The Experts below are selected from a list of 4140 Experts worldwide ranked by ideXlab platform
Janusz Datta - One of the best experts on this subject based on the ideXlab platform.
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novel bio based thermoplastic poly ether urethane s correlations between the structure processing and properties
Polymer, 2019Co-Authors: Paulina Kasprzyk, Janusz DattaAbstract:Abstract The main purpose of this work was to analyze the effect of the number of unreacted isocyanate groups and the [NCO]/[OH] molar ratio during the chain extension of a Prepolymer during the polymerization process on the structure, processing and selected properties of thermoplastic poly(ether-urethane)s. Three series of novel thermoplastic polyurethanes were obtained via a Prepolymer route. Three Prepolymers were synthesized from diisocyanate and bio-based polyol, which contained 6, 7 and 8% of unreacted isocyanate groups. The Prepolymer chains were extended by using bio-based 1,4-butanediol with four different [NCO]/[OH] molar ratios. It was confirmed that the concentration of unreacted isocyanate groups in the Prepolymer has an effect on the degree of the hard segment phase separation of poly(ether-urethane)s. It was also found that the melt flow index has a significant impact on the processing of polyurethanes which can be correlated to the chemical structure and dynamic mechanical properties of the polyurethanes.
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effect of hydroxylated soybean oil and bio based propanediol on the structure and thermal properties of synthesized bio polyurethanes
Industrial Crops and Products, 2014Co-Authors: Janusz Datta, Ewa GlowinskaAbstract:The aim of this work was to obtain bio-polyurethanes using synthetic compounds and bio-components, i.e. bio-glycols. Bio-polyurethanes were prepared by means of the Prepolymer method. Prepolymers were synthesized from 4,4′-diphenylmethane diisocyanate (MDI) and a polyol mixture containing 75% by weight of commercial polyether and 25% by weight of hydroxylated soybean oils (H2 or H3), the latter being obtained in the reaction with bio-glycol during the hydroxylation process. Bio-components were also used as chain extenders of Prepolymer, i.e. bio-based 1,2- or bio-based 1,3-propanediol (1,2bioPDO or 1,3bioPDO). The reaction was catalyzed by 1,4-diazabicyclo[2.2.2]octane (DABCO). The influence of the content of low molecular chain extenders on the structure and thermomechanical properties of the obtained bio-polyurethanes was investigated. The FTIR analysis demonstrated that different types of bio-propanediol change the chemical structure of the obtained bio-polyether urethanes. The results of thermomechanical analysis showed that the application of 1,2-bio-propanediol as a chain extender was advantageous in comparison to bio-based 1,3-propanediol; the polyurethanes produced with 1,2-bio-propanediol exhibited higher storage modulus and lower loss modulus.
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a mathematical model of rheological behavior of novel bio based isocyanate terminated polyurethane Prepolymers
Industrial Crops and Products, 2014Co-Authors: Ewa Glowinska, Janusz DattaAbstract:In this paper, the results of rheological study on isocyanate-terminated polyurethane Prepolymers, containing modified soybean oil residues incorporated into the chemical structure are described. Isocyanate-terminated Prepolymers were synthesized from 4,4′-diphenylmethane diisocyanate and the mixture of hydroxylated soybean oil and commercial polyether. The measurements were performed by using rotary rheometer R/S-CPS+ (Brookfield, USA), while the rheological parameters were calculated by using Rheo3000 program. Based on rheological measurements, the viscosity curves and flow curves for Prepolymers in the temperature range from 50 to 70 °C were plotted. Prepolymer samples were tested with controlled shear rate (CSR). It was found that a viscosity of bio-based isocyanate-terminated Prepolymers decreases with increasing content of hydroxylated soybean oil in the polyol mixture. The rheological data for bio-based polyurethane Prepolymers were also mathematically modeled. It was found that the synthesized Prepolymers are non-Newtonian fluids that can be described by Ostwald-de Waele and Herschel Bulkley functions as optimal individual models. The conducted investigations showed that the dynamic viscosity and rheological behavior of bioPrepolymers samples could depend on the amount of hydroxylated soybean oil used in the polyol mixture.
Mohamed Taha - One of the best experts on this subject based on the ideXlab platform.
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diels alder thermoresponsive networks based on high maleimide functionalized urethane Prepolymers
Designed Monomers and Polymers, 2013Co-Authors: Nidhal Okhay, Nathalie Mignard, Corinne Jegat, Mohamed TahaAbstract:Thermoreversible polyurethane networks were successfully prepared by Diels–Alder reaction using a highly maleimide-functionalized urethane Prepolymer with an epoxy-based furan coupling agent or a furan-functionalized polyurethane. Highly functional maleimide Prepolymers with various functionalities were synthesized by the isocyanate-alcohol reaction from glycerol, H12MDI, and protected N-hydroxymethylmaleimide. Thermal behavior and de-crosslinking of the networks were studied via thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and solubility tests. Swelling tests allowed the evaluation of the networks’ density. Thermal properties and crosslinking density were influenced by furan and maleimide functionalities and by the nature of the diene. Denser networks with lower de-crosslinking temperatures were obtained using the epoxy-based furan coupling agent. With the furan-functionalized polyurethanes, looser networks and higher de-crosslinking temperatures were obtained. These higher ...
Ewa Glowinska - One of the best experts on this subject based on the ideXlab platform.
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effect of hydroxylated soybean oil and bio based propanediol on the structure and thermal properties of synthesized bio polyurethanes
Industrial Crops and Products, 2014Co-Authors: Janusz Datta, Ewa GlowinskaAbstract:The aim of this work was to obtain bio-polyurethanes using synthetic compounds and bio-components, i.e. bio-glycols. Bio-polyurethanes were prepared by means of the Prepolymer method. Prepolymers were synthesized from 4,4′-diphenylmethane diisocyanate (MDI) and a polyol mixture containing 75% by weight of commercial polyether and 25% by weight of hydroxylated soybean oils (H2 or H3), the latter being obtained in the reaction with bio-glycol during the hydroxylation process. Bio-components were also used as chain extenders of Prepolymer, i.e. bio-based 1,2- or bio-based 1,3-propanediol (1,2bioPDO or 1,3bioPDO). The reaction was catalyzed by 1,4-diazabicyclo[2.2.2]octane (DABCO). The influence of the content of low molecular chain extenders on the structure and thermomechanical properties of the obtained bio-polyurethanes was investigated. The FTIR analysis demonstrated that different types of bio-propanediol change the chemical structure of the obtained bio-polyether urethanes. The results of thermomechanical analysis showed that the application of 1,2-bio-propanediol as a chain extender was advantageous in comparison to bio-based 1,3-propanediol; the polyurethanes produced with 1,2-bio-propanediol exhibited higher storage modulus and lower loss modulus.
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a mathematical model of rheological behavior of novel bio based isocyanate terminated polyurethane Prepolymers
Industrial Crops and Products, 2014Co-Authors: Ewa Glowinska, Janusz DattaAbstract:In this paper, the results of rheological study on isocyanate-terminated polyurethane Prepolymers, containing modified soybean oil residues incorporated into the chemical structure are described. Isocyanate-terminated Prepolymers were synthesized from 4,4′-diphenylmethane diisocyanate and the mixture of hydroxylated soybean oil and commercial polyether. The measurements were performed by using rotary rheometer R/S-CPS+ (Brookfield, USA), while the rheological parameters were calculated by using Rheo3000 program. Based on rheological measurements, the viscosity curves and flow curves for Prepolymers in the temperature range from 50 to 70 °C were plotted. Prepolymer samples were tested with controlled shear rate (CSR). It was found that a viscosity of bio-based isocyanate-terminated Prepolymers decreases with increasing content of hydroxylated soybean oil in the polyol mixture. The rheological data for bio-based polyurethane Prepolymers were also mathematically modeled. It was found that the synthesized Prepolymers are non-Newtonian fluids that can be described by Ostwald-de Waele and Herschel Bulkley functions as optimal individual models. The conducted investigations showed that the dynamic viscosity and rheological behavior of bioPrepolymers samples could depend on the amount of hydroxylated soybean oil used in the polyol mixture.
Nidhal Okhay - One of the best experts on this subject based on the ideXlab platform.
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diels alder thermoresponsive networks based on high maleimide functionalized urethane Prepolymers
Designed Monomers and Polymers, 2013Co-Authors: Nidhal Okhay, Nathalie Mignard, Corinne Jegat, Mohamed TahaAbstract:Thermoreversible polyurethane networks were successfully prepared by Diels–Alder reaction using a highly maleimide-functionalized urethane Prepolymer with an epoxy-based furan coupling agent or a furan-functionalized polyurethane. Highly functional maleimide Prepolymers with various functionalities were synthesized by the isocyanate-alcohol reaction from glycerol, H12MDI, and protected N-hydroxymethylmaleimide. Thermal behavior and de-crosslinking of the networks were studied via thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and solubility tests. Swelling tests allowed the evaluation of the networks’ density. Thermal properties and crosslinking density were influenced by furan and maleimide functionalities and by the nature of the diene. Denser networks with lower de-crosslinking temperatures were obtained using the epoxy-based furan coupling agent. With the furan-functionalized polyurethanes, looser networks and higher de-crosslinking temperatures were obtained. These higher ...
Jannick Duchet-rumeau - One of the best experts on this subject based on the ideXlab platform.
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Development of Sustainable Thermosets from Cardanol-based Epoxy Prepolymer and Ionic Liquids
ACS Sustainable Chemistry & Engineering, 2017Co-Authors: Thi Khanh Ly Nguyen, Sebastien Livi, Jean-françois Gérard, Bluma G. Soares, Guilherme M.o. Barra, Jannick Duchet-rumeauAbstract:In this work, the development of new biobased epoxy networks using phosphonium-based ionic liquids combined with dicyanamide and phosphinate counteranions as initiators of epoxy Prepolymers was compared with a biobased epoxy–amine system. Ionic liquids (ILs) displayed high reactivity toward cardanol-based epoxy Prepolymers, and the obtained biobased epoxy/IL networks highlighted a glass transition temperature of around 30 °C, an excellent thermal stability higher than 450 °C and higher hydrophobic behavior compared to biobased epoxy–amine networks. In addition, the use of a cardanol-based epoxy Prepolymer as a modifier of epoxy/IL networks was also investigated. In this case, the final properties of epoxy/IL networks were improved by the presence of biobased epoxy compounds, especially their surface energy as well as their fracture toughness (+180%), suggesting a new way to develop partially biobased epoxy coatings.
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Development of Sustainable Thermosets from Cardanol-based Epoxy Prepolymer and Ionic Liquids
2017Co-Authors: Thi Khanh Ly Nguyen, Bluma G. Soares, Guilherme M.o. Barra, Sébastien Livi, Jean-françois Gérard, Jannick Duchet-rumeauAbstract:In this work, the development of new biobased epoxy networks using phosphonium-based ionic liquids combined with dicyanamide and phosphinate counteranions as initiators of epoxy Prepolymers was compared with a biobased epoxy–amine system. Ionic liquids (ILs) displayed high reactivity toward cardanol-based epoxy Prepolymers, and the obtained biobased epoxy/IL networks highlighted a glass transition temperature of around 30 °C, an excellent thermal stability higher than 450 °C and higher hydrophobic behavior compared to biobased epoxy–amine networks. In addition, the use of a cardanol-based epoxy Prepolymer as a modifier of epoxy/IL networks was also investigated. In this case, the final properties of epoxy/IL networks were improved by the presence of biobased epoxy compounds, especially their surface energy as well as their fracture toughness (+180%), suggesting a new way to develop partially biobased epoxy coatings
