10) Patent No.: US 7.455,998 B2 Brandstadt Et Al
    US007455998B2 (12) United States Patent (10) Patent No.: US 7.455,998 B2 Brandstadt et al. (45) Date of Patent: Nov. 25, 2008 (54) METHODS FOR FORMING STRUCTURALLY 2004/OO7781.6 A1 4/2004 Brandstadt et al. DEFINED ORGANIC MOLECULES FOREIGN PATENT DOCUMENTS CA 2422600 * 3f2OO2 (75) Inventors: Kurt Friedrich Brandstadt, WO WO 90,09446 A 8, 1990 Frankenmuth, MI (US); Thomas WO WO 02/22842 A1 3, 2002 Howard Lane, Midland, MI (US); John WO WOO3/O542O5 A2 T 2003 C. Saam, Midland, MI (US); Joseph C. OTHER PUBLICATIONS McAuliffe, Sunnyvale, CA (US) J.N. Cha et al. “Silicatein Filaments and Subunits From a Marine Sponge Direct the Polymerization of Silica and Silcones. In vitro'. (73) Assignees: Dow Corning Corporation, Midland, PNAS 96: 361-365. (Jan. 1999).* MI (US); Genencor International, Inc., 1997 Sigma Catalog, pp. 652-653.* Palo Alto, CA (US) Bassindale et al., Enzyme-catalysed siloxane bond formation, Jour nal of Inorganic Biochemistry, May 21, 2003, pp. 401–406, Elsevier (*) Notice: Subject to any disclaimer, the term of this Inc. patent is extended or adjusted under 35 Fattaklhova et al., Fermentative Hydrolysis of the Silicon-Oxygen Bond, Access Russia, Inc. pp. 100-105. U.S.C. 154(b) by 480 days. Nishino et al., Enzymatic silicon oligomerization catalyzed by a lipid-coated lipase, The Royal Society of Chemistry 2002, pp. 2684 (21) Appl. No.: 10/791.951 2685. Bassindale et al., Biocatalysis of Siloxane Bonds, Polymer Preprints (22) Filed: Mar. 3, 2004 2003, 44(2), pp. 570-571. Bassindale et al: "Siloxane Biocatalysis. Polymer Preprints.” Mid (65) Prior Publication Data Mar.
    [Show full text]
  • Siloxane and Silane-Functionalized Polynorbornenes As Membranes for Passive Carbon Dioxide Separation
    University of Tennessee, Knoxville TRACE: Tennessee Research and Creative Exchange Masters Theses Graduate School 12-2015 Siloxane and Silane-functionalized Polynorbornenes as Membranes for Passive Carbon Dioxide Separation Eunice Koheun Hong University of Tennessee - Knoxville, [email protected] Follow this and additional works at: https://trace.tennessee.edu/utk_gradthes Part of the Environmental Chemistry Commons, Organic Chemistry Commons, and the Polymer Chemistry Commons Recommended Citation Hong, Eunice Koheun, "Siloxane and Silane-functionalized Polynorbornenes as Membranes for Passive Carbon Dioxide Separation. " Master's Thesis, University of Tennessee, 2015. https://trace.tennessee.edu/utk_gradthes/3585 This Thesis is brought to you for free and open access by the Graduate School at TRACE: Tennessee Research and Creative Exchange. It has been accepted for inclusion in Masters Theses by an authorized administrator of TRACE: Tennessee Research and Creative Exchange. For more information, please contact [email protected]. To the Graduate Council: I am submitting herewith a thesis written by Eunice Koheun Hong entitled "Siloxane and Silane- functionalized Polynorbornenes as Membranes for Passive Carbon Dioxide Separation." I have examined the final electronic copy of this thesis for form and content and recommend that it be accepted in partial fulfillment of the equirr ements for the degree of Master of Science, with a major in Chemistry. Brian K. Long, Major Professor We have read this thesis and recommend its acceptance: Alexei P. Sokolov, Ampofo K. Darko Accepted for the Council: Carolyn R. Hodges Vice Provost and Dean of the Graduate School (Original signatures are on file with official studentecor r ds.) Siloxane and Silane-functionalized Polynorbornenes as Membranes for Passive Carbon Dioxide Separation A Thesis Presented for the Master of Science Degree The University of Tennessee, Knoxville Eunice Koheun Hong December 2015 Copyright © 2015 by Eunice Koheun Hong All rights reserved.
    [Show full text]