Synthesis of polymers from isocyanates in polar solvents

Ulrich, H.

doi:10.1002/pol.1976.230110103

Cited by 52 publications

(13 citation statements)

References 123 publications

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“…That is a typical tendency for all kinds of polyurethane foams, not only for these systems. [1][2][3][4][5][6][7][8] As the number of OH groups increase, the crosslinking density of the polyurethane is higher. The percent volume loss also showed a similar tendency with regard to hardness and compression strength.…”

Section: The Effect Of Polyolmentioning

confidence: 99%

“…As their physical properties are varied, the end-products derived from polyurethanes can be used for wide range of applications such as plastics, fibers, elastomers, films, and surface coatings. [1][2][3][4][5][6][7][8] In this study, garnet was used as a filler to give abrading property to polyurethane foam composite. Garnet is an inorganic material having a quite high degree of hardness, which can make it applicable as an abrasive and jewel.…”

Section: Introductionmentioning

confidence: 99%

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Physical properties of garnet-filled polyurethane foam composite

Jang

Kim

Seo

2000

J. Appl. Polym. Sci.

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Section: The Effect Of Polyolmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Physical properties of garnet-filled polyurethane foam composite

Jang

Kim

Seo

2000

J. Appl. Polym. Sci.

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“…Crosslinking reactions were performed using L-lysine diisocyanate ethyl ester (LDI) in water with the application of a surfactant that confers improved solubility for the rather hydrophobic diisocyanate. Although isocyanates preferably react with primary amines to urea derivatives, reaction with water, resulting in the formation of free amines and carbon dioxide and thus allowing further side reactions, must be considered because of the high H 2 O concentration [8,9]. Investigation of the 839 crosslinking mechanism of LDI in water clearly showed the formation of mono-and oligomeric crosslinks as well as grafted species [6].…”

Section: Introductionmentioning

confidence: 96%

Influence of diisocyanate reactivity and water solubility on the formation and the mechanical properties of gelatin-based networks in water

2013

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Gelatin 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.

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“…2,3 Aromatic polyimides have been known for their high-temperature stability, low dielectric properties, and chemical resistance. 4 However, the processability of these polymers is poor due to their infusible and insoluble character.…”

Section: Introductionmentioning

confidence: 99%

Synthesis and characterization of new soluble and thermostable polyimides via novel diisocyanates

1999

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A facile synthesis of two novel diisocyanates containing methylene groups and preformed imide structure is described. Furthermore, six thermally stable and soluble polyimides were synthesized by polycondensation of these two diisocyanates with pyromellitic dianhydride (PMDA), 3,3′,4,4′‐benzophenonetetracarboxylic dianhydride (BTDA) and hexafluoroisopropylidene‐2,2‐bis‐(phthalic anhydride) (6FDA) in N,N‐dimethyl acetamide. All monomers and polymers were characterized by conventional methods and their physical properties such as solution viscosity, solubility properties, thermal stability and thermal behaviour were studied. © 1999 Society of Chemical Industry

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Synthesis of polymers from isocyanates in polar solvents

Cited by 52 publications

References 123 publications

Physical properties of garnet-filled polyurethane foam composite

Physical properties of garnet-filled polyurethane foam composite

Influence of diisocyanate reactivity and water solubility on the formation and the mechanical properties of gelatin-based networks in water

Synthesis and characterization of new soluble and thermostable polyimides via novel diisocyanates

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