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Showing 1 to 20 of 54 for “"anionic polymerization"”.
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Anionic polymerization of a series of cyclocarbosiloxanes
<p>"A study has been made on the anionic polymerization of a series of cyclocarbosiloxanes of the type: [IMAGE] where n was varied from 2 to 8. The polymerization reaction in benzene, was initiated using cesium trihexyl silanolate, a unique organic soluble liquid catalysts. Benzene served as both a …
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Studies in the anionic polymerization of methyl methacrylate
A study has been made of the anionic polymerization of methyl methacrylate using butyllithium and polystyryl lithium as initiators and using aluminium triisobutyl as a cocatalyst. The aspects of the polymerization that were examined were the effect of changing the order of addition of reagents, the …
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Synthesis of novel methacrylate-containing polymers by anionic polymerization
The advent of anionic "living" polymerization in the late 1950’s lead to developments in synthetic control not yet approached by other polymerization mechanisms. Parameters such as molecular weight, molecular weight distribution, stereochemistry, chain end functional groups, polymer architecture …
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Polymers with complex architectures by convergent living anionic polymerization
Includes bibliographical references.
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Functional Block Copolymers via Anionic Polymerization for Electroactive Membranes
… macromolecular design. Conventional free radical polymerization and anion exchange achieved copolymers containing n-butyl acrylate and phosphonium ionic liquids. These compositions incorporated vinylbenzyl triphenyl phosphonium and vinylbenzyl tricyclohexyl phosphonium cations bearing chloride …
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Synthesis of Well-Defined Multi-End Functionalized Polymers via Living Anionic Polymerization
… the living chain ends of polymers prepared via anionic polymerization reactions. The resulting polymers have a well-defined structure with interesting surface modifying properties. We have also carried out hydrogenation of end functionalized polyisoprene to form poly(ethylene-alt-propylene) with …
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Investigations utilizing mono- and difunctional organo alkali metal initiators for anionic polymerization
… use of a difunctional organolithium as an anionic polymerization initiator for primarily diene monomers. The initiator was formed in nonpolar solvent such as cyclohexane and toluene by the addition of two equivalents of sec-butyllithium to one of the nonconjugated diene …
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From Block Copolymers to Crosslinked Networks: Anionic Polymerization Affords Functional Macromolecules for Advanced Technologies
… polymers using conventional free radical and anionic polymerization to incorporate ionic functionalities based on phosphonium cations. This new class of copolymers offers unique properties with ionic functionality for tailorable electro-active performance.
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Synthesis of novel siloxane-containing block and graft copolymers by anionic polymerization and the macromonomer technique
… backbone as well as the grafts are possible. The anionic alkyl- lithium initiated ring opening polymerization of the hexamethylcyclotrisiloxane has been investigated to prepare polymers of controlled molecular weights and narrow molecular weight distributions. This technique was extended to the …
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New block copolymers of Isobutylene by combination of cationic and anionic polymerizations
… of isobutylene by combination of cationic and anionic polymerizations, which are new materials with numerous promising potential applications. A new method for the synthesis of tailored polyisobutylene(PIB)-based block copolymer by combination of controlled / living cationic and anionic …
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Developing green processes for the conversion of biobased materials into pyrones
… <p>In the fourth chapter, we combined anionic polymerization with reversible addition fragmentation chain transfer RAFT polymerization by the development of macro-chain transfer agent. The conversion of anionic polystyrene to block acrylic copolymers had an efficiency as high as 97%. …
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Living Polymerization for the Introduction of Tailored Hydrogen Bonding
… in living anionic polymerization of isoprene was used to yield well-defined chain end functional macromolecules. Using both initiating systems, polymers with good molar mass control and narrow molar mass distributions were obtained and well-defined chain end …
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Self-Assembly, Spatial-, and Size- Control of Gold Nanoparticle/Block Copolymer Conjugates
… of 4VP were synthesized via sequential living anionic polymerization. Two different approaches of functionalized AuNP with S4VP polymers were exposed. Pyridylterminated polystyrenes were employed as monodentate ligands for AuNP, while longer blocks of 4VP were used as multidentate ligands. The …
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Synthesis and Characterization of Multiphase Block Copolymers: Influence of Functional Groups on Macromolecular Architecture
… repeating units were synthesized via anionic telomerization and conventional anionic polymerization. Maintaining the initiation and reaction temperature less than 70 °C minimized chain transfer and enabled the telomerization to occur in a living fashion, which resulted in …
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Doubly Bonded Derivatives of Si and Ge: Cycloaddition Reactions and Polymer Chemistry
… evidence for any rearrangement products and no polymerization was observed. The reactivity of the silene and germene toward organometallic reagents is compared to previous studies of analogous silenes and germenes. The characterization of polysilenes and polygermenes derived from the anionic …
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Studies Related to the Alternating Copolymerization of Substituted Stilbenes
… to understand the methyl substituent effect on copolymerization rates. Methyl substituted stilbene-maleic anhydride copolymer compositions were determined by quantitative ¹³C 1D NMR. SEC measurements showed the weight average molecular weights of these copolymers vary from 3 000 to over 1 000 000 …
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"Smart" Hydrogels based on Trishydrophilic Triblock Terpolymers
… aspect of this procedure, based on sequential anionic polymerization, was the utilization of the phosphazene base t-BuP4, enabling the anionic polymerization of epoxide monomers in the presence of lithium counterions. It was shown, that ethoxyethyl glycidyl ether polymerizes easily under the …
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Novel Approaches To The Synthesis of Clicked Block Copolymers
… properties. With the development of living polymerization techniques, the synthesis of block copolymers with controlled molecular weights and unique architectures has reached an all time high. Here a novel approach to the synthesis of block copolymers, namely polystyrene-b-polyisoprene, …
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Order in side-chain liquid crystalline diblock copolymers
… a wide array of applications. Using sequential anionic polymerization we synthesized a large number of well-defined SCLCBC's. These materials consist of an amorphous, polystyrene (PS) block and a methacrylate-based, LC block with side-chain mesogens that exhibit the Sc* mesophase. The samples' …
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Anionic synthesis and characterization of alkyl methacrylate containing polymeric systems
The anionic synthesis of alkyl methacrylates has received sparse attention in comparison to the synthesis of nonpolar hydrocarbon monomers such as styrene or the dienes. The two major reasons for the sluggish synthetic development of this class of polar monomers are the protic impurities present in …
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