Kinetic Features of Isophorone Diisocyanate and Oligoesterdiols Reaction under Waterborne Polyurethane Synthesis Conditions and the Preparation of the Polymer Dispersions

2020 ◽  
Vol 869 ◽  
pp. 508-515
Author(s):  
Sergei V. Karpov ◽  
Aygul S. Dzhalmukhanova ◽  
Dmitry A. Chernyayev ◽  
Vera P. Lodygina ◽  
Victoria V. Komratova ◽  
...  
Keyword(s):  
Waterborne Polyurethane ◽  
Catalytic Reactions ◽  
Dibutyltin Dilaurate ◽  
Isophorone Diisocyanate ◽  
Synthesis Conditions ◽  
Waterborne Polyurethanes ◽  
Order Of Magnitude ◽  
Polymer Dispersions ◽  
Kinetics Of ◽  
Kinetic Features

Kinetics of urethane formation from isophorone diisocyanate and polycaprolactone diol and poly(butylene adipate) in acetone was studied by IR spectroscopy. It was found that poly(butylene adipate) is the most reactive oligoesterdiol, with the reaction being both non-catalyzed and catalyzed by dibutyltin dilaurate. It was shown that the cycloaliphatic group of isophorone diisocyanate is an order of magnitude more active than the aliphatic one in catalytic reactions of isophorone diisocyanate with investigated oligoesterdiols. Furthermore, waterborne polyurethanes based on the studied oligoesterdiols were synthesized and characterized by DLS, DSC, and TGA methods.

Preparation and Application of Undecylenate Based Diol for Bio-Based Waterborne Polyurethane Dispersion

2014 ◽  
Vol 955-959 ◽  
pp. 88-91 ◽  
Author(s):  
Zhe Yang ◽  
Yan Bin Zhu ◽  
Fang Peng ◽  
Chang Qing Fu
Keyword(s):  
Castor Oil ◽  
Room Temperature ◽  
Click Reaction ◽  
Waterborne Polyurethane ◽  
Chain Extender ◽  
Proton Nuclear Magnetic Resonance ◽  
Isophorone Diisocyanate ◽  
Polyurethane Dispersion ◽  
Waterborne Polyurethanes ◽  
Ft Ir

The undecylenate based diol (UAD) has been synthesized from undecylenate by esterification and thiol-ene click reaction sequently, and then it was used as a diol to prepare bio-based waterborne polyurethane (WPU) reacting with isophorone diisocyanate (IPDI) and castor oil-based carboxyl hydrophilic chain extender. The structure of undecylenate based diol was verified by hydrogen proton nuclear magnetic resonance (1H NMR). Fourier transform infrared spectroscopy (FT-IR) was used to characterize the structure of WPU film. Furthermore, particle size and viscosity were used to character apparent properties of the bio-based waterborne polyurethane dispersion. The result shows that: bio-based waterborne polyurethane dispersion is transparent and very stable under room temperature. This work provides a simple and efficient method for the preparation of fatty acids based polyols and bio-based waterborne polyurethanes.

scholarly journals Synthesis of Waterborne Polyurethane Using Phosphorus-Modified Rigid Polyol and its Physical Properties

Polymers ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 432
Author(s):  
Taewoo Jang ◽  
Hye Jin Kim ◽  
Jeong Beom Jang ◽  
Tae Hee Kim ◽  
Wonjoo Lee ◽  
...  
Keyword(s):  
Physical Properties ◽  
Reference Sample ◽  
Waterborne Polyurethane ◽  
Decomposition Temperature ◽  
Molar Ratio ◽  
Isophorone Diisocyanate ◽  
Produce Water ◽  
Molar Ratios ◽  
Waterborne Polyurethanes ◽  
Excess Amount

In this study, a phosphorous-containing polyol (P-polyol) was synthesized and reacted with isophorone diisocyanate (IPDI) to produce water-dispersed polyurethane. To synthesize waterborne polyurethanes (WPUs), mixtures of P-polyol and polycarbonate diol (PCD) were reacted with IPDI, followed by the addition of dimethylol propionic acid, to confer hydrophilicity to the produced polyurethane. An excess amount of water was used to disperse polyurethane in water, and the terminal isocyanate groups of the resulting WPUs were capped with ethylene diamine. P-polyol:PCD molar ratios of 0.1:0.9, 0.2:0.8, and 0.3:0.7 were used to synthesize WPUs. The films prepared by casting and drying the synthesized WPUs in plastic Petri dishes were used to test the changes in physical properties induced by changing the P-polyol:PCD molar ratio. The experimental results revealed that the tensile strength of PU-10, the WPU with a P-polyol:PCD molar ratio of 0.1:0.9, was 16% higher than that of the reference P-polyol–free WPU sample. Moreover, the thermal decomposition temperature of PU-10 was 27 °C higher than that of the reference sample.

Kinetics of oxidation of ammonia on cobalt catalyst I model of the reactor with catalytically active wall

1982 ◽  
Vol 47 (8) ◽  
pp. 2087-2096 ◽  
Author(s):  
Bohumil Bernauer ◽  
Antonín Šimeček ◽  
Jan Vosolsobě
Keyword(s):  
Parabolic Equations ◽  
Cobalt Catalyst ◽  
Nonlinear Parabolic Equations ◽  
Catalytic Reactions ◽  
Temperature Profiles ◽  
Dimensional Model ◽  
Kinetics Of Oxidation ◽  
Nonlinear Parabolic ◽  
Catalytically Active ◽  
Kinetics Of

A two dimensional model of a tabular reactor with the catalytically active wall has been proposed in which several exothermic catalytic reactions take place. The derived dimensionless equations enable evaluation of concentration and temperature profiles on the surface of the active component. The resulting nonlinear parabolic equations have been solved by the method of orthogonal collocations.

scholarly journals Reduction Mechanism of Fine Hematite Ore Particles in Suspension

2021 ◽  
Author(s):  
Zhiyuan Chen ◽  
Christiaan Zeilstra ◽  
Jan van der Stel ◽  
Jilt Sietsma ◽  
Yongxiang Yang
Keyword(s):  
Particle Size ◽  
Temperature Drop ◽  
Reduction Rate ◽  
Reduction Process ◽  
Reciprocal Relationship ◽  
Drop Tube ◽  
Surface Nucleation ◽  
Order Of Magnitude ◽  
Relationship Of ◽  
Kinetics Of

AbstractIn order to understand the pre-reduction behaviour of fine hematite particles in the HIsarna process, change of morphology, phase and crystallography during the reduction were investigated in the high temperature drop tube furnace. Polycrystalline magnetite shell formed within 200 ms during the reduction. The grain size of the magnetite is in the order of magnitude of 10 µm. Lath magnetite was observed in the partly reduced samples. The grain boundary of magnetite was reduced to molten FeO firstly, and then the particle turned to be a droplet. The Johnson-Mehl-Avrami-Kolmogorov model is proposed to describe the kinetics of the reduction process. Both bulk and surface nucleation occurred during the reduction, which leads to the effect of size on the reduction rate in the nucleation and growth process. As a result, the reduction rate constant of hematite particles increases with the increasing particle size until 85 µm. It then decreases with a reciprocal relationship of the particle size above 85 µm.

scholarly journals Ice Coverage Induced by Depositing a Water Drop onto the Supercooled Substrate at Extreme Low Vapor Pressure

Crystals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 691
Author(s):  
Yugang Zhao ◽  
Zichao Zuo ◽  
Haibo Tang ◽  
Xin Zhang
Keyword(s):  
Vapor Pressure ◽  
Substrate Temperature ◽  
Water Drop ◽  
Industrial Processes ◽  
Aircraft Icing ◽  
Ice Coverage ◽  
Fundamental Understanding ◽  
Order Of Magnitude ◽  
The Impact ◽  
Kinetics Of

Icing/snowing/frosting is ubiquitous in nature and industrial processes, and the accretion of ice mostly leads to catastrophic consequences. The existing understanding of icing is still limited, particularly for aircraft icing, where direct observation of the freezing dynamics is inaccessible. In this work, we investigate experimentally the impact and freezing of a water drop onto the supercooled substrate at extremely low vapor pressure, to mimic an aircraft passing through clouds at a relatively high altitude, engendering icing upon collisions with pendant drops. Special attention is focused on the ice coverage induced by an impinging drop, from the perimeter pointing outward along the radial direction. We observed two freezing regimes: (I) spread-recoil-freeze at the substrate temperature of Ts = −15.4 ± 0.2 °C and (II) spread (incomplete)-freeze at the substrate temperature of Ts = −22.1 ± 0.2 °C. The ice coverage is approximately one order of magnitude larger than the frozen drop itself, and counterintuitively, larger supercooling yields smaller ice coverage in the range of interest. We attribute the variation of ice coverage to the kinetics of vapor diffusion in the two regimes. This fundamental understanding benefits the design of new anti-icing technologies for aircraft.

through tubing and fittings made of PTFE. Analysis was undertaken by the Warren Spring Laboratory of the Department of Trade and Industry, according to the method described by Bailey and Bedbo rough The results are shown in Table IV. and plotted in Fig. 3. and 4. Table IV. Variation of odour strength of extracted samples with volune of eluted air Volume of air Strength of odour samples passing through (dilutions) sludge before sampling (1/1) Raw sludge Digested sludge 0 154 000 9 900 11.1 53 000 350 22.2 30 600 270 55.6 15 500 190 111 8 200 160 It is clear from these results that there is considerable die-off of odour strength with time, and that, as would be expected, the anaerobic digestion of sludge can reduce the odour potential by at least one order of magnitude. To illustrate the importance of this die-off effect, the results have been re-plotted in Fig. 5. in a cunulative form; that is to say as cumulative percentage of the eventual colour release against volume of air. In the case of the raw sewage sludge, 38% of the ultimate odour was carried in the first odour sample, and 90% of the odour had been extracted by the passage of about 200 1. In the case of the anaerobically digested sludge, the same effect is much more marked; 72% of the ultimate odour was carried by the first sample, and thereafter the strength of the odour fell off very rapidly. There are two possible explanations for this. First, it can be postulated that as it is known that many of the important odorous chemical species are highly volatile, they may be only physically trapped in the sludge, and need little encouragement to transfer to the atmosphere. An alternative explanation concerns the existence of two equilibria. As the vapour/liquid equilibrium is disturbed by the passage of air, the concentration of dissolved compounds in the liquid phase falls, disturbing the ’solid’/liquid equilibrium The kinetics of transfer across this latter phase boundary are much slower than for the liquid/vapour transfer, so that the extraction of odour becomes limited by the rate of diffusion into the liquid phase. Two observations may be cited as evidence for this latter view. First, when sludge is applied to land, there is a rapid tail-off of odour nuisance after spreading. Hie incidence of rain after a dry period is known to result in an increased evolution of odour. Second, in earlier experiments samples of sludge were centrifuged, and the supernatant liquor discarded and replaced by tap water, before being used in the standard odour potential test. Some re-extraction of odour from the samples was rapidly found. In practice, both postulated mechanisms are probably at work, especially if the concept of ’solid/liquid equilibrium’ be extended to

1986 ◽  
pp. 152-152
Keyword(s):  
Liquid Phase ◽  
Tap Water ◽  
Chemical Species ◽  
Liquid Equilibrium ◽  
Digested Sludge ◽  
Order Of Magnitude ◽  
Anaerobically Digested Sludge ◽  
Solid Liquid ◽  
Kinetics Of ◽  
Potential Test
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