The Experts below are selected from a list of 615 Experts worldwide ranked by ideXlab platform
Alexander Penlidis - One of the best experts on this subject based on the ideXlab platform.
-
making the most of parameter estimation Terpolymerization troubleshooting tips
Processes, 2019Co-Authors: Alison J Scott, Vida A Gabriel, Alexander PenlidisAbstract:Multi-component polymers can provide many advantages over their homopolymer counterparts. Terpolymers are formed from the combination of three unique monomers, thus creating a new material that will exhibit desirable properties based on all three of the original comonomers. To ensure that all three comonomers are incorporated (and to understand and/or predict the degree of incorporation of each comonomer), accurate reactivity ratios are vital. In this study, five Terpolymerization studies from the literature are revisited and the ‘ternary’ reactivity ratios are re-estimated. Some recent studies have shown that binary reactivity ratios (that is, from the related copolymer systems) do not always apply to ternary systems. In other reports, binary reactivity ratios are in good agreement with terpolymer data. This investigation allows for the comparison between previously determined binary reactivity ratios and newly estimated ‘ternary’ reactivity ratios for several systems. In some of the case studies presented herein, reactivity ratio estimation directly from Terpolymerization data is limited by composition restrictions or ill-conditioned systems. In other cases, we observe similar or improved prediction performance (for ternary systems) when ‘ternary’ reactivity ratios are estimated directly from Terpolymerization data (compared to the traditionally used binary reactivity ratios). In order to demonstrate the advantages and challenges associated with ‘ternary’ reactivity ratio estimation, five case studies are presented (with examples and counter-examples) and troubleshooting suggestions are provided to inform future work.
-
The role of pH, ionic strength and monomer concentration on the Terpolymerization of 2-acrylamido-2-methylpropane sulfonic acid, acrylamide and acrylic acid
Polymer, 2019Co-Authors: Alison J Scott, Thomas A. Duever, Alexander PenlidisAbstract:Abstract The current study examines the effects of important factors (namely, pH, ionic strength and monomer concentration) on the Terpolymerization of 2-acrylamido-2-methylpropane sulfonic acid (AMPS), acrylamide (AAm) and acrylic acid (AAc). A good understanding of how these factor levels affect Terpolymerization reactivity ratios, and terpolymer composition, microstructure and molecular weight paves the way for the synthesis of custom-made polymers for specific applications. For the range of conditions studied, ionic strength has the greatest influence on reactivity ratios; results indicate that cross-over behavior exists for AMPS-based reactivity ratios. No clear correlation is observed between pH and reactivity ratio estimates (for 5 ≤ pH ≤ 9), but parameter estimation results suggest that the incorporation of acidic comonomers (AMPS and AAc) is affected by pH within this range. Finally, monomer concentration has a dominant impact on molecular weight averages, even when other factors are varied.
-
Binary vs. ternary reactivity ratios: Appropriate estimation procedures with Terpolymerization data
European Polymer Journal, 2018Co-Authors: Alison J Scott, Alexander PenlidisAbstract:Abstract There is a widely accepted analogy between copolymerization and Terpolymerization mechanisms that has allowed researchers to use reactivity ratios obtained for binary pairs (from copolymerization experiments) in models dealing with Terpolymerizations. However, binary reactivity ratios are not always applicable to Terpolymerization systems; using the binary-ternary analogy (even as an approximation) requires making considerable assumptions about the system. When binary reactivity ratios are used to describe ternary systems, the consequences may include substantial differences in reactivity ratio estimates, poor composition prediction performance, and incorrect determination of product (terpolymer) characteristics. Experimental results and reactivity ratio estimation (via the error-in-variables-model) for the Terpolymerization of 2-acrylamido-2-methylpropane sulfonic acid (AMPS), acrylamide (AAm) and acrylic acid (AAc) (and associated copolymers) are compared, all other conditions being equal.
-
amps aam aac Terpolymerization experimental verification of the evm framework for ternary reactivity ratio estimation
Processes, 2017Co-Authors: Alison J Scott, Niousha Kazemi, Alexander PenlidisAbstract:The complete error-in-variables-model (EVM) framework, consisting of both design of experiments and parameter estimation stages, is applied to the Terpolymerization of 2-acrylamido-2-methylpropane sulfonic acid (AMPS, M1), acrylamide (AAm, M2) and acrylic acid (AAc, M3). This water-soluble terpolymer has potential for applications in enhanced oil recovery, but the associated Terpolymerization kinetic characteristics are largely unstudied. In the current paper, EVM is used to design optimal experiments (for the first time in the literature), and reactivity ratios are subsequently estimated based on both low and medium-high conversion data. The results from the medium-high conversion data are more precise than those from the low conversion data, and are therefore used next to predict the terpolymer composition trajectory over the full course of conversion. Good agreement is seen between experimental data and model predictions, which confirms the accuracy of the newly determined ternary reactivity ratios: r12 = 0.66, r21 = 0.82, r13 = 0.82, r31 = 0.61, r23 = 1.61, r32 = 0.25.
-
AMPS/AAm/AAc Terpolymerization: Experimental Verification of the EVM Framework for Ternary Reactivity Ratio Estimation
MDPI AG, 2017Co-Authors: Alison J Scott, Niousha Kazemi, Alexander PenlidisAbstract:The complete error-in-variables-model (EVM) framework, consisting of both design of experiments and parameter estimation stages, is applied to the Terpolymerization of 2-acrylamido-2-methylpropane sulfonic acid (AMPS, M1), acrylamide (AAm, M2) and acrylic acid (AAc, M3). This water-soluble terpolymer has potential for applications in enhanced oil recovery, but the associated Terpolymerization kinetic characteristics are largely unstudied. In the current paper, EVM is used to design optimal experiments (for the first time in the literature), and reactivity ratios are subsequently estimated based on both low and medium-high conversion data. The results from the medium-high conversion data are more precise than those from the low conversion data, and are therefore used next to predict the terpolymer composition trajectory over the full course of conversion. Good agreement is seen between experimental data and model predictions, which confirms the accuracy of the newly determined ternary reactivity ratios: r12 = 0.66, r21 = 0.82, r13 = 0.82, r31 = 0.61, r23 = 1.61, r32 = 0.25
Alison J Scott - One of the best experts on this subject based on the ideXlab platform.
-
making the most of parameter estimation Terpolymerization troubleshooting tips
Processes, 2019Co-Authors: Alison J Scott, Vida A Gabriel, Alexander PenlidisAbstract:Multi-component polymers can provide many advantages over their homopolymer counterparts. Terpolymers are formed from the combination of three unique monomers, thus creating a new material that will exhibit desirable properties based on all three of the original comonomers. To ensure that all three comonomers are incorporated (and to understand and/or predict the degree of incorporation of each comonomer), accurate reactivity ratios are vital. In this study, five Terpolymerization studies from the literature are revisited and the ‘ternary’ reactivity ratios are re-estimated. Some recent studies have shown that binary reactivity ratios (that is, from the related copolymer systems) do not always apply to ternary systems. In other reports, binary reactivity ratios are in good agreement with terpolymer data. This investigation allows for the comparison between previously determined binary reactivity ratios and newly estimated ‘ternary’ reactivity ratios for several systems. In some of the case studies presented herein, reactivity ratio estimation directly from Terpolymerization data is limited by composition restrictions or ill-conditioned systems. In other cases, we observe similar or improved prediction performance (for ternary systems) when ‘ternary’ reactivity ratios are estimated directly from Terpolymerization data (compared to the traditionally used binary reactivity ratios). In order to demonstrate the advantages and challenges associated with ‘ternary’ reactivity ratio estimation, five case studies are presented (with examples and counter-examples) and troubleshooting suggestions are provided to inform future work.
-
The role of pH, ionic strength and monomer concentration on the Terpolymerization of 2-acrylamido-2-methylpropane sulfonic acid, acrylamide and acrylic acid
Polymer, 2019Co-Authors: Alison J Scott, Thomas A. Duever, Alexander PenlidisAbstract:Abstract The current study examines the effects of important factors (namely, pH, ionic strength and monomer concentration) on the Terpolymerization of 2-acrylamido-2-methylpropane sulfonic acid (AMPS), acrylamide (AAm) and acrylic acid (AAc). A good understanding of how these factor levels affect Terpolymerization reactivity ratios, and terpolymer composition, microstructure and molecular weight paves the way for the synthesis of custom-made polymers for specific applications. For the range of conditions studied, ionic strength has the greatest influence on reactivity ratios; results indicate that cross-over behavior exists for AMPS-based reactivity ratios. No clear correlation is observed between pH and reactivity ratio estimates (for 5 ≤ pH ≤ 9), but parameter estimation results suggest that the incorporation of acidic comonomers (AMPS and AAc) is affected by pH within this range. Finally, monomer concentration has a dominant impact on molecular weight averages, even when other factors are varied.
-
Binary vs. ternary reactivity ratios: Appropriate estimation procedures with Terpolymerization data
European Polymer Journal, 2018Co-Authors: Alison J Scott, Alexander PenlidisAbstract:Abstract There is a widely accepted analogy between copolymerization and Terpolymerization mechanisms that has allowed researchers to use reactivity ratios obtained for binary pairs (from copolymerization experiments) in models dealing with Terpolymerizations. However, binary reactivity ratios are not always applicable to Terpolymerization systems; using the binary-ternary analogy (even as an approximation) requires making considerable assumptions about the system. When binary reactivity ratios are used to describe ternary systems, the consequences may include substantial differences in reactivity ratio estimates, poor composition prediction performance, and incorrect determination of product (terpolymer) characteristics. Experimental results and reactivity ratio estimation (via the error-in-variables-model) for the Terpolymerization of 2-acrylamido-2-methylpropane sulfonic acid (AMPS), acrylamide (AAm) and acrylic acid (AAc) (and associated copolymers) are compared, all other conditions being equal.
-
amps aam aac Terpolymerization experimental verification of the evm framework for ternary reactivity ratio estimation
Processes, 2017Co-Authors: Alison J Scott, Niousha Kazemi, Alexander PenlidisAbstract:The complete error-in-variables-model (EVM) framework, consisting of both design of experiments and parameter estimation stages, is applied to the Terpolymerization of 2-acrylamido-2-methylpropane sulfonic acid (AMPS, M1), acrylamide (AAm, M2) and acrylic acid (AAc, M3). This water-soluble terpolymer has potential for applications in enhanced oil recovery, but the associated Terpolymerization kinetic characteristics are largely unstudied. In the current paper, EVM is used to design optimal experiments (for the first time in the literature), and reactivity ratios are subsequently estimated based on both low and medium-high conversion data. The results from the medium-high conversion data are more precise than those from the low conversion data, and are therefore used next to predict the terpolymer composition trajectory over the full course of conversion. Good agreement is seen between experimental data and model predictions, which confirms the accuracy of the newly determined ternary reactivity ratios: r12 = 0.66, r21 = 0.82, r13 = 0.82, r31 = 0.61, r23 = 1.61, r32 = 0.25.
-
AMPS/AAm/AAc Terpolymerization: Experimental Verification of the EVM Framework for Ternary Reactivity Ratio Estimation
MDPI AG, 2017Co-Authors: Alison J Scott, Niousha Kazemi, Alexander PenlidisAbstract:The complete error-in-variables-model (EVM) framework, consisting of both design of experiments and parameter estimation stages, is applied to the Terpolymerization of 2-acrylamido-2-methylpropane sulfonic acid (AMPS, M1), acrylamide (AAm, M2) and acrylic acid (AAc, M3). This water-soluble terpolymer has potential for applications in enhanced oil recovery, but the associated Terpolymerization kinetic characteristics are largely unstudied. In the current paper, EVM is used to design optimal experiments (for the first time in the literature), and reactivity ratios are subsequently estimated based on both low and medium-high conversion data. The results from the medium-high conversion data are more precise than those from the low conversion data, and are therefore used next to predict the terpolymer composition trajectory over the full course of conversion. Good agreement is seen between experimental data and model predictions, which confirms the accuracy of the newly determined ternary reactivity ratios: r12 = 0.66, r21 = 0.82, r13 = 0.82, r31 = 0.61, r23 = 1.61, r32 = 0.25
Zhiqiang Fan - One of the best experts on this subject based on the ideXlab platform.
-
ethylene propylene copolymerization and their Terpolymerization with dienes using ansa zirconocene catalysts activated by borate alkylaluminum
Journal of Macromolecular Science Part A, 2020Co-Authors: Amjad Ali, Muhammad Adnan Akram, Yintian Guo, Wucan Liu, Akbar Khan, Xiaoyu Liu, Zhiqiang FanAbstract:Copolymerization of ethylene (E) and propylene (P) and their Terpolymerizations with three kinds of diene (5-ethylidene-2-norbornene (ENB), 4-vinylcyclohexene (VCH) and 1,4-hexadiene (HD)) under 4 ...
-
well defined high refractive index poly monothiocarbonate with tunable abbe s numbers and glass transition temperatures via Terpolymerization
Polymer Chemistry, 2015Co-Authors: Ming Luo, Xinghong Zhang, Qi Wang, Zhiqiang FanAbstract:The synthesis of thermoplastics with high refractive index (n) and high Abbe's number (Vd) is rarely reported. This work describes well-controlled synthesis of a soluble poly(monothiocarbonate) with high n and Vd values by using carbonyl sulfide (COS) as a source of sulfur. The alternating COS/cyclohexene oxide (CHO)/propylene oxide (PO) Terpolymerization was performed by using a tetradentate Schiff base chromium chloride complex (SalenCrCl) and bis(triphenylphosphoranylidene) ammonium chloride (PPNCl) as a catalyst at 40 °C, yielding terpolymers with 100% poly(monothiocarbonate) selectivity based on the 1H NMR spectra. The turnover frequency (TOF) of the SalenCrCl/PPNCl catalyst system was 323 h−1 for COS/PO/CHO Terpolymerization at 40 °C. The terpolymers possess number-average molecular weight (Mn) up to 22.3 kg mol−1 with a narrow polydispersity index (PDI) of 1.16. These terpolymers exhibited high refractive indices (n) of 1.55–1.56. Of importance, by varying the feed ratio of PO and CHO, Vd of the resulting terpolymers was adjustable from 32.1 to 43.1, and the glass-transition temperature (Tg) varied from 43.7 to 93.4 °C. This poly(monothiocarbonate) might be used as optical plastics with tailored optical and thermal properties.
-
one pot Terpolymerization of co2 cyclohexene oxide and maleic anhydride using a highly active heterogeneous double metal cyanide complex catalyst
Polymer, 2010Co-Authors: Xueke Sun, Xinghong Zhang, Shang Chen, Qi Wang, Zhiqiang FanAbstract:Abstract This paper describes a convenient one-pot Terpolymerization of CO2, cyclohexene oxide (CHO) and maleic anhydride (MAH) to afford a poly (ester-carbonate) with a low content of ether units (2.9–4.3 mol%) using a highly active Zn–Co(III) double metal cyanide complex (DMCC) catalyst. Terpolymerization was carried out in tetrahydrofuran (THF) at 75–90 °C and 1.0–4.0 MPa and no cyclic carbonate was observed in NMR spectra. The number-average molecular weight (Mn) of the terpolymer was up to 14.1 kg/mol with a narrow molecular weight distribution of 1.4–1.7. The apparent efficiency of the catalyst was up to 12.7 kg polymer/g Zn, representing the highest catalytic activity for Terpolymerization of CO2, epoxides and cyclic anhydrides to date. THF dramatically inhibited polyether formation in this Terpolymerization owing to its nucleophilicity towards the Zn2+ center of Zn–Co (III) DMCC. This presents the first example of solvent-assisted selectivity for inhibiting ether units in CO2 polymerization catalyzed by a heterogeneous system. Kinetic analyses of MAH/CHO/CO2 Terpolymerization (MAH/CHO 0.2) suggested that polyester production was slightly faster than polycarbonate production in the early stage. A mechanism for this Terpolymerization catalyzed by Zn–Co (III) DMCC catalyst was proposed. Moreover, addition of small amounts of MAH (MAH/CHO molar ratio ≤0.2) during CO2/CHO copolymerization can improve the thermal properties of the resultant terpolymers.
Bun Yeoul Lee - One of the best experts on this subject based on the ideXlab platform.
-
copolymerization and Terpolymerization of carbon dioxide propylene oxide phthalic anhydride using a salen co iii complex tethering four quaternary ammonium salts
Beilstein Journal of Organic Chemistry, 2014Co-Authors: Jong Yeob Jeon, Jobi Kodiyan Varghese, Bun Yeoul LeeAbstract:The (salen)Co(III) complex 1 tethering four quaternary ammonium salts, which is a highly active catalyst in CO2/epoxide copolymerizations, shows high activity for propylene oxide/phthalic anhydride (PO/PA) copolymerizations and PO/CO2/PA Terpolymerizations. In the PO/PA copolymerizations, full conversion of PA was achieved within 5 h, and strictly alternating copolymers of poly(1,2-propylene phthalate)s were afforded without any formation of ether linkages. In the PO/CO2/PA Terpolymerizations, full conversion of PA was also achieved within 4 h. The resulting polymers were gradient poly(1,2-propylene carbonate-co-phthalate)s because of the drift in the PA concentration during the Terpolymerization. Both polymerizations showed immortal polymerization character; therefore, the molecular weights were determined by the activity (g/mol-1) and the number of chain-growing sites per 1 [anions in 1 (5) + water (present as impurity) + ethanol (deliberately fed)], and the molecular weight distributions were narrow (Mw/Mn, 1.05–1.5). Because of the extremely high activity of 1, high-molecular-weight polymers were generated (Mn up to 170,000 and 350,000 for the PO/PA copolymerization and PO/CO2/PA Terpolymerization, respectively). The terpolymers bearing a substantial number of PA units (fPA, 0.23) showed a higher glass-transition temperature (48 °C) than the CO2/PO alternating copolymer (40 °C).
-
Copolymerization and Terpolymerization of carbon dioxide/propylene oxide/phthalic anhydride using a (salen)Co(III) complex tethering four quaternary ammonium salts
Beilstein-Institut, 2014Co-Authors: Jong Yeob Jeon, Jobi Kodiyan Varghese, Bun Yeoul LeeAbstract:The (salen)Co(III) complex 1 tethering four quaternary ammonium salts, which is a highly active catalyst in CO2/epoxide copolymerizations, shows high activity for propylene oxide/phthalic anhydride (PO/PA) copolymerizations and PO/CO2/PA Terpolymerizations. In the PO/PA copolymerizations, full conversion of PA was achieved within 5 h, and strictly alternating copolymers of poly(1,2-propylene phthalate)s were afforded without any formation of ether linkages. In the PO/CO2/PA Terpolymerizations, full conversion of PA was also achieved within 4 h. The resulting polymers were gradient poly(1,2-propylene carbonate-co-phthalate)s because of the drift in the PA concentration during the Terpolymerization. Both polymerizations showed immortal polymerization character; therefore, the molecular weights were determined by the activity (g/mol-1) and the number of chain-growing sites per 1 [anions in 1 (5) + water (present as impurity) + ethanol (deliberately fed)], and the molecular weight distributions were narrow (Mw/Mn, 1.05–1.5). Because of the extremely high activity of 1, high-molecular-weight polymers were generated (Mn up to 170,000 and 350,000 for the PO/PA copolymerization and PO/CO2/PA Terpolymerization, respectively). The terpolymers bearing a substantial number of PA units (fPA, 0.23) showed a higher glass-transition temperature (48 °C) than the CO2/PO alternating copolymer (40 °C)
Srinivas Darbha - One of the best experts on this subject based on the ideXlab platform.
-
structure induced catalytic activity of co zn double metal cyanide complexes for Terpolymerization of propylene oxide cyclohexene oxide and co2
RSC Advances, 2015Co-Authors: Joby Sebastian, Srinivas DarbhaAbstract:The application of Co–Zn double-metal cyanide (DMC) complexes as catalysts for selective Terpolymerization of propylene oxide, cyclohexene oxide and CO2 producing polycarbonates is reported for the first time. DMC complexes were prepared with and without using a co-complexing agent. The catalyst with monoclinic/rhombohedral crystal structure and strong Lewis acidity, prepared without using a co-complexing agent showed higher initial activity than that with a cubic structure prepared using a co-complexing agent. Interestingly, no induction period in the Terpolymerization reaction was observed. The terpolymer has 75.5 mol% of carbonate fraction in its composition and an average molecular weight of 22 700 and polydispersity index of 2.97. It is characterized by a Tg of 55 °C. This structure-induced catalytic activity of DMC can open up new avenues for its applications in other reactions. The influence of process parameters on the catalytic activity of DMC was investigated.
