scholarly journals Functional Modification Effect of Epoxy Oligomers on the Structure and Properties of Epoxy Hydroxyurethane Polymers

2018 ◽  
Vol 2018 ◽  
pp. 1-16 ◽  
Author(s):  
Victor Stroganov ◽  
Oleg Stoyanov ◽  
Ilya Stroganov ◽  
Eduard Kraus
Keyword(s):  
Formation Processes ◽  
Intermolecular Hydrogen Bonds ◽  
Epoxy Oligomers ◽  
Epoxy Polymers ◽  
Ir And Nmr Spectroscopy ◽  
Epoxy Amine ◽  
Hydrogen Bond System ◽  
Bond System ◽  
Network Operation ◽  
Competing Reactions

We introduce different ways to solve the actual fragility problem of the epoxy-amine polymers by curing epoxidian oligomers with aliphatic amines without additional heat input. The pathways are the oligomer-oligomeric modification of epoxy resins-epoxy oligomers (EO), with their conversion to oligoethercyclocarbonates (OECC) by carbonization with carbon dioxide. The cocuring of these oligomers as a result of aminolysis competing reactions is “epoxide-amine” (forming a network polymer) and “cyclocarbonate-amine” (forming the linear hydroxyurethane, extending the internodal chains). Formation of internal and intermolecular hydrogen bonds was established on hydroxycarbonates (HA) and linear polyhydroxyurethanes (PHU) model compounds by IR and NMR spectroscopy. The results of the hydrogen bond system formation processes explain the change in the relaxation and physicomechanical properties of hard polymers modified by the epoxy-amine compositions (OECC), containing aromatic and aliphatic links. This paper presents a possible OECC modificator, the optimal EO:OECC ratio and its influence on the cross-link frequency, the polarity, the fragment and chain flexibilities and, as a consequence, the possible stiffness regulation for selected epoxy polymers. Thus, the causes of the increase in deformation-strength and adhesion characteristics were established by a factor of 1.5 to 3.0 due to an increase in cohesive strength (as a result of the combined network operation with covalent and physical bonds), as well as reduction of residual stresses (by adding the aliphatic fragments as additional relaxants), and reducing the defectiveness of the boundary layers (polymer-substrate).

Pyridine 1:1 adducts of urea (Z′ = 1) and thiourea (Z′ = 8)

2018 ◽  
Vol 74 (4) ◽  
pp. 406-410 ◽  
Author(s):  
Mark Strey ◽  
Peter G. Jones
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonds ◽  
Layer Structure ◽  
Urea Adduct ◽  
Standard Type ◽  
Space Group ◽  
Hydrogen Bond System ◽  
Bond System ◽  
Bifurcated Hydrogen Bond ◽  
Urea Adducts

During our studies of urea and thiourea adducts, we noticed that no adducts with unsubstituted pyridine had been structurally investigated. The 1:1 adduct of pyridine and urea, C5H5N·CH4N2O, crystallizes in the P21/c space group with Z = 4. The structure is of a standard type for urea adducts, whereby the urea molecules form a ribbon, parallel to the a axis, consisting of linked R 2 2(8) rings, and the pyridine molecules are attached to the periphery of the ribbon by bifurcated (N—H...)2N hydrogen bonds. The 1:1 adduct of pyridine and thiourea, C5H5N·CH4N2S, crystallizes in the P21/n space group, with Z = 32 (Z′ = 8). The structure displays similar ribbons to those of the urea adduct. There are two independent ribbons parallel to the b axis at z ≃ 0 and 1 \over 2, and three at z ≃ 1 \over 4 and 3 \over 4; the latter are crosslinked to form a layer structure by additional long N—H...S interactions, which each formally replace one branch of a bifurcated hydrogen-bond system.

Synthesis of Epoxy Nanocomposites

2021 ◽  
pp. 225-260
Author(s):  
Tamara F. Irzhak ◽  
Vadim I. Irzhak
Keyword(s):  
Carbon Nanotubes ◽  
Functional Properties ◽  
Mutual Effect ◽  
High Reactivity ◽  
Formation Processes ◽  
Epoxy Nanocomposites ◽  
Epoxy Oligomers ◽  
Composite Formation ◽  
Curing Agents ◽  
Epoxy Groups

The formation processes of epoxy nanocomposites with carbon (nanotubes, graphene, and graphite), metal-containing, and aluminosilicate (montmorillonite and halloysite tubes) fillers are considered. A high reactivity of epoxy groups and a thermodynamic miscibility of epoxy oligomers with many substances make it possible to use diverse curing agents and to accomplish curing reactions under various technological conditions. Epoxy nanocomposites are designed to realize to the same extent the unique functional properties of nanoparticles: electric, magnetic, optical, chemical, and biological. The mutual effect of both a matrix and nanoparticles on the composite formation is discussed.

{Bis[2-(3,5-dimethylpyrazol-1-yl)ethyl]amine-κ2 N,N′}dichloridozinc(II) methanol solvate

2007 ◽  
Vol 63 (11) ◽  
pp. m2679-m2679 ◽  
Author(s):  
Rae Eun Lee ◽  
Yeon Do Park ◽  
Jong Hwa Jeong
Keyword(s):  
Hydrogen Bond ◽  
Dihedral Angle ◽  
Title Compound ◽  
Solvent Molecule ◽  
Hydrogen Bond System ◽  
Bond System ◽  
Cl Atoms ◽  
Ethyl Amine

In the title compound, [ZnCl2(C14H23N5)]·CH3OH, the Zn atom is coordinated by two N atoms and two Cl atoms in an approximately tetrahedral arrangement. The dihedral angle between the N—Zn—N and Cl—Zn—Cl planes is 89.69 (5)°. The methanol solvent molecule takes part in the formation of the hydrogen-bond system.

scholarly journals Nickel alendronate

2012 ◽  
Vol 68 (6) ◽  
pp. m820-m821 ◽  
Author(s):  
Małgorzata Sikorska ◽  
Maria Gazda ◽  
Jaroslaw Chojnacki
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bond ◽  
Hydrogen Bonds ◽  
Water Molecule ◽  
Title Compound ◽  
Intermolecular Hydrogen Bond ◽  
Hydrothermal Conditions ◽  
Complex Molecules ◽  
Hydrogen Bond System ◽  
Bond System

The title compound {systematic name: bis(μ2-dihydrogen 4-azaniumyl-1-hydroxybutane-1,1-diphosphonato)bis[aqua(dihydrogen 4-azaniumyl-1-hydroxybutane-1,1-diphosphonato)nickel(II)] dihydrate}, [Ni2(C4H12NO7P2)4(H2O)2]·2H2O, was synthesiized under hydrothermal conditions. Its structure is isotypic with the CoII analogue. The crystal structure is built up from centrosymmetric dinuclear complex molecules and the structure is reinforced by a net of intermolecular O—H...O and N—H...O hydrogen bonds. One water molecule is bound to the NiII atom in the octahedral coordination sphere, while the second is part of the intermolecular hydrogen-bond system.

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