Reaction Of Toluene Diisocyanate Research Articles

Synthesis and characterization of isocyanic bonding agents by the reaction of TDI and 5,5‐dimethylhydantoin for use in composite propellants

AbstractThis paper aims to present the study of obtaining a potential isocyanic bonding agent. The process is based on introducing free isocyanate groups into hydantoin ring. In addition to acting as bonding agents, they can act as curing agents, promoting the formation of cross‐links with the binder so that the propellant cures. The synthesis process consisted of the reaction between toluene diisocyanate (TDI) and 5,5‐dimethylhydantoin (DMH) under different parameters (time, temperature, reaction atmosphere, solvent, and product purification). The reactions were monitored by Fourier transform infrared spectroscopy in the mid‐infrared region (FT‐IR). Furthermore, the product obtained was characterized by thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), elemental analysis (CHN), and volumetric chemistry (determination of the isocyanate‐NCO index). Changes in physical characteristics and the results of the determination of index NCO, FT‐IR, TGA, DSC, and CHN analysis indicate that the proposed reactions occurred. It is concluded that, among the parameters studied, those most suitable for the reaction system between isocyanic reagents TDI and DMH are a temperature of 90 °C, coupling of a nitrogen cylinder, and use of toluene solvent in the reaction system.

Benign fabrication process of hierarchal porous polyurea microspheres with tunable pores and porosity: Their Pd immobilization and use for hexavalent chromium reduction

Developing new strategies for fabrication of porous materials with tunable morphology which have fewer environmental impacts is highly desired. Herein, conventional precipitation polymerization of polyurea (PU) synthesis is converted to interfacial polymerization via simple microfluidics and hierarchically porous and uniform PU microspheres (PPM) are prepared by the reaction of toluene diisocyanate and water, eliminating the use of toxic amines and organic solvents. The morphology and porosity of PPM are probed. The size of PPM is controlled by changing the diameter of flow channels of microfluidic device and their pore size and porosity are tuned by optimizing the polymerization conditions. Moreover, palladium (Pd) is immobilized on PPM by impregnation and subsequent reduction approach to get Pd@PPM. The hybrid composite, Pd@PPM, is used for catalytic reduction of toxic Cr6+ to benign Cr3+ by formic acid as a reductant along with sodium format as a promoter in aqueous system. Pd@PPM exhibited high catalytic activity and good stability for Cr6+ reduction and their large size with high uniformity eased their recovery to reuse them in subsequent Cr6+ reduction. Porous PU with controllable shape and morphology are rarely available. This work therefore provides new strategy to synthesis PPM with controllable porous morphology and their use as an effective support for catalysis.

Preparation, Characterization of Palm Oil Based Polyols Reinforced with Bentonite-Chitosan as A Sustainable Raw Material for Anti-Bacterial Polyurethane Coatings in Medical Devices

In this study, polyurethane synthesis was carried out using the prepolymer method using the reaction of toluene diisocyanate (TDI) with palm oil-based polyols. To provide heat and anti-bacterial properties in polyurethane coatings, the addition of bentonite (B) and chitosan (K) into polyurethane samples was carried out. The concentration of bentonite and chitosan used were 1.5%, 3.5%, and 5.5%, respectively. Polyurethane-bentonite-chitosan (PU-B-K) samples were analyzed using FTIR to analyze the structure of chemical compounds. Preparation of bentonite purification was carried out by adding cetyltrimethylammonium bromide solution to the bentonite solution. The expected results in this study are the nature of the bacterial resistance produced, while to see the characteristics FTIR tests were performed. Meanwhile, to see the heat resistance TGA test will be performed.

COMPOSITES OF POLYURETHAN BASED ON PALM OIL OIL WITH FILLING MATERIALS BENTONITE-CHITOSAN AS ANTIBACTERIAL COATING ON MEDICAL EQUIPMENT

Modification of polyurethane by adding fillers such as bentonite can improve the physical properties of polyurethane coatings. Polyurethane synthesis is carried out using the prepolymer method by reacting toluene diisocyanate (TDI) with palm oil based polyols. Bentonite addition is used to provide heat resistance in polyurethane coating material. The concentration of bentonite used was 1.5% b / b, 3.5% b / b, and 5.5% b / b. The resulting polyol synthesis will be analyzed using FTIR to see the OH group formed. The bentonite purification process was carried out by using cetyltrimethyl ammonium bromide in bentonite solution. The target in this study is the anti-bacterial properties of the products produced. Whereas to see the characteristics carried out SEM and FTIR analysis.

COMPOSITES OF POLYURETHAN BASED ON PALM OIL OIL WITH FILLING MATERIALS BENTONITE-CHITOSAN AS ANTIBACTERIAL COATING ON MEDICAL EQUIPMENT

Modification of polyurethane by adding fillers such as bentonite can improve the physical properties of polyurethane coatings. Polyurethane synthesis is carried out using the prepolymer method by reacting toluene diisocyanate (TDI) with palm oil based polyols. Bentonite addition is used to provide heat resistance in polyurethane coating material. The concentration of bentonite used was 1.5% b / b, 3.5% b / b, and 5.5% b / b. The resulting polyol synthesis will be analyzed using FTIR to see the OH group formed. The bentonite purification process was carried out by using cetyltrimethyl ammonium bromide in bentonite solution. The target in this study is the anti-bacterial properties of the products produced. Whereas to see the characteristics carried out SEM and FTIR analysis.

Retracted: Synthesis, Characterization, and Surface Activities of Polymeric Cationic Thiol Surfactants in Aqueous Medium

AbstractA series of cationic polyurethane surfactants [PQ8‐18] were synthesized by the reaction of alkyl bromoacetate (namely: octyl‐, decyl‐, dodecyl‐, tetradecyl‐, hexadecyl‐, and octadecyl bromoacetate) as quaternizing agents and modified polyurethane contains tertiary amine species. Modified polyurethane was prepared by the reaction of toluene diisocyanate (TDI) and triethanol amine monomercaptoacetate. The chemical structures of the prepared surfactants were confirmed using elemental analysis, Fourier transform infrared spectroscopy (FTIR), and Proton nuclear magnetic resonance (1H NMR) spectroscopy. The molecular weight measurements of the prepared polymers showed that the segments of each polymer contain average 10 units of the urethane‐triethanol amine mercaptoacetate. The surface activities of the prepared surfactants including: surface tension (γ), effectiveness ( πcmc), concentration at micelle formation (CMC), efficiency (Pc20), maximum concentration at the interface (Γmax), and the average area occupied by each surfactant molecule at the interface at equilibrium ( A min) of surfactants solutions were established at 25°C. The surface tension and the critical micelle concentration values of the prepared surfactants were gradually decreased by the gradual increase of their alkyl chain length. The prepared cationic surfactants showed efficient activity as inhibitors for dissolution of carbon steel in an acidic medium and also as a biocide against the growth of bacteria, fungi, and yeast.

Synthesis, Surface Activities and Anti-Bacterial Activity of (Copper and Nickel) Nanoparticles Stabilized by Cationic Thiol Polyurethane Surfactants

A series of cationic polyurethane surfactant [PQ14, PQ16 and PQ18] were synthesized by the reaction of alkyl bromoacetate (namely: tetradecyl-, hexadecyl- and octadecyl bromoacetate) as quaternizing agents and modified polyurethane contains tertiary amine species. Modified polyurethane was prepared by the reaction of toluene diisocyanate (TDI) and Triethanol amine mono mercaptoacetate. Grinding method is used to synthesize copper and nickel nanoparticles which stabilized by Cationic Thiol polyurethane surfactants. The chemical structures of the prepared surfactants were confirmed using elemental analysis, FTIR, UV and ¹H-NMR spectroscopy. The molecular weight measurements of the prepared polymers showed that the segments of each polymer contain average 10 units of the urethane-Triethanol amine mercaptoacetate. The surface activities of the prepared surfactants including: surface tension (g), effectiveness (π_cmc), concentration at micelle formation (CMC), efficiency (Pc₂₀), maximum concentration at the interface (G_max), average area occupied by each surfactant molecule at the interface at equilibrium (A_min) of surfactants solutions were established at 25°C. The surface tension and the critical micelle concentration values of the prepared surfactants were gradually decreased by the gradual increase of their alkyl chain length. Antimicrobial activity of the synthesized cationic surfactants and their nanostructure with copper and nickel nanoparticles were evaluated against pathogenic bacteria and fungi. The antimicrobial activity showed the enhancement in the antimicrobial activity of the synthesized cationic surfactants in the nanostructures form.

COMPOSITES OF POLYURETHAN BASED ON PALM OIL OIL WITH FILLING MATERIALS BENTONITE-CHITOSAN AS ANTIBACTERIAL COATING ON MEDICAL EQUIPMENT

Modification of polyurethane by adding fillers such as bentonite can improve the physical properties of polyurethane coatings. Polyurethane synthesis is carried out using the prepolymer method by reacting toluene diisocyanate (TDI) with palm oil based polyols. Bentonite addition is used to provide heat resistance in polyurethane coating material. The concentration of bentonite used was 1.5% b / b, 3.5% b / b, and 5.5% b / b. The resulting polyol synthesis will be analyzed using FTIR to see the OH group formed. The bentonite purification process was carried out by using cetyltrimethyl ammonium bromide in bentonite solution. The target in this study is the anti-bacterial properties of the products produced. Whereas to see the characteristics carried out SEM and FTIR analysis

Immobilization of Lipase from Pseudomonas fluorescens on Porous Polyurea and Its Application in Kinetic Resolution of Racemic 1-Phenylethanol.

A porous polyurea (PPU) was prepared through a simple protocol by reacting toluene diisocyanate with water in binary solvent of water-acetone. Its amine group was determined through spectrophotometric absorbance based on its iminization with p-nitrobenzaldehyde amines. PPU was then used as a novel polymer support for enzyme immobilization, through activation by glutaraldehyde followed by immobilization of an enzyme, lipase from Pseudomonas fluorescens (PFL), via covalent bonding with the amine groups of lipase molecules. Influences of glutaraldehyde and enzyme concentration and pH in the process were studied. The results revealed that the activity of the immobilized PFL reached a maximum at GA concentration of 0.17 mol/L and at pH 8. Immobilization rate of 60% or higher for PFL was obtained under optimized condition with an enzyme activity of 283 U/mg. The porous structure of PPU, prior to and after GA activation and PFL immobilization, was characterized. The activity of the immobilized PFL at different temperature and pH and its stability at 40 °C as well as its reusability were tested. The immobilized enzyme was finally used as enantioselective catalyst in kinetic resolution of racemic 1-phenylethanol (1-PEOH), and its performance compared with the free PFL. The results demonstrate that the enzyme activity and stability were greatly improved for the immobilized PFL, and highly pure enantiomers from racemic 1-PEOH were effectively achieved using the immobilized PFL. Noticeable deactivation of PFL in the resolution was observed by acetaldehyde in situ formed. In addition, the immobilized PFL was readily recovered from the reaction system for reuse. A total of 73% of the initial activity was retained after 5 repeated reuse cycles. This work provides a novel route to preparation of a polyurea porous material and its enzyme immobilization, leading to a novel type of immobilized enzyme for efficient kinetic resolution of racemic molecules.

Determination of Polyurethane Foam Growth Kinetics by a Simple Column Height Test

In the present work, the height of foam column has been used to monitor the reaction of the isocyanate group. Kinetic modeling describes the conversion versus time curves. The global reaction can be divided into two different paths: the blowing reaction and the polymerization. The kinetics of the reaction of toluene diisocyanate with a polypropylene glycol has been studied with auxiliary blowing agents; the concentration of NCO and OH groups could be considered equivalent during all the experiments as a model for similar polyurethane systems. Despite the complexity of the system in which different kinetic orders are possible, as well a physically controlled diffusion process, data were fitted to a simple kinetic model of an apparent order. The results obtained have enabled us to propose a reaction path and catalyzed second-order kinetic model.

Preparation and formation mechanism of porous polyurea by reaction of toluene diisocyanate with water and its application as adsorbent for anionic dye removal

A novel and easy one-step protocol for preparation of a new porous material, polyurea (PPU), is reported, which is accomplished through a precipitation polymerization of toluene diisocyanate (TDI) in mixed solvent of H2O-acetone without need for surfactant and porogen. Effects of TDI concentration, mechanical stirring, solvent composition and TDI addition rate on PPU structure are studied. Surface morphology and pore structure of PPU are characterized by scanning electron microscopy and Hg intrusion. Chemical structure of the PPU polymer is investigated using NMR, XRD and FTIR. Mechanism of pore formation is discussed. The obtained PPU is used as adsorbent for anionic dyes adsorption investigation. Two anionic dyes, remazol brilliant blue R and acid fuchsine, are tested. The results indicate that the as-prepared PPU is of high performance in dye adsorption and recycled use. This study provided therefore a facile route to the preparation of a novel and attractive adsorbent candidate for removal of anionic dyes from wastewaters.

One step preparation of porous polyurea by reaction of toluene diisocyanate with water and its characterization

Porous polyurea is synthesized by reacting toluene diisocyanate with water in a water–acetone binary solvent. Materials characterization led to the likely conformations of the polymer chains owing to presence of intensive H-bonding.

Synthesis and characterization of core–shell latex: Effect of fluorinated acrylic monomer on properties of polyacrylates

A series of core–shell latexes were synthesized by seed emulsion polymerization with methyl methacrylate (MMA), butyl acrylate (BA), hydroxyethyl methacrylate (HEMA), methacrylic acid (MAA) and a novel fluorinated monomer, in which process, the novel fluorinated acrylic monomer (FA, reacting toluene diisocyanate with perfluorooctanol and HEMA) was applied in shell. FT–IR and 19F NMR spectra proved that the novel fluorinated acrylic monomer was incorporated into the copolymer chains. TEM and Dynamic light scattering (DLS) analyses demonstrated that latex particles with core–shell structure were obtained, and particle size distribution became broad after adding FA monomer. AFM measurement showed the films prepared from core–shell latexes exhibited different surface roughness; as amount of fluorinated acrylic monomer increased from 0wt% to 12wt% of total monomers in emulsion polymerization, the film surface roughness was enhanced from 0.33nm to 1.67nm, and water contact angle increased with film surface roughness. Thermogravimetric analysis demonstrated that a certain amount of FA monomer was preferable to improve thermal stability of the copolymer. Abrasion test of the films indicated that FA monomer was beneficial to increase abrasion performance of the films.

Preparation of Castor Oil-Based Waterborne Polyurethane and its Application in Electrostatic Copy Paper Surface Enhancing

In order to prepare the polyurethane with less reliance on the oil resources, natural, renewable castor oil was used as raw materials to replace the traditional oil type polyols. The castor oil-based waterborne polyurethane was synthesized by the reaction of toluene diisocyanate (TDI), castor oil (C.O.), dimethylol propionic acid (DMPA) and triethyl amine (TEA). The results revealed that the best paper surface strength properties could be obtained under the condition that the mole ratio of TDI to C.O. was 3.0, prepolymerization temperature was 75°C and dosage of hydrophilic chain extender DMPA was 12.1%. In addition, picking speed of paper surface sized by this emulsion increased 2.53 times compared to the unsized paper, from 0.81m/s to 2.86 m/s, Printing ink absorption value and PPS value reduced in a reasonable scope, 60 s Cobb value was below 30 g/m2.

Toluene Diisocyanate Emission to Air and Migration to a Surface from a Flexible Polyurethane Foam

Flexible polyurethane foam (FPF) is produced from the reaction of toluene diisocyanate (TDI) and polyols. Because of the potential for respiratory sensitization following exposure to TDI, concerns have been raised about potential consumer exposure to TDI from residual 'free TDI' in FPF products. Limited and conflicting results exist in the literature concerning the presence of unreacted TDI remaining in FPF as determined by various solvent extraction and analysis techniques. Because residual TDI results are most often intended for application in assessment of potential human exposure to TDI from FPF products, testing techniques that more accurately simulated human contact with foam were designed. To represent inhalation exposure to TDI from polyurethane foam, a test that measured the emission of TDI to air was conducted. For simulation of human dermal exposure to TDI from polyurethane foam, a migration test technique was designed. Emission of TDI to air was determined for a representative FPF using three different emission test cells. Two were commercially available cells that employ air flow over the surface of the foam [the Field and Laboratory Emission Cell (FLEC®) and the Micro-Chamber/Thermal Extraction™ cell]. The third emission test cell was of a custom design and features air flow through the foam sample rather than over the foam surface. Emitted TDI in the air of the test cells was trapped using glass fiber filters coated with 1-(2-methoxyphenyl)-piperazine (MP), a commonly used derivatizing agent for diisocyanates. The filters were subsequently desorbed and analyzed by liquid chromatography/mass spectrometry. Measurement of TDI migration from representative foam was accomplished by placing glass fiber filters coated with MP on the outer surfaces of a foam disk and then compressing the filters against the disk using a clamping apparatus for periods of 8 and 24 h. The sample filters were subsequently desorbed and analyzed in the same manner as for the emission tests. Although the foam tested had detectable levels of solvent-extractable TDI (56ng TDI g(-1) foam for the foam used in emissions tests; 240-2800ng TDI g(-1) foam for the foam used in migration tests), no TDI was detected in any of the emission or migration tests. Method detection limits (MDLs) for the emissions tests ranged from 0.03 to 0.5ng TDI g(-1) foam (0.002-0.04ng TDI cm(-2) of foam surface), whereas those for the migration tests were 0.73ng TDI g(-1) foam (0.16ng TDI cm(-2) of foam surface). Of the three emission test methods used, the FLEC® had the lowest relative MDLs (by a factor of 3-10) by virtue of its high chamber loading factor. In addition, the FLEC® cell offers well-established conformity with emission testing standard methods.

Role of two stage pyrolysis in fire growth on flexible polyurethane foam slabs

SUMMARYA series of experiments designed to characterize fire behavior on flat 1.2 m × 1.2 m samples of commercial non‐fire‐retarded flexible polyurethane foam were performed. Time‐resolved heat release and mass loss rates were measured. Experimental parameters varied, including foam thickness (5.1 and 10.2 cm) and burning angle (+25°, +12.5°, 0°, −12.5°, and −25°). Polyurethane foam is typically produced by reacting a multifunctional isocyanate with a polyol. The foam used here was formed by reacting toluene diisocyanate and a polyol based on a condensed polyether of polypropylene oxide. Earlier cone calorimeter studies of this foam had revealed a clear two stage pyrolysis behavior in which the heated foam first released a gaseous fuel derived from the isocyanate component, while leaving behind a liquid produced primarily from the polyol, which only gasified and burned following additional heating. The subsequent burning behavior of the polyol‐derived liquid is shown in this work to play a crucial role in the maximum heat release rate and total heat released by the fires spreading across the foam slabs. Published 2013. This article is a U.S. Government work and is in the public domain in the USA.

Epoxy Modified with TDI to Cure Active Hydrogen Groups: Synthesis and Characterization

Study on isocyanate-terminated prepolymer prepared by the reaction of toluene diisocyanate (TDI) with the hydroxy of epoxy resin. By the characteristics that isocyanate-group reacts with active hydrogen groups easily, the prepolymer could be as a curing agent for substance with active hydrogen groups like coal tar. IR spectra showed that the modification was achieved by cross-linking the hydroxy of epoxy resin and the isocyanate of TDI, but epoxy group had no change. In self-made coal tar coatings, the remaining isocyanate-groups played a curing agent role linking coal tar and epoxy resin. Tafel test showed the films with prepolymer was more corrosion resistance, combined the characteristics of the epoxy resin and coal tar.

Isosorbide based chiral polyurethanes: optical and thermal studies

A new class of chiral polyurethanes containing amido linkages in the polymer backbone have been synthesized by reacting toluene diisocyanate with isosorbide (IS) chiral moiety and the chromophores [N,N′-ethane-1,2-diyl bis(6-hydroxy hexanamide), N,N′-butane-1,4-diyl bis(6-hydroxy hexanamide) and N,N′-hexane-1,6-diyl bis(6-hydroxy hexanamide)]. The corresponding chromophores were obtained by the aminolysis of e-caprolactone by using the diamines, diaminoethane, diaminobutane and diaminohexane, respectively. All the polymers were synthesized according to the symmetry conditions so as to obtain the non-centrosymmetric environment. A series of polyurethanes were synthesized by varying the chiral–chromophore composition. The polyurethanes developed were characterized by optical and thermal methods.

SYNTHESIS AND CHEMICAL MODIFICATINON OF NOVOLAC VIA INCORPORATION OF SILICON, PHOSPHOROUS, BORON, SULFUR AND SOME ORGANIC COMPOUNDS

Two types of novolac were prepared, namely / random (o,p-) and (o.o-) novolac. The prepared resins were modified by three methods, the first one includes esterification of phenolic hydroxyl groups in the prepared resins via their treatment with adipoyl chloride and urethane derivative by the reaction of toluene diisocyanate with resins . While the second modification includes incorporation of phosphorous, silicon, and boron into the novolac structure via reaction of P2O5 SiCl2(CH3)2, SiCl2(C6H5)2 and Ba(OH)2 with novolac, Sulfure was incorporated into the novolac structure by preparation of 3,3,5,5 tetra methylo1-4,4-dihydroxy diphenyl sulfone which then reacted with o,o- novolac and the third modification includes reaction of benzyl chloride with sodium salt of novolac and structure contains benzylic ether were obtained. All prepared products were characterized by IR. HNMR, thermal analysis and some physical properties.

Water vapor‐permeable polyurethane ionomer

AbstractThe reaction of toluene diisocyanate with 2,2,3,3‐tetrafluoro‐1‐propanol (fluoro compound) or 3‐glycidoxypropyl trimethoxysilane(siloxane compound) and other additives to form the structure of the fluoro‐based or siloxane‐based polyurethane (PU) ionomer has been proven by infrared spectra. Experimental results indicated that the amount of water vapor permeability of the film made by fluoro‐based or siloxane‐based PU ionomer appeared to gradually increase with increasing concentration of the siloxane compound or fluoro compound, as a result of the formation of more porosities. Our experimental results also showed that the water vapor absorption was seen to be larger for the film made by siloxane‐based PU ionomer film than for the film made by fluoro‐based PU ionomer film, as a result of increased hydrophilic groups attached to the backbone of the PU ionomer molecule. For the film prepared by siloxane‐based PU ionomer, both tensile strength and elongation appeared to increase with an increase in the concentration of siloxane compound. This may be the result of the intermolecular interaction between siloxane‐based PU ionomer molecules themselves, thus enhancing the crosslinking capability of the ionomer molecules. On the other hand, both tensile strength and elongation for the film prepared by fluoro‐based PU ionomer decreased with increasing concentration of the fluoro compound, as a result of intramolecular interaction greatly reducing the crosslinking capability of the ionomer molecules. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 3767–3773, 2006