The Experts below are selected from a list of 216 Experts worldwide ranked by ideXlab platform
Shuji Okada - One of the best experts on this subject based on the ideXlab platform.
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Solid-State Polymerization of 1,4-bis(hexatriynyl)benzene derivatives
Polymer Journal, 2018Co-Authors: Keita Sasamura, Yoko Tatewaki, Kei Mizuguchi, Shuji OkadaAbstract:Two 1,4-bis(hexatriynyl)benzene derivatives with urethane groups, i.e., 10,10′-(1,4-phenylene)bis(5,7,9-decatriynyl N -(butoxycarbonylmethyl)carbamate) 1 and its perfluorophenylene derivative 2 , were synthesized, and their Solid-State photoPolymerization was investigated. Upon UV irradiation, both of them showed excitonic absorption characteristic of polydiacetylene (PDA). In particular, 2 showed an absorption maximum at 743 nm, which was approximately 100 nm longer than that of conventional PDAs because of the effective conjugation between the polymer backbone and π-conjugated substituents. The conversion of 1 to the corresponding polymer was quite low. On the other hand, more than half of the hexatriynyl moieties of 2 were found to polymerize, indicating that most of the monomers were converted to the polymer upon prolonged UV irradiation. 10,10′-(1,4-Phenylene)bis(5,7,9-decatriynyl N -(butoxycarbonylmethyl)carbamate) 1 and its perfluorophenylene derivative 2 were synthesized. Upon UV irradiation, both of them showed excitonic absorption of polydiacetylene. In particular, 2 showed an absorption maximum at 743 nm, which was approximately 100 nm longer than that of conventional polydiacetylenes, and its Solid-State Polymerization scheme was investigated.
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thermal Solid State Polymerization of a divalent metal salt of an unsaturated carboxylic acid and the effects of additives
Polymer Journal, 2013Co-Authors: Junki Tsuchida, Shuji Okada, Yoko Tatewaki, Satoshi Inayama, Yosuke Saito, Saki Sato, Ushio Yuki, Ayaka Shindo, Chiemi Mikura, Kazuhisa FushiharaAbstract:Thermal Solid-State Polymerization of zinc diacrylate (ZDA) alone and with additives, such as diphenyl disulfide (DPDS) and thiophenol (TP) derivatives and dicumyl peroxide (DCP), was investigated. The Solid-State Polymerization of ZDA was confirmed to be non-topochemical, and the main polymer structure was found to be polyacrylate with acrylate or polyacrylate connected by Zn2+ although a part of the monomer structure was eliminated during the Polymerization. The Polymerization rates were estimated by conversion from ZDA to its polymer, which was determined gravimetrically. The qualitative order of the Polymerization rate was ZDA
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Thermal Solid-State Polymerization of a divalent metal salt of an unsaturated carboxylic acid and the effects of additives
Polymer Journal, 2013Co-Authors: Junki Tsuchida, Shuji Okada, Yoko Tatewaki, Satoshi Inayama, Yosuke Saito, Saki Sato, Ushio Yuki, Ayaka Shindo, Chiemi Mikura, Kazuhisa FushiharaAbstract:Thermal Solid-State Polymerization of zinc diacrylate (ZDA) alone and with additives, such as diphenyl disulfide (DPDS) and thiophenol (TP) derivatives and dicumyl peroxide (DCP), was investigated. The Solid-State Polymerization of ZDA was confirmed to be non-topochemical, and the main polymer structure was found to be polyacrylate with acrylate or polyacrylate connected by Zn^2+ although a part of the monomer structure was eliminated during the Polymerization. The Polymerization rates were estimated by conversion from ZDA to its polymer, which was determined gravimetrically. The qualitative order of the Polymerization rate was ZDA
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Radical-initiator-Induced Solid-State Polymerization of butadiyne nanocrystals in water and their dispersion stabilization.
Journal of Nanoscience and Nanotechnology, 2011Co-Authors: Shuhei Kato, Takahiro Kinemuchi, Akito Masuhara, Shuji Okada, Yoko Tatewaki, Hitoshi Kasai, Hidetoshi OikawaAbstract:: Butadiyne nanocrystals in water are usually polymerized by UV or gamma-ray irradiation to give polydiacetylene (PDA) nanocrystals. In this study, we confirmed that Solid-State Polymerization of 1,6-di(N-carbazolyl)-2,4-hexadiyne (DCHD) and 5,7-dodecadiyn-1,12-diyl bis[N-(butoxycarbonyl-methyl)carbamate] (4BCMU) could be stimulated by water-soluble radical initiators. The radical initiators used were potassium peroxodisulfate, three kinds of azo-type compounds and a redox initiator. In all cases, the Solid-State Polymerization was confirmed by color change into blue indicating that PDA modified by the radical residues at the end was formed. However, nanocrystal cohesion occurred especially when the concentration of the initiators was high or the dispersion was kept for a long time. In order to improve the dispersion stability, two kinds of surfactants, i.e., sodium dodecyl sulfate (SDS) or dodecyltrimethylammonium chloride (DTMAC), were added to the DCHD nanocrystal aqueous dispersion. As a result, when anionic SDS was added, the Solid-State Polymerization of nanocrystals proceeded without coagulation and quantitative conversion was confirmed for all initiators. Cationic DTMAC has no effect on dispersion stabilization. PDA nanocrystal surfaces in water are negatively charged in nature and electric interaction of nanocrystals with the cations results in decrease of surface charge and aggregation of nanocrystals.
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Solid-State Polymerization of conjugated hexayne derivatives with different end groups
Polymer Journal, 2010Co-Authors: Satoshi Inayama, Yoko Tatewaki, Shuji OkadaAbstract:10,12,14,16,18,20-Triacontahexayne-1,30-diol and its diphenylurethane and diphenylester were synthesized, and their Solid-State Polymerization behaviors were investigated. The regular two-step Solid-State Polymerization was confirmed for the diphenylurethane derivative. Three hexayne derivatives with different end groups—that is, 10,12,14,16,18,20-triacontahexayne-1,30-diol ( 1 ) and its diphenylurethane ( 2 ) and diphenylester ( 3 )—were synthesized, and their Solid-State Polymerization behaviors were investigated. All three monomers were thermally polymerizable. Polymers from 1 and 2 showed an absorption maximum at about 730 nm, indicating that linear polydiacetylenes (PDAs) with octatetraynyl substituents were synthesized. However, broad absorption bands in the near-infrared region were only observed for 2 at 980 and 860 nm, indicating that regular Polymerization occurred in 2 to give ladder-type PDA. On the other hand, a polymer from 3 showed a visible absorption increase but no clear absorption maximum. It was estimated that intermolecular hydrogen bonding between hexayne monomers helps to form polymerizable stacks in 1 and 2 . In particular, urethane groups are more effective, and 2 showed the highest reactivity in this study with an ordered interlayer structure even after a two-step Solid-State Polymerization to give ladder-type PDA.
Kazuhisa Fushihara - One of the best experts on this subject based on the ideXlab platform.
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thermal Solid State Polymerization of a divalent metal salt of an unsaturated carboxylic acid and the effects of additives
Polymer Journal, 2013Co-Authors: Junki Tsuchida, Shuji Okada, Yoko Tatewaki, Satoshi Inayama, Yosuke Saito, Saki Sato, Ushio Yuki, Ayaka Shindo, Chiemi Mikura, Kazuhisa FushiharaAbstract:Thermal Solid-State Polymerization of zinc diacrylate (ZDA) alone and with additives, such as diphenyl disulfide (DPDS) and thiophenol (TP) derivatives and dicumyl peroxide (DCP), was investigated. The Solid-State Polymerization of ZDA was confirmed to be non-topochemical, and the main polymer structure was found to be polyacrylate with acrylate or polyacrylate connected by Zn2+ although a part of the monomer structure was eliminated during the Polymerization. The Polymerization rates were estimated by conversion from ZDA to its polymer, which was determined gravimetrically. The qualitative order of the Polymerization rate was ZDA
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Thermal Solid-State Polymerization of a divalent metal salt of an unsaturated carboxylic acid and the effects of additives
Polymer Journal, 2013Co-Authors: Junki Tsuchida, Shuji Okada, Yoko Tatewaki, Satoshi Inayama, Yosuke Saito, Saki Sato, Ushio Yuki, Ayaka Shindo, Chiemi Mikura, Kazuhisa FushiharaAbstract:Thermal Solid-State Polymerization of zinc diacrylate (ZDA) alone and with additives, such as diphenyl disulfide (DPDS) and thiophenol (TP) derivatives and dicumyl peroxide (DCP), was investigated. The Solid-State Polymerization of ZDA was confirmed to be non-topochemical, and the main polymer structure was found to be polyacrylate with acrylate or polyacrylate connected by Zn^2+ although a part of the monomer structure was eliminated during the Polymerization. The Polymerization rates were estimated by conversion from ZDA to its polymer, which was determined gravimetrically. The qualitative order of the Polymerization rate was ZDA
Constantine D. Papaspyrides - One of the best experts on this subject based on the ideXlab platform.
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Solid State Polymerization of poly lactic acid some fundamental parameters
Polymer Degradation and Stability, 2013Co-Authors: Stamatina Vouyiouka, Constantine D. Papaspyrides, Pavlos Theodoulou, Antonia Symeonidou, Rudolf PfaendnerAbstract:Abstract Poly(lactic acid) (PLA) was submitted to Solid State Polymerization (SSP) in a fixed bed reactor under nitrogen flow, so as to examine technique efficiency for increasing the molecular weight and hence permitting the reduction of the melt Polymerization residence times. In order to use a suitable starting material, SSP prepolymers of low and medium molecular weight were first prepared through Solid State hydrolysis of commercial PLA grade under acidic and alkaline conditions. During these degradation runs, hydrolysis involved the random scission of ester groups in the polymer backbone, while the relevant kinetics and the resulting thermal properties were also examined. In a subsequent step, the prepolymers obtained were subjected to SSP at three temperatures, approximately 2.5–25.0 °C below their melting point. The process achieved an increase of up to 1.7 times the initial molecular weight, however, with different trends depending on the prepolymer characteristics, reaction temperature and time, as well as the pH of the hydrolysis medium. In addition to molecular weight build up, the effect of the SSP process on end product thermal properties was also investigated.
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Nanocatalysis in Polyamide 6.6 Solid‐State Polymerization
Macromolecular Materials and Engineering, 2010Co-Authors: Anastasia C. Boussia, Stamatina Vouyiouka, Maria O. Konstantakopoulou, Constantine D. PapaspyridesAbstract:Solid-State Polymerization (SSP) of a poly(hexamethyleneadipamide) (PA 6.6)/clay nanocomposite system was studied. SSP runs were performed in a fixed-bed reactor, at temperatures 160–200 °C and reaction times up to 8 h. The influence of clay presence on the PA 6.6 SSP rate constant was herewith quantified for the first time to prove significant acceleration of the SSP process. A catalysis mechanism was suggested, according to which the positive effect of clay is of a synergistic origin attributed to nucleated crystal morphology, that increased the concentration of reactive end groups in the amorphous regions, to chain extension performed by clay SiOH groups, and to thermal protection of the polyamide matrix due to the presence of the nanoparticles.
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Solid State Polymerization
2009Co-Authors: Constantine D. Papaspyrides, Stamatina VouyioukaAbstract:Contributors. Preface. 1 Fundamentals of Solid State Polymerization ( C. D. Papaspyrides and S. N. Vouyiouka ). 1.1 Introduction. 1.2 Solid State Polymerization of Chain-Growth Polymers (Solid State Polyaddition). 1.3 Solid State Polymerization of Step-Growth Polymers (Solid State Polycondensation). 1.4 Solid State Polymerization Apparatus and Assemblies. 1.5 Solid State Applications in the Polymer Industry. 1.6 Conclusions. 2 Solid State Polymerization Chemistry and Mechanisms: Unequal Reactivity of End Groups ( Haibing Zhang and Saleh A. Jabarin ). 2.1 Introduction. 2.2 Special Characteristics of Solid State Polymerization. 2.3 Classical Kinetic Equations in Solid State Polymerization. 2.4 Model of Molecular Morphology and Chain-End Movement. 2.5 Reactivity of End Groups. 2.6 Why Intrinsic Viscosity Levels Off During Solid State Polymerization. 2.7 Solid State Polymerization Kinetics. 2.8 Conclusions. 3 Kinetic Aspects of Polyester Solid State Polymerization ( F. Pilati and M. Toselli ). 3.1 Introduction. 3.2 Phenomena Involved in Solid State Polymerization of Polyesters. 3.3 Modeling Solid State Polymerization of Polyesters. 3.4 Solid State Polymerization of Typical Polyesters. 3.5 Conclusions. 4 Kinetic Aspects of Polyamide Solid State Polymerization ( S. N. Vouyiouka and C. D. Papaspyrides ). 4.1 Introduction. 4.2 Simple Kinetic Models of Solid State Polyamidation. 4.3 Simulation of Solid State Polyamidation. 4.4 Simple SSP Kinetics: The Case of Poly(hexamethylene adipamide). 4.5 Conclusions. 5 Catalysis in Solid State Polymerization Processes ( Rudolf Pfaendner ). 5.1 Introduction. 5.2 Catalysts in Polyester Solid State Polymerization Processes. 5.3 Catalysts in Polyamide Solid State Polymerization Processes. 5.4 Reactive Additives in Solid State Polymerization Processes. 5.5 Inert Additives in Solid State Polymerization Processes. 5.6 Conclusions. 6 High-Pressure Solid State Polymerization of Polyamide Monomer Crystals ( Tokimitsu Ikawa ). 6.1 Introduction. 6.2 High-Pressure Solid State Polymerization. 6.2.1 Crystals and Characteristics of Monomers. 6.3 Polymerizability and Structure Formation. 6.4 Conclusions. 7 Fundamental Process Modeling and Product Design for the Solid State Polymerization of Polyamide 6 and Poly(ethylene terephthalate) ( Kevin C. Seavey and Y. A. Liu ). 7.1 Introduction. 7.2 Solid State Polymerization Modeling Guide. 7.3 Fundamentals of Solid State Polymerization Reactors. 7.4 Numerical Solution. 7.5 Example Simulation and Application. 7.6 Modifications to Account for Crystallization. 7.7 Conclusions. 8 Recent Developments in Solid State Polymerization of Poly(ethylene terephthalate) ( S. A. Wadekar, U. S. Agarwal, W. H. Boon, and V. M. Nadkarni ). 8.1 Introduction. 8.2 Conventional Solid State Polymerization Processes. 8.3 New Solid State Polymerization Processes. 8.4 Poly(ethylene terephthalate) Flake Recycling Using Solid State Polymerization. 8.5 Particle Formation Technologies. 8.6 Alternatives to Solid State Polymerization. 8.7 Poly(ethylene terephthalate) for Fluid Packaging Applications. 8.8 Conclusions. Abbreviations and Symbols. Index.
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Comprar Solid State Polymerization | Allan Tasman | 9780470084182 | Wiley
2009Co-Authors: Allan Tasman, Constantine D. Papaspyrides, Jerald Kay, Jeffrey A. Lieberman, Michael B. First, Mario Maj, Stamatina VouyioukaAbstract:Tienda online donde Comprar Solid State Polymerization al precio 90,18 € de Allan Tasman | Jerald Kay | Jeffrey A. Lieberman | Michael B. First | Mario Maj | Constantine D. Papaspyrides | Stamatina N. Vouyiouka, tienda de Libros de Medicina, Libros de Psiquiatria - Psiquiatria General
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Polyamide Solid State Polymerization : Evaluation of pertinent kinetic models
Journal of Applied Polymer Science, 2005Co-Authors: Stamatina Vouyiouka, Constantine D. Papaspyrides, J. Weber, D. MarksAbstract:Nylon 6,6 resins, in the form of pellets, were Solid State polymerized in the temperature range of 160–200°C in a fixed-bed reactor under flowing nitrogen for times of 0–4 h. The kinetics of the Solid State Polymerization (SSP) of nylon 6,6 were examined by the evaluation of pertinent rate expressions and the selection of the most suitable one for describing the apparent overall process. The Flory-theory-based kinetic models were the most effective both for this study's data and for data previously published on SSP of different polyamides. Accordingly, SSP rate constants and activation energies were derived, and process parameters, such as the temperature and time, were investigated. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 671–681, 2005
Youdong Shi - One of the best experts on this subject based on the ideXlab platform.
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Reaction Kinetics and Simulations for Solid-State Polymerization of Poly(ethylene terephthalate)
Macromolecules, 1997Co-Authors: Feng Chen, Youdong ShiAbstract:A comprehensive model for Solid-State Polymerization of poly(ethylene terephthalate) was developed from analyzing the similarities and the differences between Solid-State and melt Polymerization. Considering the end groups diffusion limitation and the modification of concentrations of end groups and byproducts in the amorphous phase, a system of mass transfer and balance equations suitable for the Solid-State Polymerization of PET were obtained, based on simplifying the reaction kinetics of melt Polymerization of PET. The degradation and other side reactions neglected in the earlier models for the Solid-State Polymerization of PET were included in the model. This simulation gave a quantitative prediction in the effect of temperature, particle size, starting molecular weight, and ratio of end groups on the degree of Polymerization of products during the Solid-State Polymerization of poly(ethylene terephthalate). These simulation results were in agreement with experiments.
Yoko Tatewaki - One of the best experts on this subject based on the ideXlab platform.
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Solid-State Polymerization of 1,4-bis(hexatriynyl)benzene derivatives
Polymer Journal, 2018Co-Authors: Keita Sasamura, Yoko Tatewaki, Kei Mizuguchi, Shuji OkadaAbstract:Two 1,4-bis(hexatriynyl)benzene derivatives with urethane groups, i.e., 10,10′-(1,4-phenylene)bis(5,7,9-decatriynyl N -(butoxycarbonylmethyl)carbamate) 1 and its perfluorophenylene derivative 2 , were synthesized, and their Solid-State photoPolymerization was investigated. Upon UV irradiation, both of them showed excitonic absorption characteristic of polydiacetylene (PDA). In particular, 2 showed an absorption maximum at 743 nm, which was approximately 100 nm longer than that of conventional PDAs because of the effective conjugation between the polymer backbone and π-conjugated substituents. The conversion of 1 to the corresponding polymer was quite low. On the other hand, more than half of the hexatriynyl moieties of 2 were found to polymerize, indicating that most of the monomers were converted to the polymer upon prolonged UV irradiation. 10,10′-(1,4-Phenylene)bis(5,7,9-decatriynyl N -(butoxycarbonylmethyl)carbamate) 1 and its perfluorophenylene derivative 2 were synthesized. Upon UV irradiation, both of them showed excitonic absorption of polydiacetylene. In particular, 2 showed an absorption maximum at 743 nm, which was approximately 100 nm longer than that of conventional polydiacetylenes, and its Solid-State Polymerization scheme was investigated.
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thermal Solid State Polymerization of a divalent metal salt of an unsaturated carboxylic acid and the effects of additives
Polymer Journal, 2013Co-Authors: Junki Tsuchida, Shuji Okada, Yoko Tatewaki, Satoshi Inayama, Yosuke Saito, Saki Sato, Ushio Yuki, Ayaka Shindo, Chiemi Mikura, Kazuhisa FushiharaAbstract:Thermal Solid-State Polymerization of zinc diacrylate (ZDA) alone and with additives, such as diphenyl disulfide (DPDS) and thiophenol (TP) derivatives and dicumyl peroxide (DCP), was investigated. The Solid-State Polymerization of ZDA was confirmed to be non-topochemical, and the main polymer structure was found to be polyacrylate with acrylate or polyacrylate connected by Zn2+ although a part of the monomer structure was eliminated during the Polymerization. The Polymerization rates were estimated by conversion from ZDA to its polymer, which was determined gravimetrically. The qualitative order of the Polymerization rate was ZDA
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Thermal Solid-State Polymerization of a divalent metal salt of an unsaturated carboxylic acid and the effects of additives
Polymer Journal, 2013Co-Authors: Junki Tsuchida, Shuji Okada, Yoko Tatewaki, Satoshi Inayama, Yosuke Saito, Saki Sato, Ushio Yuki, Ayaka Shindo, Chiemi Mikura, Kazuhisa FushiharaAbstract:Thermal Solid-State Polymerization of zinc diacrylate (ZDA) alone and with additives, such as diphenyl disulfide (DPDS) and thiophenol (TP) derivatives and dicumyl peroxide (DCP), was investigated. The Solid-State Polymerization of ZDA was confirmed to be non-topochemical, and the main polymer structure was found to be polyacrylate with acrylate or polyacrylate connected by Zn^2+ although a part of the monomer structure was eliminated during the Polymerization. The Polymerization rates were estimated by conversion from ZDA to its polymer, which was determined gravimetrically. The qualitative order of the Polymerization rate was ZDA
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Radical-initiator-Induced Solid-State Polymerization of butadiyne nanocrystals in water and their dispersion stabilization.
Journal of Nanoscience and Nanotechnology, 2011Co-Authors: Shuhei Kato, Takahiro Kinemuchi, Akito Masuhara, Shuji Okada, Yoko Tatewaki, Hitoshi Kasai, Hidetoshi OikawaAbstract:: Butadiyne nanocrystals in water are usually polymerized by UV or gamma-ray irradiation to give polydiacetylene (PDA) nanocrystals. In this study, we confirmed that Solid-State Polymerization of 1,6-di(N-carbazolyl)-2,4-hexadiyne (DCHD) and 5,7-dodecadiyn-1,12-diyl bis[N-(butoxycarbonyl-methyl)carbamate] (4BCMU) could be stimulated by water-soluble radical initiators. The radical initiators used were potassium peroxodisulfate, three kinds of azo-type compounds and a redox initiator. In all cases, the Solid-State Polymerization was confirmed by color change into blue indicating that PDA modified by the radical residues at the end was formed. However, nanocrystal cohesion occurred especially when the concentration of the initiators was high or the dispersion was kept for a long time. In order to improve the dispersion stability, two kinds of surfactants, i.e., sodium dodecyl sulfate (SDS) or dodecyltrimethylammonium chloride (DTMAC), were added to the DCHD nanocrystal aqueous dispersion. As a result, when anionic SDS was added, the Solid-State Polymerization of nanocrystals proceeded without coagulation and quantitative conversion was confirmed for all initiators. Cationic DTMAC has no effect on dispersion stabilization. PDA nanocrystal surfaces in water are negatively charged in nature and electric interaction of nanocrystals with the cations results in decrease of surface charge and aggregation of nanocrystals.
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Solid-State Polymerization of conjugated hexayne derivatives with different end groups
Polymer Journal, 2010Co-Authors: Satoshi Inayama, Yoko Tatewaki, Shuji OkadaAbstract:10,12,14,16,18,20-Triacontahexayne-1,30-diol and its diphenylurethane and diphenylester were synthesized, and their Solid-State Polymerization behaviors were investigated. The regular two-step Solid-State Polymerization was confirmed for the diphenylurethane derivative. Three hexayne derivatives with different end groups—that is, 10,12,14,16,18,20-triacontahexayne-1,30-diol ( 1 ) and its diphenylurethane ( 2 ) and diphenylester ( 3 )—were synthesized, and their Solid-State Polymerization behaviors were investigated. All three monomers were thermally polymerizable. Polymers from 1 and 2 showed an absorption maximum at about 730 nm, indicating that linear polydiacetylenes (PDAs) with octatetraynyl substituents were synthesized. However, broad absorption bands in the near-infrared region were only observed for 2 at 980 and 860 nm, indicating that regular Polymerization occurred in 2 to give ladder-type PDA. On the other hand, a polymer from 3 showed a visible absorption increase but no clear absorption maximum. It was estimated that intermolecular hydrogen bonding between hexayne monomers helps to form polymerizable stacks in 1 and 2 . In particular, urethane groups are more effective, and 2 showed the highest reactivity in this study with an ordered interlayer structure even after a two-step Solid-State Polymerization to give ladder-type PDA.