Academic literature on the topic 'Isophorone diisocyanate'

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.

Polyfunctional silylureas were synthesized by the interaction of 3-aminopropyltriethoxysilane with isocyanates of various structures in an inert aromatic solvent. Commercially available diisocyanates such as isophorone diisocyanate, hexamethylene diisocyanate, 2,4-toluene diisocyanate were used as isocyanates. In this case, freshly distilled toluene was used as a solvent. The structures of the obtained compounds were confirmed by the data of IR and NMR1H spectroscopy. Using the synthesized compounds, formulations of compositions for electrodeposition of a tin-indium alloy on a copper wire were developed. The possibility of using silylureas of various structures as effective surfactants used in the electrodeposition of the tin-indium alloy is shown. The operational characteristics of the obtained wire were investigated, including the wire diameter, coating thickness, tensile strength, electrical resistance, and direct current electrical resistivity.

ABSTRACTGelatin can be covalently crosslinked in aqueous solution by application of diisocyanates like L-lysine diisocyanate ethyl ester in order to form hydrogels. Reaction of isocyanate groups with water is however a limiting factor in hydrogel network formation and can strongly influence the outcome of the crosslinking process. Here, diisocyanates with different water solubility and reactivity were applied for the formation of gelatin-based hydrogel networks and the mechanical properties of the hydrogels were investigated to gain a better understanding of starting material/ hydrogel property relations. L-Lysin diisocyanate ethyl ester (LDI), 2,4-toluene diisocyanate (TDI), 1,4-butane diisocyanate (BDI), and isophorone diisocyanate (IPDI) were selected, having different solubility in water ranging from 10-4 to 10-2 mol·L-1. BDI and LDI were estimated to have average reactive isocyanates groups, whereas TDI is highly reactive and IPDI has low reactivity. Formed hydrogels showed different morphologies and were partially very inhomogeneous. Gelation time (1 to 50 minutes), water uptake (300 to 900 wt.-%), and mechanical properties determined by tensile tests (E-moduli 35 to 370 kPa) and rheology (Shear moduli 4.5 to 19.5 kPa) showed that high water solubility as well as high reactivity leads to the formation of poorly crosslinked or inhomogeneous materials. Nevertheless, diisocyanates with lower solubility in water and low reactivity are able to form stable, homogeneous hydrogel networks with gelatin in water.

A series of 1,3-dichloro-2-propanol-blocked diisocyanates, based on diisocyanates including 4,4′-methylene di(phenyl isocyanate), toluene-2,4-diisocyanate, isophorone diisocyanate and 1,6-diisocyanatohexane, were prepared and characterized thoroughly by Fourier transform infrared, 1 H-NMR, 13 C-NMR spectroscopic methods and elemental analysis (CHN). The blocking reaction of 1,3-dichloro 2-propanol with aromatic diisocyanates occurs faster than with the aliphatic isocyanates. The deblocking temperature of blocked isocyanates was determined by thermogravimetric analysis, differential scanning calorimetry and the CO2 evaluation method. Cure reactions of blocked isocyanates with hydroxyl-terminated polybutadiene were also followed to establish the structure–property relationship of the 1,3-dichloro-2-propanol-blocked isocyanates. The deblocking studies reveal that the aromatic isocyanates undergo deblocking more easily than aliphatic isocyanates. The dissolution behavior of 1,3-dichloro-2-propanol-blocked isocyanates in Terathane-2000, polypropylene glycol-2000, polycaprolactone diol-2000 and hydroxyl-terminated polybutadiene-2500 was also studied, and it was found that all adducts are soluble in these polyols.

ABSTRACTPolymer network formation is an important tool for tailoring mechanical properties of polymeric materials. One option to synthesize a network is the addition of bivalent crosslinkers reacting with functional groups present in a polymer. In case of polymer network syntheses based on biopolymers, performing such a crosslinking reaction in water is sometimes necessary in view of the solubility of the biopolymer, such as gelatin, and can be beneficial to avoid potential contamination of the formed material with organic solvents in view of applications in biomedicine. In the case of applying diisocyanates for the crosslinking in water, it is necessary to show that the low molecular weight bifunctional crosslinker has fully reacted, while tailoring of the mechanical properties of the resulting hydrogels is possible despite the complex reaction mechanism. Here, the formation of gelatin-based hydrogel networks with the diisocyanates 2,4-toluene diisocyanate, 1,4-butane diisocyanate, and isophorone diisocyanate is presented. It is shown that extensive washing of materials is required to ensure full conversion of the diisocyanates. The use of different diisocyanates gives hydrogels covering a large range of Young’s moduli (12-450 kPa). The elongations at break (up to 83%) as well as the maximum tensile strengths (up to 410 kPa) of the hydrogels described here are much higher than for lysine diisocyanate ethyl ester crosslinked gelatin reported before. Rheological investigations suggest that the network formation in some cases is due to physical interactions and entanglements rather than covalent crosslink formation.

Four linear polyurea elastomers synthesized from two different diisocyanates, two different chain extenders and a common aliphatic amine-terminated polyether were used as models to investigate the effects of both diisocyanate structure and aromatic disulfide chain extender on hard segmental packing and self-healing ability. Both direct investigation on hard segments and indirect investigation on chain mobility and soft segmental dynamics were carried out to compare the levels of hard segmental packing, leading to agreed conclusions that correlated well with the self-healing abilities of the polyureas. Both diisocyanate structure and disulfide bonds had significant effects on hard segmental packing and self-healing property. Diisocyanate structure had more pronounced effect than disulfide bonds. Bulky alicyclic isophorone diisocyanate (IPDI) resulted in looser hard segmental packing than linear aliphatic hexamethylene diisocyanate (HDI), whereas a disulfide chain extender also promoted self-healing ability through loosening of hard segmental packing compared to its C-C counterpart. The polyurea synthesized from IPDI and the disulfide chain extender exhibited the best self-healing ability among the four polyureas because it had the highest chain mobility ascribed to the loosest hard segmental packing. Therefore, a combination of bulky alicyclic diisocyanate and disulfide chain extender is recommended for the design of self-healing polyurea elastomers.

The environmentally friendly vegetable oil-based waterborne polyurethane–organoclay nanocomposites have been successfully synthesized from castor oil polyols, isophorone diisocyanate and dimethylolpropionic acid.

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Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico
The aim of this work was the preparation of polyols from reactions between castor oil and dietanolamine to increase the hydroxyl content and the network degree in the products to application in electronic devices. The polyols and the mixtures obtained were characterized by nuclear magnetic ressonance. Castor oil (CO) is a natural triglyceride - based polyol possessing hydroxyl groups, which allow several reactions that produce many different products. Among them are the polyurethanes (PU), which have been considered an ideal product for the covering of electricelectronic circuits, due to their excellent electrical, shock-absorbing, solvents resistance and hydrolytic stability properties. About 90% of the fatty acids present in the castor oil are ricinoleic acid (12-hydroxyoleic acid), while the remaining 10% correspond to non-hydroxylated fatty acids, mainly linoleic and oleic acids. The chemical analysis of castor oil indicates a hydroxyl number of 2.7. In this work, a polyol was obtained by the reaction of the CO with diethanolamine (DEA), in order to elevate the hydroxyl value from 160 to 230 or to 280 mgKOH/g, and characterized by nuclear magnetic resonance (NMR) 1H and 13C (Mercury 200). The polyadition of the resulting polyol with isophorone diisocianate (IPDI) was carried out at 60?C, and the reaction kinetics was followed by rheological measurements in a Haake RS150 rheometer. The electrical properties were determined in a HP LCR Meter 4262A, at 1.0 Hz and 10.0 KHz. The chemical analysis showed that the polyols obtained presented hydroxyl number from 230 to 280 mgKOH/g. The polyadition reaction with IPDI produced polyurethane resins with the following properties: hardness in the range from 45 shore A to 65 shore D (ASTM D2240); a dielectric constant of 3.0, at 25?C (ASTM D150). Those results indicate that the obtained resins present compatible properties to the similar products of fossil origin, which are used nowadays for covering electric-electronic circuits. Therefore, the PUs from castor oil can be considered as alternative materials of renewable source, free from the highly harmful petroleum - derived solvents
O presente trabalho teve como objetivo a obten??o de poli?is a partir das rea??es do ?leo de mamona (OM) com dietanolamina (DEA), visando elevar o ?ndice de hidroxila e consequentemente o grau de reticula??o dos produtos finais, cuja aplica??o se destinou ao encapsulamento de circuitos eletroeletr?nicos. A caracteriza??o desses poli?is e respectivas misturas foram feitas utilizando-se a t?cnica da resson?ncia magn?tica nuclear (NMR). O OM (triglicer?deo do ?cido ricinoleico) ? um poliol vegetal natural por apresentar grupo funcional hidroxila que permite v?rias rea??es e produ??o de diferentes produtos. Entre eles est?o as poliuretanas (PU) que t?m sido consideradas como produtos ideais para encapsulamento de componentes de circuitos eletro-eletr?nicos, devido as suas excelentes propriedades com rela??o ? resist?ncia mec?nica e qu?mica. As poliuretanas derivadas do ?leo de mamona podem ser consideradas materiais alternativos de fonte renov?vel e, para as produzidas neste trabalho, n?o foram empregados nenhum tipo de solvente. Cerca de 90% dos ?cidos graxos que comp?em o ?leo de mamona s?o ?cido ricinoleico (?cido 12-hidroxioleico), enquanto os outros 10% s?o ?cidos graxos n?o hidroxilados (?cidos linoleico e oleico). As an?lises qu?micas do ?leo de mamona indicam uma funcionalidade m?dia de 2,7, em rela??o aos grupos hidroxila. A poliadi??o entre o poliol resultante e o isocianato de isoforona (IPDI) teve sua cin?tica aco mpanhada com o aux?lio do re?metro Haake RS 150 ? temperatura de 60 ?C. As propriedades el?tricas foram determinadas em uma ponte HP LCR Meter 4262 A a 1,0 Hz e 10,0 KHz. As an?lises qu?micas mostraram que os poli?is obtidos apresentaram ?ndice de hidroxila entre 230 e 280 mgKOH/g. A rea??o de poliadi??o com IPDI produziu resinas de poliuretana com as seguintes propriedades: dureza entre 45 e 65 shore D (ASTM D2240); constante diel?trica de 3,0 a 25 ?C (ASTM D150). Os resultados, de um modo geral, indicaram que as resinas, cujo extensor de cadeia foi a DEA, apresentaram propriedades compat?veis e em muitos casos superiores, quando comparadas ?s dos produtos atualmente dispon?veis no mercado, sintetizados ? base de trietanolamina (TEA)

Fundação Carlos Chagas Filho de Amparo a Pesquisa do Estado do Rio de Janeiro
Neste estudo, o comportamento em solução diluída de pré-polímeros uretânicos à base de poli(glicol propilênico) (PPG) e diisocianato de isoforona (IPDI) foi avaliado por medidas viscosimétricas a 30 C em dois tipos de solventes, com diferentes polaridades: isopropanol e tolueno. Os pré-polímeros foram sintetizados em massa, ou seja, na ausência de qualquer solvente, e nas formulações foram variadas as razões entre o número de equivalentes-grama de grupamentos isocianato e hidroxila [NCO/OH] e a massa molar do PPG. Os pré-polímeros foram caracterizados por espectrometria na região do infravermelho. No tratamento matemático dos dados viscosimétricos, foram empregadas cinco diferentes equações para determinar os valores de viscosidade intrínseca: Huggins; Kraemer e Schulz-Blaschke, por extrapolação gráfica; e Solomon-Ciuta; Deb-Chanterjee e; novamente, Schulz-Blaschke, para determinações por um único ponto. Os valores de viscosidade intrínseca obtidos pelos dois métodos (extrapolação gráfica e por um único ponto) foram comparados a fim de se verificar a validade da determinação por um único ponto para os sistemas analisados, bem como determinar qual equação seria a mais adequada para esse tipo de cálculo. Foram calculadas as constantes viscosimétricas de Huggins, Kraemer e Schulz-Blaschke, e foi feita uma análise da qualidade do solvente.
In this study the behavior of urethanes prepolymers based on poly(propylene glycol) (PPG) and isophorone diisocyanate (IPDI), in diluted solutions, were studied by viscosimetric measurements, at 30 C, in two types of solvents with different polarities: isopropyl alcohol and toluene. The prepolymers were synthesized in bulk, i.e, in the absence of solvent. In the formulations were varied the ratio between the equivalent-grams number of isocyanate functional groups and hydroxyl group [NCO/OH] and PPG molecular mass. The prepolymers were characterized by infrared spectrometry (FTIR). Five different equations were used to determine intrinsic viscosities values: Huggins; Kraemer and Schulz-Blaschke, by graphic extrapolation; and Solomon-Ciuta; Deb-Chanterjee and; again, Schulz-Blaschke, by a single point determination. The intrinsic viscosities values obtained by two methods (graphic extrapolations and through a single point determination) were compared in order to verify the validity of the single point determination for the systems studied, as well as the more accurate equation for this type of calculation. Viscometric constants from Huggins; Kraemer and Schulz-Blaschke equations were also determined to verify solvent quality.