DOCSLIB.ORG

Synthesis of Ultrahigh Molecular Weight Polymers with Low Pdis By

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Synthesis of Ultrahigh Molecular Weight Polymers with Low Pdis By molecules Article Synthesis of Ultrahigh Molecular Weight Polymers with Low PDIs by Polymerizations of 1-Decene, 1-Dodecene, and 1-Tetradecene by i Cp*TiMe2(O-2,6- Pr2C6H3)–Borate Catalyst Kotohiro Nomura * , Sarntamon Pengoubol and Wannida Apisuk Department of Chemistry, Tokyo Metropolitan University, 1-1 Minami Osawa, Hachioji, Tokyo 192-0397, Japan; [email protected] (S.P.); [email protected] (W.A.) * Correspondence: [email protected]; Tel./Fax: +81-42-6772547 Academic Editor: Giovanni Ricci Received: 29 March 2019; Accepted: 23 April 2019; Published: 25 April 2019 Abstract: Polymerizations of 1-decene (DC), 1-dodecene (DD), and 1-tetradecene (TD) by i Cp*TiMe2(O-2,6- Pr2C6H3)(1)–[Ph3C][B(C6F5)4] (borate) catalyst have been explored in the presence of Al cocatalyst. The polymerizations of DC and DD, in n-hexane containing a mixture of i Al Bu3 and Al(n-C8H17)3, proceeded with high catalytic activities in a quasi-living manner, affording high molecular weight polymers (activity 4120–5860 kg-poly(DC)/mol-Ti h, Mn for 5 · poly(DC) = 7.04–7.82 10 , after 20 min at 30 ◦C). The PDI (Mw/Mn) values in the resultant × − i polymers decreased upon increasing the ratio of Al(n-C8H17)3/Al Bu3 with decreasing the activities at 30 ◦C. The PDI values also became low when these polymerizations were conducted at low − 5 temperatures ( 40 or 50 ◦C); high molecular weight poly(DD) with low PDI (Mn = 5.26 10 , − − i × Mw/Mn = 1.16) was obtained at 50 ◦C. The TD polymerization using 1–borate–Al Bu3 catalyst − 6 (conducted in n-hexane at 30 ◦C) afforded ultrahigh molecular weight poly(TD) (Mn = 1.02 10 , − i × Mw/Mn = 1.38), and the PDI values also decreased with increasing the Al(n-C8H17)3/Al Bu3 ratio. Keywords: polymerization; titanium complex; catalyst; α-olefin; half-titanocene; borate 1. Introduction Design of molecular catalysts for olefin polymerization has been considered as an important subject in synthesis of new polymers with specified functions. The recent progress in the catalyst developments provides new possibilities [1–17]. Although crystalline isotactic polypropylene has been widely used in our daily life, use of amorphous poly(α-olefin)s (APAOs) showed less attention due to their inherent stickiness and softness. APAOs possess high melt-flow rate with low density, and are used in hot melt applications, these also improve adhesion on wood and polypropylene, and improve the free-flowing ability of their granules. It has been known recently that ultrahigh molecular weight poly(α-olefin)s can be used as drag reducing agents (DRAs) in pipeline transport methods for crude oil and petroleum products, because of their ability to reduce pumping power and increase piping system capacity [18–21]. Moreover, poly(α-olefin)s with alkyl chain length greater than six have bottlebrush architecture (branched macromolecules with a high graft density along their backbone) [22–25], and are the simplest bottlebrush polymers, with their backbone and side chains consisting of alkanes. As shown below (Table1), polymerization of α-olefin (1-hexene, 1-octene, 1-decene, etc.) by ordinary metallocene catalysts gave oligomers [26–28]. Several examples [28–33] were known for t synthesis of (ultra)high molecular weight poly(1-hexene)s by using [2,2-(O-4-Me-6- Bu-C6H3)2S]TiCl2 (in the presence of specified modified MMAO) [31,32], or (C5HMe4)2HfCl2 (under ultrahigh Molecules 2019, 24, 1634; doi:10.3390/molecules24081634 www.mdpi.com/journal/molecules Molecules 2019, 24, x 2 of 11 (in the presence of specified modified MMAO) [31,32], or (C5HMe4)2HfCl2 (under ultrahigh pressure) [29]. One example was known for synthesis of isotactic poly(1-hexene)s with ultrahigh molecular Molecules 2019, 24, 1634 2 of 10 weights by titanium complexes containing diamine bis(phenolate) ligands [30]. Several examples were also known for synthesis of poly(α-olefin)s with rather high molecular weights [27,34–42]. pressure)However, [29 synthesis]. One example of ultrahigh was knownmolecular for weight synthesis polymers of isotactic by polymerization poly(1-hexene)s of withhigher ultrahigh α-olefins molecular(1-decene, weights 1-dodecene, by titanium 1-tetradecene complexes, etc.) containing still have diamine been bis(phenolate)limited [28], probably ligands [ 30due]. Several to their examplestendency were to undergo also known β-hydrogen for synthesis elimination of poly(α -olefin)sbefore subsequent with rather/rep higheated molecular insertion weights. [27,34–42]. However,We synthesisrecently reported of ultrahigh synthesis molecular of high weight molecular polymers weight by poly polymerization(α-olefin)s by of p higherolymeriαz-olefinsations of (1-decene,1-decene, 1-dodecene, 1-dodecene 1-tetradecene,, 1-hexadecene, etc.) and still 1- haveoctadecene been limited by Cp*TiCl [28], probably2(O-2,6-iPr due2C6 toH3 their)–MAO tendency catalyst to[28] undergo, andβ -hydrogenthe Mn values elimination in the before resultant subsequent polymers/repeated were insertion. higher than those prepared by [MeWe2Si(C recently5Me4)(N reportedtBu)]TiCl synthesis2 and Cp of2ZrCl high2 molecular(Table 1)weight [28]. poly(Moreover,α-olefin)s Cp*TiMe by polymerizations2(O-2,6-iPr2C6H3) i of(1 1-decene,)–[Ph3C][B(C 1-dodecene,6F5)4] (borate) 1-hexadecene, catalyst showed and 1-octadecenethe higher catalytic by Cp*TiCl activities2(O-2,6-, affordingPr2C6H3 )–MAOultrahigh catalystmolecular [28], weight and the poly(1Mn -valuesoctene)s in and the poly(1 resultant-dodecene)s polymers (Table were 1) higher [28]. On than the those other preparedhand, we byalso t i [Mereported2Si(C5Me that4)(N 1-Bu)]TiClhexene polymerization2 and Cp2ZrCl 2by(Table 1–borate1)[ 28catalyst]. Moreover, proceeded Cp*TiMe in a quasi2(O-2,6--livingPr2 Cmanner6H3) 6 (1)–[Phunder3 C][B(Ccertain6 Fconditions5)4] (borate) to afford catalyst ultrahigh showed molecular the higher weight catalytic poly(1 activities,-hexene)s aff (ordingMn ≥ 1.0 ultrahigh–1.9 × 10 ) molecular[33]. Therefore, weight we poly(1-octene)s herein present and synthesis poly(1-dodecene)s of high molecular (Table 1weight)[ 28]. polymers On the other by polymerizations hand, we also reportedof 1-decene that 1-hexene (DC), 1- polymerizationdodecene (DD) by, and1–borate 1-tetradecene catalyst proceeded(TD) with inlow a quasi-living PDI (Mw/M mannern) values under using 6 certain1-borate conditions catalyst toin the afford presence ultrahigh of Al molecular cocatalyst weight (Scheme poly(1-hexene)s 1). (Mn 1.0–1.9 10 )[33]. ≥ × Therefore, we herein present synthesis of high molecular weight polymers by polymerizations of i 1-deceneTable (DC), 1. 1-dodecenePolymerization (DD), of 1 and-octene 1-tetradecene (OC) and 1- (TD)dodecene with (DD), low PDIusing (M Cp*TiXw/Mn)2(O values-2,6- Pr using2C6H31) -borate[X = catalystCl, in Me the (1 presence)], [Me2Si(C of5Me Al4 cocatalyst)(NtBu)]TiCl (Scheme2, Cp2ZrCl1).2—cocatalyst systems [28]. a b c n d w n d catalyst α-olefin cocatalyst time/min TON Activity i M M /M Table 1. Polymerizationi of 1-octene (OC) and 1-dodecene (DD), using Cp*TiX2(O-2,6- Pr2C6H3) [X = Cl, Cp*TiCl2(O-2,6- Pr2C6H3) t OC MAO 30 9950 a 2240 501000 1.42 Me (1)], [Me2Si(Ci 5Me4)(N Bu)]TiCl2, Cp2ZrCl2—cocatalyst systems [28]. Cp*TiCl2(O-2,6- Pr2C6H3) DD MAO 30 4120 1390 525000 1.35 i b c d d Cp*TiMeCatalyst2(O-2,6- Pr2C6H3α)-Olefin OC Cocatalystborate Time/min20 TON7080 Activity2380 Mn1970000M w/Mn 2.04 i i Cp*TiMeCp*TiCl2(O-2,6-2(O-Pr2,62C-6PrH32)C6H3) OCDD MAOborate 3020 99503730 22401880 5010001320000 1.42 1.99 Cp*TiCl (O-2,6-iPr Ct H ) DD MAO 30 4120 1390 525000 1.35 [Me2Si(C2 5Me4)(N2 Bu)]TiCl6 3 2 OC MAO 30 4810 1080 292000 1.64 i OC borate 20 7080 2380 1970000 2.04 Cp*TiMe2(O-2,6- Pr2Ct 6H3) [Me2Si(C5Me4i)(N Bu)]TiCl2 Cp*TiMe2(O-2,6- Pr2C6H3) DDDD borateMAO 2030 37302060 1880690 1320000351000 1.99 1.33 t [Me2Si(C5MeCp4)(N2ZrClBu)]TiCl2 2 OCOC MAOMAO 3030 481021300 10804790 2920004100 1.64 1.55 t [Me2Si(C5Me4)(N Bu)]TiCl2 DD MAO 30 2060 690 351000 1.33 Cp2ZrCl2 DD MAO 30 15400 5190 5000 1.57 Cp2ZrCl2 OC MAO 30 21300 4790 4100 1.55 a ConditionsCp2ZrCl2 (MAO cocatalyst):DD Complex MAO 1.0 μmol, 30 α-olefin 15400 5.0 mL, d- 5190MAO (prepared 5000 by removing 1.57 a Conditionstoluene and (MAO AlMe cocatalyst):3 from ordinary Complex MAO) 1.0 µmol, 2.0α mmol,-olefin 5.025 mL,°C; C d-MAOonditions (prepared (borate by cocata removinglyst): toluene Complex and 1 AlMe3 from ordinary MAO) 2.0 mmol, 25 ◦C; Conditionsi (borate cocatalyst): Complex 1 0.25 µmol, olefin 5.0b mL, 0.25 µmol,i olefin 5.0 mL, −30 °C, Al Bu3/[Ph3C][B(Cb6F5)4]/Ti = 500/3.0/1.0 (molar ratio). TON 30 ◦C, Al Bu3/[Ph3C][B(C6F5)4]/Ti = 500/3.0/1.0 (molar ratio). TON (turnover number) = (mmol of α-olefin reacted)− (turnover/(mmol-Ti). number)c Activity = (mmol= kg-polymer of α-olefin/mol-Ti reacted)/(mmolh. d Gel-permeation-Ti). c chromatographyActivity = kg- (GPC)polymer/mol data THF-Ti·h vs.. d · polystyreneGel-permeation standards. chromatography (GPC) data THF vs. polystyrene standards. Scheme 1. Polymerization of 1-decene (DC), 1-dodecene (DD), and 1-tetradecene (TD) using Scheme 1. Polymerizationi of 1-decene (DC), 1-dodecene (DD), and 1-tetradecene (TD) using Cp*TiMe2(O-2,6- Pr2C6H3)(1)–[Ph3C][B(C6F5)4] catalyst in the presence of Al cocatalyst. Cp*TiMe2(O-2,6-iPr2C6H3) (1)–[Ph3C][B(C6F5)4] catalyst in the presence of Al cocatalyst.
Load more

Recommended publications
  • Alfa Olefins Cas N
    OECD SIDS ALFA OLEFINS FOREWORD INTRODUCTION ALFA OLEFINS CAS N°:592-41-6, 111-66-0, 872-05-9, 112-41-4, 1120-36-1 UNEP PUBLICATIONS 1 OECD SIDS ALFA OLEFINS SIDS Initial Assessment Report For 11th SIAM (Orlando, Florida, United States 1/01) Chemical Name: 1-hexene Chemical Name: 1-octene CAS No.: 592-41-6 CAS No.: 111-66-0 Chemical Name: 1-decene Chemical Name: 1-dodecene CAS No.: 872-05-9 CAS No.: 112-41-4 Chemical Name: 1-tetradecene CAS No.: 1120-36-1 Sponsor Country: United States National SIDS Contract Point in Sponsor Country: United States: Dr. Oscar Hernandez Environmental Protection Agency OPPT/RAD (7403) 401 M Street, S.W. Washington, DC 20460 Sponsor Country: Finland (for 1-decene) National SIDS Contact Point in Sponsor Country: Ms. Jaana Heiskanen Finnish Environment Agency Chemicals Division P.O. Box 140 00251 Helsinki HISTORY: SIDS Dossier and Testing Plan were reviewed at the SIDS Review Meeting or in SIDS Review Process on October 1993. The following SIDS Testing Plan was agreed: No testing ( ) Testing (x) Combined reproductive/developmental on 1-hexene, combined repeat dose/reproductive/developmental on 1-tetradecene and acute fish, daphnid and algae on 1- tetradecene. COMMENTS: The following comments were made at SIAM 6 and have been incorporated in this version of the SIAR: 2 UNEP PUBLICATIONS OECD SIDS ALFA OLEFINS 1. The use of QSAR calculations for aquatic toxicity, 2. More quantitative assessment of effects; and 3. Provide more details for each endpoint. The following comments were made at SIAM 6, but were not incorporated into the SIAR for the reasons provided: 1.
    [Show full text]
  • Radical Approaches to Alangium and Mitragyna Alkaloids
    Radical Approaches to Alangium and Mitragyna Alkaloids A Thesis Submitted for a PhD University of York Department of Chemistry 2010 Matthew James Palframan Abstract The work presented in this thesis has focused on the development of novel and concise syntheses of Alangium and Mitragyna alkaloids, and especial approaches towards (±)-protoemetinol (a), which is a key precursor of a range of Alangium alkaloids such as psychotrine (b) and deoxytubulosine (c). The approaches include the use of a key radical cyclisation to form the tri-cyclic core. O O O N N N O O O H H H H H H O N NH N Protoemetinol OH HO a Psychotrine Deoxytubulosine b c Chapter 1 gives a general overview of radical chemistry and it focuses on the application of radical intermolecular and intramolecular reactions in synthesis. Consideration is given to the mediator of radical reactions from the classic organotin reagents, to more recently developed alternative hydrides. An overview of previous synthetic approaches to a range of Alangium and Mitragyna alkaloids is then explored. Chapter 2 follows on from previous work within our group, involving the use of phosphorus hydride radical addition reactions, to alkenes or dienes, followed by a subsequent Horner-Wadsworth-Emmons reaction. It was expected that the tri-cyclic core of the Alangium alkaloids could be prepared by cyclisation of a 1,7-diene, using a phosphorus hydride to afford the phosphonate or phosphonothioate, however this approach was unsuccessful and it highlighted some limitations of the methodology. Chapter 3 explores the radical and ionic chemistry of a range of silanes.
    [Show full text]
  • Self-Metathesis of 1-Octene Using Alumina-Supported Re2o7 in Supercritical CO2
    Top Catal DOI 10.1007/s11244-008-9154-4 ORIGINAL PAPER Self-Metathesis of 1-Octene Using Alumina-Supported Re2O7 in Supercritical CO2 Massimo Fabris Æ Cindy Aquino Æ Antony J. Ward Æ Alvise Perosa Æ Thomas Maschmeyer Æ Maurizio Selva Ó Springer Science+Business Media, LLC 2009 Abstract In this contribution we describe the use of basic science has been applied for the benefit of man, heterogeneous catalysts for the liquid-phase self-metathesis society and the environment’’.1 Their contribution was of 1-octene in supercritical CO2. Our work aims at recognized for understanding the mechanism, and for addressing the mass-transfer problems associated with such developing very efficient and selective discrete metal- reaction systems. By coupling a heterogeneous supported based catalysts. Re2O7 catalyst with the use of scCO2, the self-metathesis Nonetheless, one should not forget that the metathesis of 1-octene takes place by and large much more rapidly reaction using heterogeneous catalysis has been an estab- than in traditional solvent media, and furthermore, by using lished industrial process since 1966, based on the use of scCO2 the overall efficiency and sustainability of the supported (usually on silica and alumina) metal oxides transformation can be improved. such as tungsten, nickel, cobalt, rhenium, and molybde- num. Three significant examples come to mind and are Keywords Metathesis Á 1-Octene Á Supercritical CO2 Á here recalled briefly. [1]. Re/Al O 2 3 1. The historic Phillips triolefin process for the produc- tion of ethene and 2-butene from propene using a WO /SiO catalyst, [2] that was shut down in 1972 1 Introduction 3 2 after 6 years of operation due to increased demand for propene, and later reutilized in the reverse direction to The metathesis of olefins is a very elegant and widely produce propene.
    [Show full text]
  • Selective Oxidation of Polynuclear Aromatic Hydrocarbons
    SELECTIVE OXIDATION OF POLYNUCLEAR AROMATIC HYDROCARBONS Thesis submitted in accordance with the requirements of Cardiff University for the degree of Doctor of Philosophy EWA NOWICKA July 2012 DECLARATION This work has not been submitted in substance for any other degree or award at this or any other university or place of learning, nor is being submitted concurrently in candidature for any degree or other award. Signed ………………………………………… (candidate) Date ................................. STATEMENT 1 This thesis is being submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy Signed ………………………………………… (candidate) Date ………………………… STATEMENT 2 This thesis is the result of my own independent work/investigation, except where otherwise stated. Other sources are acknowledged by explicit references.The views expressed are my own. Signed ………………………………………… (candidate) Date ………………………… STATEMENT 3 I hereby give consent for my thesis, if accepted, to be available for photocopying and for inter-library loan, and for the title and summary to be made available to outside organisations. Signed ………………………………………… (candidate) Date ………………………… STATEMENT 4: PREVIOUSLY APPROVED BAR ON ACCESS I hereby give consent for my thesis, if accepted, to be available for photocopying and for inter-library loans after expiry of a bar on access previously approved by the Academic Standards & Quality Committee. Signed ………………………………………… (candidate) Date ………………………… “You never fail until you stop trying.” Albert Einstein Abstract This thesis targets the selective oxidation of polynuclear aromatic compounds, which is considered as a preliminary step of upgrading of heavy oils, resids and bitumens to higher value materials in the liquid phase using different catalytic systems. Oxidation studies concentrated on simple model polyaromatic compounds and their alkylated derivatives.
    [Show full text]
  • Radical Hydroacylation of C-C and N-N Double Bonds in Air
    University College London Radical Hydroacylation of C-C and N-N Double Bonds in Air by Jenna Marie Ahern Submitted in partial fulfilment of the requirements for the degree of Doctor of Philosophy Declaration I, Jenna Marie Ahern, confirm that the work presented in this thesis is my own. Where information has been derived from other sources, I confirm that this has been indicated in the thesis. Jenna Marie Ahern October 2010 Radical Hydroacylation of C-C and N-N Double Bonds in Air Jenna Marie Ahern Abstract The formation of C-C and C-N bonds in modern organic synthesis is a key target for methodological advancement. Current methods of C-C and C-N bond formation often involve the use of expensive catalysts, or sub-stoichiometric reagents, which can lead to the generation of undesirable waste products. This thesis describes a novel and environmentally benign set of reaction conditions for the formation of C-C and C-N bonds by hydroacylation and this is promoted by mixing two reagents, an aldehyde and an electron-deficient double bond, under freely available atmospheric oxygen at room temperature Chapter 1 will provide an introduction to the thesis and mainly discusses methods for C-C bond formation, in particular, radical chemistry and hydroacylation. Chapter 2 describes the hydroacylation of vinyl sulfonates and vinyl sulfones (C-C double bonds) with aliphatic and aromatic aldehydes with a discussion and evidence for the mechanism of the transformation. Chapter 3 details the synthesis of precursors for intramolecular cyclisations and studies into aerobic intramolecular cyclisations. Chapter 4 describes the hydroacylation of vinyl phosphonates (C-C double bonds) and diazocarboxylates (N-N double bonds) with aliphatic and aromatic aldehydes bearing functional groups.
    [Show full text]
  • Linear Alpha-Olefins (681.5030)
    IHS Chemical Chemical Economics Handbook Linear alpha-Olefins (681.5030) by Elvira O. Camara Greiner with Yoshio Inoguchi Sample Report from 2010 November 2010 ihs.com/chemical November 2010 LINEAR ALPHA-OLEFINS Olefins 681.5030 B Page 2 The information provided in this publication has been obtained from a variety of sources which SRI Consulting believes to be reliable. SRI Consulting makes no warranties as to the accuracy completeness or correctness of the information in this publication. Consequently SRI Consulting will not be liable for any technical inaccuracies typographical errors or omissions contained in this publication. This publication is provided without warranties of any kind either express or implied including but not limited to implied warranties of merchantability fitness for a particular purpose or non-infringement. IN NO EVENT WILL SRI CONSULTING BE LIABLE FOR ANY INCIDENTAL CONSEQUENTIAL OR INDIRECT DAMAGES (INCLUDING BUT NOT LIMITED TO DAMAGES FOR LOSS OF PROFITS BUSINESS INTERRUPTION OR THE LIKE) ARISING OUT OF THE USE OF THIS PUBLICATION EVEN IF IT WAS NOTIFIED ABOUT THE POSSIBILITY OF SUCH DAMAGES. BECAUSE SOME STATES DO NOT ALLOW THE EXCLUSION OR LIMITATION OF LIABILITY FOR CONSEQUENTIAL OR INCIDENTAL DAMAGES THE ABOVE LIMITATION MAY NOT APPLY TO YOU. IN SUCH STATES SRI CONSULTING’S LIABILITY IS LIMITED TO THE MAXIMUM EXTENT PERMITTED BY SUCH LAW. Certain statements in this publication are projections or other forward-looking statements. Any such statements contained herein are based upon SRI Consulting’s current knowledge and assumptions about future events including without limitation anticipated levels of global demand and supply expected costs trade patterns and general economic political and marketing conditions.
    [Show full text]
  • Speciated Organic Gas Emissions Aircraft Turbofan Turbonjet Turboprop
    RECOMMENDED BEST PRACTICE FOR QUANTIFYING SPECIATED ORGANIC GAS EMISSIONS FROM AIRCRAFT EQUIPPED WITH TURBOFAN, TURBOJET, AND TURBOPROP ENGINES Federal Aviation Administration Office of Environment and Energy and U.S. Environmental Protection Agency Office of Transportation and Air Quality Version 1.0 May 27, 2009 ACKNOWLEDGEMENTS The Federal Aviation Administration (FAA) Office of Environment and Energy (AEE) and the U.S. Environmental Protection Agency (EPA) Office of Transportation Air Quality (OTAQ) would like to acknowledge the following agencies and individuals for their contribution to this document: FAA – Ralph Iovinelli, Mohan Gupta, Carl Ma, and Ed McQueen EPA – Bryan Manning, Rich Cook, Kent Helmer, Ken Petche, John Kinsey, Rich Wilcox, Kathryn Sergeant, Marion Hoyer, Laurel Driver, and Suzanne King California Air Resources Board – Steve Francis, Paul Allen, Wenli Yang, and Steve Church Aerodyne Research, Inc. – Rick Miake-Lye and Scott Herndon Montana State University – Berk Knighton KB Environmental Sciences, Inc. – Carrol Bryant, Mike Ratte, Paul Sanford, and Mike Kenney This document was prepared for the Federal Aviation Administration, Office of Environment and Energy by KB Environmental Sciences Inc. with assistance from CSSI Inc. in support of CSSI’s Contract DTFAWA-05-C-00044, Technical Directive Memorandum B-002-011. EXECUTIVE SUMMARY This document presents an approach to, and technical support for, the quantification of organic gas (OG) emissions including hazardous air pollutants (HAPs) from aircraft equipped with turbofan, turbojet and turboprop engines.1,2,3 This Recommended Best Practice (RBP) was produced through an inter-agency partnership and collaborative effort between the Federal Aviation Administration (FAA) Office of Environment and Energy (AEE) and the U.
    [Show full text]
  • Hydrocarbons Thermal Cracking Selectivity Depending on Their Structure and Cracking Parameters
    Master in Chemical Engineering Hydrocarbons Thermal Cracking Selectivity Depending on Their Structure and Cracking Parameters Thesis of the Master’s Degree Development Project in Foreign Environment Cláudia Sofia Martins Angeira Erasmus coordinator: Eng. Miguel Madeira Examiner in FEUP: Eng. Fernando Martins Supervisor in ICT: Doc. Ing Petr Zámostný July 2008 Acknowledgements I would like to thank Doc. Ing. Petr Zámostný for the opportunity to hold a master's thesis in this project, the orientation, the support given during the laboratory work and suggestions for improvement through the work. i Hydrocarbons Thermal Cracking Selectivity Depending on Their Structure and Cracking Parameters Abstract This research deals with the study of hydrocarbon thermal cracking with the aim of producing ethylene, one of the most important raw materials in Chemical Industry. The main objective was the study of cracking reactions of hydrocarbons by means of measuring the selectivity of hydrocarbons primary cracking and evaluating the relationship between the structure and the behavior. This project constitutes one part of a bigger project involving the study of more than 30 hydrocarbons with broad structure variability. The work made in this particular project was focused on the study of the double bond position effect in linear unsaturated hydrocarbons. Laboratory experiments were carried out in the Laboratory of Gas and Pyrolysis Chromatography at the Department of Organic Technology, Institute of Chemical Technology, Prague, using for all experiments the same apparatus, Pyrolysis Gas Chromatograph, to increase the reliability and feasibility of results obtained. Linear octenes with different double bond position in hydrocarbon chain were used as model compounds. In order to achieve these goals, the primary cracking reactions were studied by the method of primary selectivities.
    [Show full text]
  • Light Linear Alpha Olefin Market Study
    IHS CHEMICAL Light Linear Alpha Olefin Market Study Special Report Prospectus IHS CHEMICAL Contents Contents ..................................................................................................................................... 2 Introduction ................................................................................................................................ 3 Study Scope ............................................................................................................................... 5 Key Questions Addressed in the Study ...................................................................................... 7 Deliverables ............................................................................................................................... 8 Proposed Table of Contents ...................................................................................................... 9 Methodology ............................................................................................................................ 11 Study Team .............................................................................................................................. 15 Qualifications............................................................................................................................ 18 About IHS Chemical ................................................................................................................. 21 About IHS ................................................................................................................................
    [Show full text]
  • Fastest Formation Routes of Nanocarbons in Solution Plasma
    www.nature.com/scientificreports OPEN Fastest Formation Routes of Nanocarbons in Solution Plasma Processes Received: 18 August 2016 Tetsunori Morishita1, Tomonaga Ueno1,2,3, Gasidit Panomsuwan2, Junko Hieda1, Accepted: 24 October 2016 Akihito Yoshida1, Maria Antoaneta Bratescu1 & Nagahiro Saito1,2,3 Published: 14 November 2016 Although solution-plasma processing enables room-temperature synthesis of nanocarbons, the underlying mechanisms are not well understood. We investigated the routes of solution-plasma- induced nanocarbon formation from hexane, hexadecane, cyclohexane, and benzene. The synthesis rate from benzene was the highest. However, the nanocarbons from linear molecules were more crystalline than those from ring molecules. Linear molecules decomposed into shorter olefins, whereas ring molecules were reconstructed in the plasma. In the saturated ring molecules, C–H dissociation proceeded, followed by conversion into unsaturated ring molecules. However, unsaturated ring molecules were directly polymerized through cation radicals, such as benzene radical cation, and were converted into two- and three-ring molecules at the plasma–solution interface. The nanocarbons from linear molecules were synthesized in plasma from small molecules such as C2 under heat; the obtained products were the same as those obtained via pyrolysis synthesis. Conversely, the nanocarbons obtained from ring molecules were directly synthesized through an intermediate, such as benzene radical cation, at the interface between plasma and solution, resulting in the same products as those obtained via polymerization. These two different reaction fields provide a reasonable explanation for the fastest synthesis rate observed in the case of benzene. Liquid-phase plasma1–5 has attracted the attention of several researchers engaged in plasma science, especially for applications involving materials and water treatment6–10.
    [Show full text]
  • Factors Influencing the Competitive Rates of Free-Radical Addition of Ethyl 2-Bromo
    AN ABSTRACT OF THE THESIS OF Vahid Ghodoussi for the degree of Master of Science in Chemistry presented on May 14, 1986 Title: Factors Influencing the Competitive Rates of Free-Radical Addition of Ethyl 2-Bromo- carboxylates to Selected Alkene Pairs Redacted for Privacy Abstract approved: v Gerald Jay Gleicher A study of the effects of structural modification at the alpha position of ethyl 2-bromocarboxylates on their rates of addition to two alkene pairs was undertaken. In the competition between 3-propoxypropene and 1-octene at 70°, a 37% increase in selectivity was observed in going from carboxylates generating primary radicals to those generating tertiary radicals. These results yield good correlations with electronic and/or steric parameters. When the competition between 1-methylcyclohexene and 1-octene was examined, no simple systematic variation of selectivity with structure was observed. An explanation is offered, which is based on the greater persistence of hindered carboethoxyalkyl radicals and the resultant changes in transition state structure. Factors Influencing the Competitive Rates of Free-Radical Addition of Ethyl 2-Bromocarboxylates to Selected Alkene Pairs by Vahid Ghodoussi A THESIS submitted to Oregon State University in partial fulfillment of the requirements for the degree of Master of Science Completed May 14, 1986 Commencement June 1987 APPROVED: Redacted for Privacy Professor of Chemistry in charge of major Redacted for Privacy Head of Department of Chemistry Redacted for Privacy Dean of Grrlate Sehootf Date thesis is presented May 14, 1986 Typed by Violet Jonas for Vahid Ghodoussi ACKNOWLEDGMENT First and foremost, I wish to express deep gratitude to my parents, my brother, and other members of my family for their continuous understanding and support.
    [Show full text]
  • Chm 416 Course Title: Organic Synthesis
    NATIONAL OPEN UNIVERSITY OF NIGERIA SCHOOL OF SCIENCE AND TECHNOLOGY COURSE CODE: CHM 416 COURSE TITLE: ORGANIC SYNTHESIS Course Developer/Writer: Adeniran, Oluremi Isola Department of Chemistry Faculty of Science University of Abuja, Abuja, Nigeria. MODULE 1 Oxidation Reactions Unit 1 Oxidation reactions Unit 2 Transformation of alkenes Unit 3 Transformation of alcohols Unit 4 Transformation of arenes UNIT 1 Oxidation reactions Contents 1.0 Introduction 2.0 Objectives 3.0 Main Content 3.1 Definitions 3.2 Oxidizing Reagents 4.0 Conclusion 5.0 Summary 6.0 Tutor-Marked Assignment 7.0 References/Further Reading 1.0 Introduction Oxidation as defined in ionic and free radical reactions, is a process by which an element undergoes a net loss of electrons. The concept as applied to organic covalent compounds, where elements share electrons rather than losing or gaining them is the same, but it’s often simplified and narrowed down to make it easier to recognize this process. Therefore it must be kept in mind that, while the following definition in this unit is grossly simplified, it serves the goal of quickly identifying oxidation process in many organic reactions. 2.0 Objectives At the end of this unit, students should be able to: i. Define oxidation reaction ii. Recognize oxidation in organic reactions iii. List some oxidizing reagents 3.0 Main content 3.1 Definitions Oxidation in inorganic chemistry is considered as a loss of electrons. For inorganic ions, as when Fe2+ is oxidized to Fe3+, this concept works well. Since most organic compounds are uncharged, electron gain or loss is not apparent.
    [Show full text]