The Experts below are selected from a list of 60 Experts worldwide ranked by ideXlab platform
Shadpour Mallakpour - One of the best experts on this subject based on the ideXlab platform.
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Condensation Polymer layered double hydroxide ncs preparation characterization and utilizations
European Polymer Journal, 2017Co-Authors: Shadpour Mallakpour, Masoud HatamiAbstract:Abstract Recently nanocomposites (NCs) based on layered double hydroxide (LDH) and Condensation Polymers have attracted a huge deal of attention; because these compounds offer a great and important potential to provide grander behaviors in contrast to uncombined materials. These materials demonstrate good properties such as great heat deflection temperature, great dimensional stability, cheap gas absorbency, enhance in thermal, flame retardancy, and mechanical properties. Such enhancements happen due to interfacial effects resulting from uniform and homogenous dispersion of great aspect ratio LDH nanofillers in Condensation Polymeric matrixes, and of their tunable behaviors of LDHs. This review provides a summary of Condensation Polymers with LDH incorporated NCs and characterization of these NCs by morphological, mechanical, thermal and barrier properties, flame retardancy, and reduced gas permeability in contrast to the neat Polymeric matrix. So, at first, a summary of the basic structure and how to modification of LDH nanofillers will be presented, then, the potential applications of LDH nanofillers incorporation in Condensation Polymers matrix and the effects of them on the properties of NCs will be briefly discussed.
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Condensation Polymer/layered double hydroxide NCs: Preparation, characterization, and utilizations
European Polymer Journal, 2017Co-Authors: Shadpour Mallakpour, Masoud HatamiAbstract:Abstract Recently nanocomposites (NCs) based on layered double hydroxide (LDH) and Condensation Polymers have attracted a huge deal of attention; because these compounds offer a great and important potential to provide grander behaviors in contrast to uncombined materials. These materials demonstrate good properties such as great heat deflection temperature, great dimensional stability, cheap gas absorbency, enhance in thermal, flame retardancy, and mechanical properties. Such enhancements happen due to interfacial effects resulting from uniform and homogenous dispersion of great aspect ratio LDH nanofillers in Condensation Polymeric matrixes, and of their tunable behaviors of LDHs. This review provides a summary of Condensation Polymers with LDH incorporated NCs and characterization of these NCs by morphological, mechanical, thermal and barrier properties, flame retardancy, and reduced gas permeability in contrast to the neat Polymeric matrix. So, at first, a summary of the basic structure and how to modification of LDH nanofillers will be presented, then, the potential applications of LDH nanofillers incorporation in Condensation Polymers matrix and the effects of them on the properties of NCs will be briefly discussed.
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Advances in synthetic optically active Condensation Polymers - A review
Express Polymer Letters, 2011Co-Authors: Shadpour Mallakpour, Amin Zadehnazari, I. R. IranAbstract:The study of optically active Polymers is a very active research field, and these materials have exhibited a num- ber of interesting properties. Much of the attention in chiral Polymers results from the potential of these materials for sev- eral specialized utilizations that are chiral matrices for asymmetric synthesis, chiral stationary phases for the separation of racemic mixtures, synthetic molecular receptors and chiral liquid crystals for ferroelectric and nonlinear optical applica- tions. Recently, highly efficient methodologies and catalysts have been developed to synthesize various kinds of optically active compounds. Some of them can be applied to chiral Polymer synthesis. In a few synthetic approaches for optically active Polymers, chiral monomer Polymerization has essential advantages in applicability of monomer, apart from both asymmetric Polymerization of achiral or prochiral monomers and enantioselective Polymerization of a racemic monomer mixture. The following are the up to date successful approaches to the chiral synthetic Polymers by Condensation Polymer- ization reaction of chiral monomers.
Masoud Hatami - One of the best experts on this subject based on the ideXlab platform.
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Condensation Polymer layered double hydroxide ncs preparation characterization and utilizations
European Polymer Journal, 2017Co-Authors: Shadpour Mallakpour, Masoud HatamiAbstract:Abstract Recently nanocomposites (NCs) based on layered double hydroxide (LDH) and Condensation Polymers have attracted a huge deal of attention; because these compounds offer a great and important potential to provide grander behaviors in contrast to uncombined materials. These materials demonstrate good properties such as great heat deflection temperature, great dimensional stability, cheap gas absorbency, enhance in thermal, flame retardancy, and mechanical properties. Such enhancements happen due to interfacial effects resulting from uniform and homogenous dispersion of great aspect ratio LDH nanofillers in Condensation Polymeric matrixes, and of their tunable behaviors of LDHs. This review provides a summary of Condensation Polymers with LDH incorporated NCs and characterization of these NCs by morphological, mechanical, thermal and barrier properties, flame retardancy, and reduced gas permeability in contrast to the neat Polymeric matrix. So, at first, a summary of the basic structure and how to modification of LDH nanofillers will be presented, then, the potential applications of LDH nanofillers incorporation in Condensation Polymers matrix and the effects of them on the properties of NCs will be briefly discussed.
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Condensation Polymer/layered double hydroxide NCs: Preparation, characterization, and utilizations
European Polymer Journal, 2017Co-Authors: Shadpour Mallakpour, Masoud HatamiAbstract:Abstract Recently nanocomposites (NCs) based on layered double hydroxide (LDH) and Condensation Polymers have attracted a huge deal of attention; because these compounds offer a great and important potential to provide grander behaviors in contrast to uncombined materials. These materials demonstrate good properties such as great heat deflection temperature, great dimensional stability, cheap gas absorbency, enhance in thermal, flame retardancy, and mechanical properties. Such enhancements happen due to interfacial effects resulting from uniform and homogenous dispersion of great aspect ratio LDH nanofillers in Condensation Polymeric matrixes, and of their tunable behaviors of LDHs. This review provides a summary of Condensation Polymers with LDH incorporated NCs and characterization of these NCs by morphological, mechanical, thermal and barrier properties, flame retardancy, and reduced gas permeability in contrast to the neat Polymeric matrix. So, at first, a summary of the basic structure and how to modification of LDH nanofillers will be presented, then, the potential applications of LDH nanofillers incorporation in Condensation Polymers matrix and the effects of them on the properties of NCs will be briefly discussed.
Sangdeok Shim - One of the best experts on this subject based on the ideXlab platform.
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New Condensation Polymer Precursors Containing Consecutive Silicon Atoms-Decaisopropoxycyclopentasilane and Dodecaethoxyneopentasilane-And Their Sol⁻Gel Polymerization.
Polymers, 2019Co-Authors: Sung Jin Park, Myong Euy Lee, Hyeon Mo Cho, Sangdeok ShimAbstract:The sol-gel Polymerization of alkoxysilanes is a convenient and widely used method for the synthesis of silicon Polymers and silicon-organic composites. The development of new sol-gel precursors is very important for obtaining new types of sol-gel products. New Condensation Polymer precursors containing consecutive silicon atoms-decaisopropoxycyclopentasilane (CPS) and dodecaethoxyneopentasilane (NPS)-were synthesized for the preparation of polysilane-polysiloxane material. The CPS and NPS xerogels were prepared by the sol-gel Polymerization of CPS and NPS under three reaction conditions (acidic, basic and neutral). The CPS and NPS xerogels were characterized using N2 physisorption measurements (Brunauer-Emmett-Teller; BET and Brunauer-Joyner-Halenda; BJH), solid-state CP/MAS (cross-polarization/magic angle spinning) NMRs (nuclear magnetic resonances), TEM, and SEM. Their porosity and morphology were strongly affected by the structure of the precursors, and partial oxidative cleavage of Si-Si bonds occurred during the sol-gel process. The new Condensation Polymer precursors are expected to expand the choice of approaches for new polysilane-polysiloxane.
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New Condensation Polymer Precursors Containing Consecutive Silicon Atoms—Decaisopropoxycyclopentasilane and Dodecaethoxyneopentasilane—And Their Sol–Gel Polymerization
MDPI AG, 2019Co-Authors: Sung Jin Park, Myong Euy Lee, Hyeon Mo Cho, Sangdeok ShimAbstract:The sol−gel Polymerization of alkoxysilanes is a convenient and widely used method for the synthesis of silicon Polymers and silicon−organic composites. The development of new sol−gel precursors is very important for obtaining new types of sol−gel products. New Condensation Polymer precursors containing consecutive silicon atoms—decaisopropoxycyclopentasilane (CPS) and dodecaethoxyneopentasilane (NPS)—were synthesized for the preparation of polysilane−polysiloxane material. The CPS and NPS xerogels were prepared by the sol−gel Polymerization of CPS and NPS under three reaction conditions (acidic, basic and neutral). The CPS and NPS xerogels were characterized using N2 physisorption measurements (Brunauer−Emmett−Teller; BET and Brunauer-Joyner-Halenda; BJH), solid-state CP/MAS (cross-polarization/magic angle spinning) NMRs (nuclear magnetic resonances), TEM, and SEM. Their porosity and morphology were strongly affected by the structure of the precursors, and partial oxidative cleavage of Si-Si bonds occurred during the sol−gel process. The new Condensation Polymer precursors are expected to expand the choice of approaches for new polysilane−polysiloxane
Akihiro Yokoyama - One of the best experts on this subject based on the ideXlab platform.
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Chain-growth polyCondensation for well-defined Condensation Polymers and Polymer architecture.
Chemical record (New York N.Y.), 2005Co-Authors: Tsutomu Yokozawa, Akihiro YokoyamaAbstract:The historical development of our research on polyCondensation that proceeds in a chain-growth Polymerization manner (“chain-growth polyCondensation”) for well-defined Condensation Polymers is described. We first studied polyCondensation in which change of the substituent effect induced by bond formation drove the reactivity of the Polymer end group higher than that of the monomer. In this approach, well-defined aromatic polyamides, polyesters, polyethers, and poly(ether sulfone)s were obtained. The second approach was the study of the phase-transfer Polymerization of a solid monomer dispersed in an organic solvent. In this type of Polymerization, the solid monomer was physically unable to react with another monomer and was carried with the phase transfer catalyst into the solution phase where it reacted with an initiator and the Polymer end group in the solvent in a chain Polymerization manner. We also found catalyst-transfer polyCondensation as a third approach to chain-growth polyCondensation. In the Ni-catalyzed polyCondensation of 2-bromo-5-chloromagnesiothiophenes, the Ni catalyst transferred to the Polymer end group, and a coupling reaction occurred there to yield a well-defined polythiophene. This chain-growth polyCondensation was applied to the synthesis of Condensation Polymer architectures such as block coPolymers, star Polymers, graft coPolymers, and so on. © 2005 The Japan Chemical Journal Forum and Wiley Periodicals, Inc. Chem Rec 5: 47–57; 2005: Published online in Wiley InterScience (www.interscience.wiley.com) DOI 10.1002/tcr.20032
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chain growth polyCondensation for well defined Condensation Polymers and Polymer architecture
Chemical Record, 2005Co-Authors: Tsutomu Yokozawa, Akihiro YokoyamaAbstract:The historical development of our research on polyCondensation that proceeds in a chain-growth Polymerization manner ("chain-growth polyCondensation") for well-defined Condensation Polymers is described. We first studied polyCondensation in which change of the substituent effect induced by bond formation drove the reactivity of the Polymer end group higher than that of the monomer. In this approach, well-defined aromatic polyamides, polyesters, polyethers, and poly(ether sulfone)s were obtained. The second approach was the study of the phase-transfer Polymerization of a solid monomer dispersed in an organic solvent. In this type of Polymerization, the solid monomer was physically unable to react with another monomer and was carried with the phase transfer catalyst into the solution phase where it reacted with an initiator and the Polymer end group in the solvent in a chain Polymerization manner. We also found catalyst-transfer polyCondensation as a third approach to chain-growth polyCondensation. In the Ni-catalyzed polyCondensation of 2-bromo-5-chloromagnesiothiophenes, the Ni catalyst transferred to the Polymer end group, and a coupling reaction occurred there to yield a well-defined polythiophene. This chain-growth polyCondensation was applied to the synthesis of Condensation Polymer architectures such as block coPolymers, star Polymers, graft coPolymers, and so on.
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Chain-Growth PolyCondensation: Living Polymerization Nature in PolyCondensation and Approach to Condensation Polymer Architecture
Polymer Journal, 2004Co-Authors: Tsutomu Yokozawa, Akihiro YokoyamaAbstract:In this review article, polyCondensation that proceeds in a chain-growth Polymerization manner (“chain-growth polyCondensation”) for well-defined Condensation Polymers are described. Our approach to chain-growth polyCondensation is (1) activation of Polymer end group by substituent effects changed between monomer and Polymer and (2) phase-transfer Polymerization in biphase composed of monomer store phase and Polymerization phase. In the approach (1), a variety of Condensation Polymers such as aromatic polyamides, aromatic polyesters, aromatic polyethers, poly(ether sulfone), and polythiophene with defined molecular weights and low polydispersities were obtained. Their polyCondensations had all of the characteristics of living Polymerization: a linear correlation between molecular weights and monomer conversion maintaining low polydispersities, and control over molecular weights by the feed ratio of monomer to initiator. Taking advantage of the nature of living Polymerization in this polyCondensation, we synthesized diblock coPolymers of different kinds of aromatic polyamides and of aromatic polyamide and conventional Polymers such as poly(ethylene glycol), polystyrene, and poly(tetrahydrofuran), as well as triblock coPolymers and star Polymers containing aromatic polyamide units. Some coPolymers were arranged in a supramolecular self-assembly. In the approach (2), the polyCondensation of solid monomer dispersed in organic solvent with a phase transfer catalyst (PTC) was carried out, where solid monomer did not react with each other, and the monomer transferred to organic solvent with PTC reacted with an initiator and the Polymer end group selectively in organic solvent, to yield well-defined polyesters.
Tsutomu Yokozawa - One of the best experts on this subject based on the ideXlab platform.
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Chain-growth polyCondensation for well-defined Condensation Polymers and Polymer architecture.
Chemical record (New York N.Y.), 2005Co-Authors: Tsutomu Yokozawa, Akihiro YokoyamaAbstract:The historical development of our research on polyCondensation that proceeds in a chain-growth Polymerization manner (“chain-growth polyCondensation”) for well-defined Condensation Polymers is described. We first studied polyCondensation in which change of the substituent effect induced by bond formation drove the reactivity of the Polymer end group higher than that of the monomer. In this approach, well-defined aromatic polyamides, polyesters, polyethers, and poly(ether sulfone)s were obtained. The second approach was the study of the phase-transfer Polymerization of a solid monomer dispersed in an organic solvent. In this type of Polymerization, the solid monomer was physically unable to react with another monomer and was carried with the phase transfer catalyst into the solution phase where it reacted with an initiator and the Polymer end group in the solvent in a chain Polymerization manner. We also found catalyst-transfer polyCondensation as a third approach to chain-growth polyCondensation. In the Ni-catalyzed polyCondensation of 2-bromo-5-chloromagnesiothiophenes, the Ni catalyst transferred to the Polymer end group, and a coupling reaction occurred there to yield a well-defined polythiophene. This chain-growth polyCondensation was applied to the synthesis of Condensation Polymer architectures such as block coPolymers, star Polymers, graft coPolymers, and so on. © 2005 The Japan Chemical Journal Forum and Wiley Periodicals, Inc. Chem Rec 5: 47–57; 2005: Published online in Wiley InterScience (www.interscience.wiley.com) DOI 10.1002/tcr.20032
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chain growth polyCondensation for well defined Condensation Polymers and Polymer architecture
Chemical Record, 2005Co-Authors: Tsutomu Yokozawa, Akihiro YokoyamaAbstract:The historical development of our research on polyCondensation that proceeds in a chain-growth Polymerization manner ("chain-growth polyCondensation") for well-defined Condensation Polymers is described. We first studied polyCondensation in which change of the substituent effect induced by bond formation drove the reactivity of the Polymer end group higher than that of the monomer. In this approach, well-defined aromatic polyamides, polyesters, polyethers, and poly(ether sulfone)s were obtained. The second approach was the study of the phase-transfer Polymerization of a solid monomer dispersed in an organic solvent. In this type of Polymerization, the solid monomer was physically unable to react with another monomer and was carried with the phase transfer catalyst into the solution phase where it reacted with an initiator and the Polymer end group in the solvent in a chain Polymerization manner. We also found catalyst-transfer polyCondensation as a third approach to chain-growth polyCondensation. In the Ni-catalyzed polyCondensation of 2-bromo-5-chloromagnesiothiophenes, the Ni catalyst transferred to the Polymer end group, and a coupling reaction occurred there to yield a well-defined polythiophene. This chain-growth polyCondensation was applied to the synthesis of Condensation Polymer architectures such as block coPolymers, star Polymers, graft coPolymers, and so on.
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Chain-Growth PolyCondensation: Living Polymerization Nature in PolyCondensation and Approach to Condensation Polymer Architecture
Polymer Journal, 2004Co-Authors: Tsutomu Yokozawa, Akihiro YokoyamaAbstract:In this review article, polyCondensation that proceeds in a chain-growth Polymerization manner (“chain-growth polyCondensation”) for well-defined Condensation Polymers are described. Our approach to chain-growth polyCondensation is (1) activation of Polymer end group by substituent effects changed between monomer and Polymer and (2) phase-transfer Polymerization in biphase composed of monomer store phase and Polymerization phase. In the approach (1), a variety of Condensation Polymers such as aromatic polyamides, aromatic polyesters, aromatic polyethers, poly(ether sulfone), and polythiophene with defined molecular weights and low polydispersities were obtained. Their polyCondensations had all of the characteristics of living Polymerization: a linear correlation between molecular weights and monomer conversion maintaining low polydispersities, and control over molecular weights by the feed ratio of monomer to initiator. Taking advantage of the nature of living Polymerization in this polyCondensation, we synthesized diblock coPolymers of different kinds of aromatic polyamides and of aromatic polyamide and conventional Polymers such as poly(ethylene glycol), polystyrene, and poly(tetrahydrofuran), as well as triblock coPolymers and star Polymers containing aromatic polyamide units. Some coPolymers were arranged in a supramolecular self-assembly. In the approach (2), the polyCondensation of solid monomer dispersed in organic solvent with a phase transfer catalyst (PTC) was carried out, where solid monomer did not react with each other, and the monomer transferred to organic solvent with PTC reacted with an initiator and the Polymer end group selectively in organic solvent, to yield well-defined polyesters.