Serap Soytas | Sabanci University (original) (raw)

Papers by Serap Soytas

Research paper thumbnail of Living carbocationic polymerization of isobutylene by epoxide /Lewis acid systems: The mechanism of initiation

PhDT, 2009

Living polymerization of isobutylene (IB) and subsequent controlled synthesis of ABA block copoly... more Living polymerization of isobutylene (IB) and subsequent controlled synthesis of ABA block copolymers, such as poly (styrene-b-isobutylene-b-styrene)(PSt-PIB-PSt) and poly (p-methylstyrene-b-isobutylene-bp-methylstyrene)(PpMeSt-PIB-PpMeSt), have been carried ...

Research paper thumbnail of <i>Real-time</i>FTIR monitoring of the mechanism of initiation of isobutylene polymerizations by epoxide/Lewis acid systems

Journal of Polymer Science Part A, Jun 1, 2008

ABSTRACT Real-time Fourier Transformation Infrared (FTIR) spectroscopy with a fiber optic transmi... more ABSTRACT Real-time Fourier Transformation Infrared (FTIR) spectroscopy with a fiber optic transmission probe (TR) was used to monitor the polymerization of isobutylene (IB) initiated by α-methylstyrene epoxide (MSE) and 1,2-epoxi-2,4,4-trimethylpentane (TMPO-1) in conjunction with TiCl4 and BCl3. In the presence of an equimolar amount of BCl3, MSE and TMPO-1 underwent ring opening via SN1 mechanism. In contrast to TiCl4-coinitiated reactions, no oligoether formation via SN2 mechanism was observed. TMPO-1 with excess BCl3 initiated IB polymerization, yielding a telechelic PIB carrying α-primary OH and ω-tertiary Cl functionalities with 70% initiator efficiency. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 3611–3618, 2008

Research paper thumbnail of Photothermal Electrospun Nanofibers Containing Polydopamine-Coated Halloysite Nanotubes as Antibacterial Air Filters

ACS Applied Nano Materials

Research paper thumbnail of Silicon nanocrystals-embedded carbon nanofibers from hybrid polyacrylonitrile – TEOS precursor as high-performance lithium-ion battery anodes

Journal of Alloys and Compounds, 2022

Research paper thumbnail of Specific Interactions and Self-Organization in Polymer/Functionalized Nanoparticle Systems

In this chapter, specific interactions and self-organization in nanocomposites containing functio... more In this chapter, specific interactions and self-organization in nanocomposites containing functionalized nanoparticles (NPs) are discussed. Common techniques applied for the synthesis, modification, and functionalization of inorganic NPs are summarized. The use of such NPs in the preparation of polymer-based nanocomposites and their effects on the structure–property relationships of the resulting materials are described by some representative studies reported in the literature. In particular, nanocomposites containing (1) modified silica NPs, (2) organically modified layered silicates, and (3) polyhedral oligomeric silsesquioxane (POSS) hybrids are addressed. Moreover, a general overview on the self-organization phenomenon is provided based on recent developments in the field of block copolymer-based nanocomposites.

Research paper thumbnail of Synthesis of POSS-Functionalized Polyisobutylene via Direct Initiation

Macromolecular Rapid Communications, 2009

Research paper thumbnail of Silicon-decorated carbon nanofibers as high-capacity and long-cycle life lithium-ion battery (LIB) anodes

Research paper thumbnail of Polymer Nanocomposites With Decorated Metal Oxides

Polymer Composites with Functionalized Nanoparticles, 2019

This chapter represents an overview of polymer nanocomposites containing functional metal oxide n... more This chapter represents an overview of polymer nanocomposites containing functional metal oxide nanoparticles as inorganic fillers. Metal oxide/polymer nanocomposites have received considerable attention as they are used in a wide range of applications in various fields including optoelectronic devices, biomedical applications, electromagnetic devices, optics, food packaging, photocatalysis, and many others. The desired properties of the nanocomposites could only be achieved with the good dispersion of nanostructures in the polymer matrix, which is difficult to achieve due to their specific surface area and volume effect. The surface engineered metal oxide nanoparticles overcome the aggregation problem providing improved interfacial interaction between the nanoparticles and the polymer matrix. Synthesis, surface functionalization, and nanocomposites of the metal oxide nanostructures as well as the properties and potential applications of the nanocomposites will be discussed this cha...

Research paper thumbnail of Living carbocationic polymerization of isobutylene by epoxide /Lewis acid systems: The mechanism of initiation

The objective of the work presented in this dissertation was to generate a fundamental understand... more The objective of the work presented in this dissertation was to generate a fundamental understanding of the synthesis of star-branched polyisobutylenes (PIBs) arising from hexaepoxysqualene (HES)/Lewis acid (LA) initiating systems, using BCl3 and TiCl4 as LAs. The understanding of initiation and propagation mechanisms by HES is crucial to control the number of arms and arm lengths of star PIBs expected from this initiator. The initiation by monofunctional epoxides, such as alpha-methylstyrene epoxide (MSE), 1,2-epoxy-2,4,4-trimethylpentane (TMPO-1), and 2,3-epoxy-2,4,4-trimethylpentane (TMPO-2), was investigated. In situ FTIR spectroscopy, which was highly utilized in this research, provided valuable information. Most importantly, the ability to identify the head group by in situ FTIR of growing PIB chains initiated by an epoxide, i.e. the --C--O--LA complex, contributed significantly to the understanding of initiation of IB polymerization. This technique allowed the monitoring of the rate of initiation with the multifunctional epoxy initiator. Previous research showed that TiCl4 gave 40% initiating efficiency in conjunction with the aromatic epoxy initiator MSE, whereas the aliphatic initiators TMPO-1 and TMPO-2 gave only 3 and 10% efficiency, respectively. In this research it was found that BCl3 is more efficient with the aliphatic initiator, TMPO-1, yielding an asymmetric telechelic PIB carrying an alpha-primary OH and an o-tertiary Cl functional group with 70% initiator efficiency, while MSE gave only 1--4% efficiency. The TMPO-2/BCl3 system gave 20% initiator efficiency. The various initiation mechanisms were discussed. IB polymerization was successfully initiated by HES in the presence of excess BCl3 and monitored by in situ FTIR spectroscopy. The gradual increase of the IR band assigned to the --C--O--BCl 2 group demonstrated that slow initiation was occurring. Chain extension with the HES/BCl3 initiated PIB was achieved leading to high molecular weight PIBs in the presence of TiCl4. It was also demonstrated for the first time that BCl3 invariably leads to beta-proton expulsion, leading to chain transfer in IB polymerization. In addition, 1,2-epoxycyclohexane and epoxycyclohexyl-functional siloxanes, i.e. epoxycyclohexylisobutyl polyhedral oligomeric silsesquioxane (POSS) and bis[3,4-(epoxycyclohexyl)ethyl]tetramethyldisiloxane, were found to be initiators for the polymerization of IB. 1,2-epoxycyclohexane/TiCl 4 was an efficient initiating system for the IB polymerization yielding up to 45% initiator efficiency. It was proposed that initiation of IB polymerization involves an SN2 reaction between IB and TiCl4-coordinated epoxide.

Research paper thumbnail of Mechanisms of Si Nanoparticle Formation by Molten Salt Magnesiothermic Reduction of Silica for Lithium‐ion Battery Anodes

Research paper thumbnail of One-pot synthesis of tin chalcogenide-reduced graphene oxide-carbon nanotube nanocomposite as anode material for lithium-ion batteries

Dalton Transactions

In this study, a ternary tin chalcogenide (TC)–reduced graphene oxide (RGO)–carbon nanotube (CNT)... more In this study, a ternary tin chalcogenide (TC)–reduced graphene oxide (RGO)–carbon nanotube (CNT) nanocomposite was synthesized as a lithium-ion battery (LIB) anode by a simple one-step protocol.

Research paper thumbnail of Correction: Capacitive behaviour of nanocrystalline octacalcium phosphate (OCP) (Ca8H2(PO4)6·5H2O) as an electrode material for supercapacitors: biosupercaps

Nanoscale

Correction for ‘Capacitive behaviour of nanocrystalline octacalcium phosphate (OCP) (Ca8H2(PO4)6·... more Correction for ‘Capacitive behaviour of nanocrystalline octacalcium phosphate (OCP) (Ca8H2(PO4)6·5H2O) as an electrode material for supercapacitors: biosupercaps’ by Mustafa Tuncer et al., Nanoscale, 2019, 11, 18375–18381.

Research paper thumbnail of Bismuth oxide nanoparticles embedded carbon nanofibers as self-standing anode material for Na-ion batteries

Research paper thumbnail of The adsorption effect of freestanding SiOx-decorated stabilized polyacrylonitrile interlayers in lithium–sulfur batteries

Dalton Transactions

In this work, freestanding SiOx-decorated stabilized polyacrylonitrile interlayers were used with... more In this work, freestanding SiOx-decorated stabilized polyacrylonitrile interlayers were used with the aim of catching polysulfides and keeping them at the cathode side.

Research paper thumbnail of Freestanding oxidized poly(acrylonitrile-co-vinylpyrrolidone)/SnCl2 nanofibers as interlayer for Lithium Sulfur batteries

Research paper thumbnail of Rapid Microwave-Assisted Synthesis of Platinum Nanoparticles Immobilized in Electrospun Carbon Nanofibers for Electrochemical Catalysis

ACS Applied Nano Materials

Research paper thumbnail of DNA Directed Self-Assembly of Single Walled Carbon Nanotubes into Three-Way Junction Nanostructures

ACS omega, Jan 30, 2018

Utilization of a self-assembled two-dimensional DNA nanostructure to arrange single-walled carbon... more Utilization of a self-assembled two-dimensional DNA nanostructure to arrange single-walled carbon nanotubes (SWNTs) into predetermined structures at controllable angles is presented. A specially designed DNA three-way junction (3WJ) composed of three double-stranded DNA arms containing single-stranded overhang sequences was prepared by annealing of partially complementary ssDNA sequences and ultrasonicated with SWNTs, resulting in DNA-3WJ/SWNT hybrid nanostructures. Utilization of DNA-3WJ not only allowed the precise dispersion of SWNTs but also acted as a rigid template for the self-assembly of SWNTs into three-armed junctions at an angle of approximately 120° to each other as visualized by scanning electron microscopy and atomic force microscopy. Prepared DNA-3WJ/SWNT nanostructures were also demonstrated to have the appropriate binding sites for fluorophores, providing a simple method for the fluorescent labeling of SWNTs. When ssDNA sequences forming the DNA-3WJ are ultrasonicat...

Research paper thumbnail of Real-timeFTIR monitoring of the mechanism of initiation of isobutylene polymerizations by epoxide/Lewis acid systems

Real-time Fourier Transformation Infrared (FTIR) spectroscopy with a fiber optic transmission pro... more Real-time Fourier Transformation Infrared (FTIR) spectroscopy with a fiber optic transmission probe (TR) was used to monitor the polymerization of isobutylene (IB) initiated by a-methylstyrene epoxide (MSE) and 1,2-epoxi-2,4,4-trimethylpentane (TMPO-1) in conjunction with TiCl 4 and BCl 3. In the presence of an equimolar amount of BCl 3 , MSE and TMPO-1 underwent ring opening via S N 1 mechanism. In contrast to TiCl 4-coinitiated reactions, no oligoether formation via S N 2 mechanism was observed. TMPO-1 with excess BCl 3 initiated IB polymerization, yielding a telechelic PIB carrying a-primary OH and x-tertiary Cl functionalities with 70% initiator efficiency. V

Research paper thumbnail of Novel Epoxide Initiators for the Carbocationic Polymerization of Isobutylene

Macromolecular Symposia, 2011

ABSTRACT We recently reported the synthesis of polyisobutylene (PIB) via direct initiation by epo... more ABSTRACT We recently reported the synthesis of polyisobutylene (PIB) via direct initiation by epoxycyclohexyl isobutyl polyhedral oligomeric silsesquioxane (POSS®) (Figure 1) in conjunction with titanium tetrachloride (TiCl4). This system successfully initiated the living carbocationic polymerization of isobutylene (IB) in hexane/methyl chloride (Hx/MeCl -60/40, v/v) at T = −80 °C, yielding an asymmetric telechelic PIB with one POSS® cage head group and one tert-Cl end group.1 This paper will discuss IB polymerizations initiated by 1,2-epoxycyclohexane and bis[3,4-(epoxycyclohexyl)ethyl]-tetramethyl-disiloxane, in conjunction with TiCl4.

Research paper thumbnail of Biomimetic processes. IV. Carbocationic polymerization of isoprene initiated by dimethyl allyl alcohol

Journal of Polymer Science Part A-polymer Chemistry, 2009

In this article, we investigate a new bio-inspired synthetic route towards NR homologs based on t... more In this article, we investigate a new bio-inspired synthetic route towards NR homologs based on the carbocationic polymerization of isoprene initiated by dimethyl allyl alcohol (DMAOH)/TiCl4 or BF3.Et2O as the catalytic system. This study is the continuation of our studies related to the proof of principle that NR biosynthesis is based on a carbocationic mechanism. It is shown that using the biomimetic strategy of initiation by allylic carbocations, polyisoprene carrying a dimethyl allyl head group is produced almost exclusively via 1,4 addition, yielding repeating units with cis and trans configurations. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 2181–2189, 2009

Research paper thumbnail of Living carbocationic polymerization of isobutylene by epoxide /Lewis acid systems: The mechanism of initiation

PhDT, 2009

Living polymerization of isobutylene (IB) and subsequent controlled synthesis of ABA block copoly... more Living polymerization of isobutylene (IB) and subsequent controlled synthesis of ABA block copolymers, such as poly (styrene-b-isobutylene-b-styrene)(PSt-PIB-PSt) and poly (p-methylstyrene-b-isobutylene-bp-methylstyrene)(PpMeSt-PIB-PpMeSt), have been carried ...

Research paper thumbnail of <i>Real-time</i>FTIR monitoring of the mechanism of initiation of isobutylene polymerizations by epoxide/Lewis acid systems

Journal of Polymer Science Part A, Jun 1, 2008

ABSTRACT Real-time Fourier Transformation Infrared (FTIR) spectroscopy with a fiber optic transmi... more ABSTRACT Real-time Fourier Transformation Infrared (FTIR) spectroscopy with a fiber optic transmission probe (TR) was used to monitor the polymerization of isobutylene (IB) initiated by α-methylstyrene epoxide (MSE) and 1,2-epoxi-2,4,4-trimethylpentane (TMPO-1) in conjunction with TiCl4 and BCl3. In the presence of an equimolar amount of BCl3, MSE and TMPO-1 underwent ring opening via SN1 mechanism. In contrast to TiCl4-coinitiated reactions, no oligoether formation via SN2 mechanism was observed. TMPO-1 with excess BCl3 initiated IB polymerization, yielding a telechelic PIB carrying α-primary OH and ω-tertiary Cl functionalities with 70% initiator efficiency. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 3611–3618, 2008

Research paper thumbnail of Photothermal Electrospun Nanofibers Containing Polydopamine-Coated Halloysite Nanotubes as Antibacterial Air Filters

ACS Applied Nano Materials

Research paper thumbnail of Silicon nanocrystals-embedded carbon nanofibers from hybrid polyacrylonitrile – TEOS precursor as high-performance lithium-ion battery anodes

Journal of Alloys and Compounds, 2022

Research paper thumbnail of Specific Interactions and Self-Organization in Polymer/Functionalized Nanoparticle Systems

In this chapter, specific interactions and self-organization in nanocomposites containing functio... more In this chapter, specific interactions and self-organization in nanocomposites containing functionalized nanoparticles (NPs) are discussed. Common techniques applied for the synthesis, modification, and functionalization of inorganic NPs are summarized. The use of such NPs in the preparation of polymer-based nanocomposites and their effects on the structure–property relationships of the resulting materials are described by some representative studies reported in the literature. In particular, nanocomposites containing (1) modified silica NPs, (2) organically modified layered silicates, and (3) polyhedral oligomeric silsesquioxane (POSS) hybrids are addressed. Moreover, a general overview on the self-organization phenomenon is provided based on recent developments in the field of block copolymer-based nanocomposites.

Research paper thumbnail of Synthesis of POSS-Functionalized Polyisobutylene via Direct Initiation

Macromolecular Rapid Communications, 2009

Research paper thumbnail of Silicon-decorated carbon nanofibers as high-capacity and long-cycle life lithium-ion battery (LIB) anodes

Research paper thumbnail of Polymer Nanocomposites With Decorated Metal Oxides

Polymer Composites with Functionalized Nanoparticles, 2019

This chapter represents an overview of polymer nanocomposites containing functional metal oxide n... more This chapter represents an overview of polymer nanocomposites containing functional metal oxide nanoparticles as inorganic fillers. Metal oxide/polymer nanocomposites have received considerable attention as they are used in a wide range of applications in various fields including optoelectronic devices, biomedical applications, electromagnetic devices, optics, food packaging, photocatalysis, and many others. The desired properties of the nanocomposites could only be achieved with the good dispersion of nanostructures in the polymer matrix, which is difficult to achieve due to their specific surface area and volume effect. The surface engineered metal oxide nanoparticles overcome the aggregation problem providing improved interfacial interaction between the nanoparticles and the polymer matrix. Synthesis, surface functionalization, and nanocomposites of the metal oxide nanostructures as well as the properties and potential applications of the nanocomposites will be discussed this cha...

Research paper thumbnail of Living carbocationic polymerization of isobutylene by epoxide /Lewis acid systems: The mechanism of initiation

The objective of the work presented in this dissertation was to generate a fundamental understand... more The objective of the work presented in this dissertation was to generate a fundamental understanding of the synthesis of star-branched polyisobutylenes (PIBs) arising from hexaepoxysqualene (HES)/Lewis acid (LA) initiating systems, using BCl3 and TiCl4 as LAs. The understanding of initiation and propagation mechanisms by HES is crucial to control the number of arms and arm lengths of star PIBs expected from this initiator. The initiation by monofunctional epoxides, such as alpha-methylstyrene epoxide (MSE), 1,2-epoxy-2,4,4-trimethylpentane (TMPO-1), and 2,3-epoxy-2,4,4-trimethylpentane (TMPO-2), was investigated. In situ FTIR spectroscopy, which was highly utilized in this research, provided valuable information. Most importantly, the ability to identify the head group by in situ FTIR of growing PIB chains initiated by an epoxide, i.e. the --C--O--LA complex, contributed significantly to the understanding of initiation of IB polymerization. This technique allowed the monitoring of the rate of initiation with the multifunctional epoxy initiator. Previous research showed that TiCl4 gave 40% initiating efficiency in conjunction with the aromatic epoxy initiator MSE, whereas the aliphatic initiators TMPO-1 and TMPO-2 gave only 3 and 10% efficiency, respectively. In this research it was found that BCl3 is more efficient with the aliphatic initiator, TMPO-1, yielding an asymmetric telechelic PIB carrying an alpha-primary OH and an o-tertiary Cl functional group with 70% initiator efficiency, while MSE gave only 1--4% efficiency. The TMPO-2/BCl3 system gave 20% initiator efficiency. The various initiation mechanisms were discussed. IB polymerization was successfully initiated by HES in the presence of excess BCl3 and monitored by in situ FTIR spectroscopy. The gradual increase of the IR band assigned to the --C--O--BCl 2 group demonstrated that slow initiation was occurring. Chain extension with the HES/BCl3 initiated PIB was achieved leading to high molecular weight PIBs in the presence of TiCl4. It was also demonstrated for the first time that BCl3 invariably leads to beta-proton expulsion, leading to chain transfer in IB polymerization. In addition, 1,2-epoxycyclohexane and epoxycyclohexyl-functional siloxanes, i.e. epoxycyclohexylisobutyl polyhedral oligomeric silsesquioxane (POSS) and bis[3,4-(epoxycyclohexyl)ethyl]tetramethyldisiloxane, were found to be initiators for the polymerization of IB. 1,2-epoxycyclohexane/TiCl 4 was an efficient initiating system for the IB polymerization yielding up to 45% initiator efficiency. It was proposed that initiation of IB polymerization involves an SN2 reaction between IB and TiCl4-coordinated epoxide.

Research paper thumbnail of Mechanisms of Si Nanoparticle Formation by Molten Salt Magnesiothermic Reduction of Silica for Lithium‐ion Battery Anodes

Research paper thumbnail of One-pot synthesis of tin chalcogenide-reduced graphene oxide-carbon nanotube nanocomposite as anode material for lithium-ion batteries

Dalton Transactions

In this study, a ternary tin chalcogenide (TC)–reduced graphene oxide (RGO)–carbon nanotube (CNT)... more In this study, a ternary tin chalcogenide (TC)–reduced graphene oxide (RGO)–carbon nanotube (CNT) nanocomposite was synthesized as a lithium-ion battery (LIB) anode by a simple one-step protocol.

Research paper thumbnail of Correction: Capacitive behaviour of nanocrystalline octacalcium phosphate (OCP) (Ca8H2(PO4)6·5H2O) as an electrode material for supercapacitors: biosupercaps

Nanoscale

Correction for ‘Capacitive behaviour of nanocrystalline octacalcium phosphate (OCP) (Ca8H2(PO4)6·... more Correction for ‘Capacitive behaviour of nanocrystalline octacalcium phosphate (OCP) (Ca8H2(PO4)6·5H2O) as an electrode material for supercapacitors: biosupercaps’ by Mustafa Tuncer et al., Nanoscale, 2019, 11, 18375–18381.

Research paper thumbnail of Bismuth oxide nanoparticles embedded carbon nanofibers as self-standing anode material for Na-ion batteries

Research paper thumbnail of The adsorption effect of freestanding SiOx-decorated stabilized polyacrylonitrile interlayers in lithium–sulfur batteries

Dalton Transactions

In this work, freestanding SiOx-decorated stabilized polyacrylonitrile interlayers were used with... more In this work, freestanding SiOx-decorated stabilized polyacrylonitrile interlayers were used with the aim of catching polysulfides and keeping them at the cathode side.

Research paper thumbnail of Freestanding oxidized poly(acrylonitrile-co-vinylpyrrolidone)/SnCl2 nanofibers as interlayer for Lithium Sulfur batteries

Research paper thumbnail of Rapid Microwave-Assisted Synthesis of Platinum Nanoparticles Immobilized in Electrospun Carbon Nanofibers for Electrochemical Catalysis

ACS Applied Nano Materials

Research paper thumbnail of DNA Directed Self-Assembly of Single Walled Carbon Nanotubes into Three-Way Junction Nanostructures

ACS omega, Jan 30, 2018

Utilization of a self-assembled two-dimensional DNA nanostructure to arrange single-walled carbon... more Utilization of a self-assembled two-dimensional DNA nanostructure to arrange single-walled carbon nanotubes (SWNTs) into predetermined structures at controllable angles is presented. A specially designed DNA three-way junction (3WJ) composed of three double-stranded DNA arms containing single-stranded overhang sequences was prepared by annealing of partially complementary ssDNA sequences and ultrasonicated with SWNTs, resulting in DNA-3WJ/SWNT hybrid nanostructures. Utilization of DNA-3WJ not only allowed the precise dispersion of SWNTs but also acted as a rigid template for the self-assembly of SWNTs into three-armed junctions at an angle of approximately 120° to each other as visualized by scanning electron microscopy and atomic force microscopy. Prepared DNA-3WJ/SWNT nanostructures were also demonstrated to have the appropriate binding sites for fluorophores, providing a simple method for the fluorescent labeling of SWNTs. When ssDNA sequences forming the DNA-3WJ are ultrasonicat...

Research paper thumbnail of Real-timeFTIR monitoring of the mechanism of initiation of isobutylene polymerizations by epoxide/Lewis acid systems

Real-time Fourier Transformation Infrared (FTIR) spectroscopy with a fiber optic transmission pro... more Real-time Fourier Transformation Infrared (FTIR) spectroscopy with a fiber optic transmission probe (TR) was used to monitor the polymerization of isobutylene (IB) initiated by a-methylstyrene epoxide (MSE) and 1,2-epoxi-2,4,4-trimethylpentane (TMPO-1) in conjunction with TiCl 4 and BCl 3. In the presence of an equimolar amount of BCl 3 , MSE and TMPO-1 underwent ring opening via S N 1 mechanism. In contrast to TiCl 4-coinitiated reactions, no oligoether formation via S N 2 mechanism was observed. TMPO-1 with excess BCl 3 initiated IB polymerization, yielding a telechelic PIB carrying a-primary OH and x-tertiary Cl functionalities with 70% initiator efficiency. V

Research paper thumbnail of Novel Epoxide Initiators for the Carbocationic Polymerization of Isobutylene

Macromolecular Symposia, 2011

ABSTRACT We recently reported the synthesis of polyisobutylene (PIB) via direct initiation by epo... more ABSTRACT We recently reported the synthesis of polyisobutylene (PIB) via direct initiation by epoxycyclohexyl isobutyl polyhedral oligomeric silsesquioxane (POSS®) (Figure 1) in conjunction with titanium tetrachloride (TiCl4). This system successfully initiated the living carbocationic polymerization of isobutylene (IB) in hexane/methyl chloride (Hx/MeCl -60/40, v/v) at T = −80 °C, yielding an asymmetric telechelic PIB with one POSS® cage head group and one tert-Cl end group.1 This paper will discuss IB polymerizations initiated by 1,2-epoxycyclohexane and bis[3,4-(epoxycyclohexyl)ethyl]-tetramethyl-disiloxane, in conjunction with TiCl4.

Research paper thumbnail of Biomimetic processes. IV. Carbocationic polymerization of isoprene initiated by dimethyl allyl alcohol

Journal of Polymer Science Part A-polymer Chemistry, 2009

In this article, we investigate a new bio-inspired synthetic route towards NR homologs based on t... more In this article, we investigate a new bio-inspired synthetic route towards NR homologs based on the carbocationic polymerization of isoprene initiated by dimethyl allyl alcohol (DMAOH)/TiCl4 or BF3.Et2O as the catalytic system. This study is the continuation of our studies related to the proof of principle that NR biosynthesis is based on a carbocationic mechanism. It is shown that using the biomimetic strategy of initiation by allylic carbocations, polyisoprene carrying a dimethyl allyl head group is produced almost exclusively via 1,4 addition, yielding repeating units with cis and trans configurations. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 2181–2189, 2009