Chemical Stress Relaxation of NR Networks Prepared in the Swollen State

1986 ◽  
Vol 59 (4) ◽  
pp. 541-550 ◽  
Author(s):  
Kyung-Do Suh ◽  
Hidetoshi Oikawa ◽  
Kenkichi Murakami
Keyword(s):  
Stress Relaxation ◽  
Network Structure ◽  
Three Dimensional ◽  
Polymer Chains ◽  
Chemical Stress ◽  
Network Chain ◽  
Crosslinking Process ◽  
Dimensional Network ◽  
Chemical Relaxation ◽  
The Difference

Abstract From the experimental results of the present investigation, it is apparent that two kinds of networks which have a different three-dimensional network structure give quite different behavior of chemical stress relaxation, even if both networks have the same network chain density. The difference in three-dimensional network structure for the two kinds of rubber arises from the degree of entanglement, which changes with the concentration of the polymer chains prior to the crosslinking process. The direct cause of chemical relaxation is due to the scission of network chains by degradation, whereas the total relaxation is caused by the change of geometrical conformation of network chains. This then casts doubt on the basic concept of chemorheology which is represented by Equation 2.

The Determination of Network Chain Density and the Chemical Stress Relaxation of Crosslinked Polymers

1973 ◽  
Vol 46 (2) ◽  
pp. 477-482
Author(s):  
Saburo Tamura ◽  
Kenkichi Murakami
Keyword(s):  
Stress Relaxation ◽  
Natural Rubber ◽  
Main Chain ◽  
Chemical Stress ◽  
Dicumyl Peroxide ◽  
Constant Independent ◽  
Crosslinked Polymers ◽  
Network Chain ◽  
The Difference ◽  
Entanglement Network

Abstract Both initial network chain densities nM(0) and nS(0) of dicumyl peroxide- cured natural rubbers were determined from the tensile stress and swelling method, respectively. The difference between nM(0) and nS(0) was usually constant, independent of the magnitude of network chain density. That is, it was found that the number of entanglement network chains in the crosslinked natural rubber was usually constant, independent of network chain density. The entanglement network chain density nII(0) was 0.7×10−4 mole/cc. This led to the supposition that the molecular weight between entanglement points Me would be about 9000. Although this value is far from exact, it does not differ too greatly from the value found for noncrosslinked natural rubber. Next, in order to calculate the number of main-chain scissions of crosslinked polymers from their chemical stress relaxation, we proposed our modification of Tobolsky's equation. Using our equation, it was found that the scission of dicumyl peroxide-cured natural rubber occurred in the main chain only. Furthermore, this value agreed with the one obtained from the oxidation of toluene solution of noncrosslinked rubber under the same conditions.

scholarly journals Enhanced bacterial disinfection by CuI–BiOI/rGO hydrogel under visible light irradiation

RSC Advances ◽  
2021 ◽  
Vol 11 (33) ◽  
pp. 20446-20456
Author(s):  
Xi Ma ◽  
Ziwei Wang ◽  
Haoguo Yang ◽  
Yiqiu Zhang ◽  
Zizhong Zhang ◽  
...  
Keyword(s):  
Electron Transport ◽  
Visible Light ◽  
Network Structure ◽  
Visible Light Irradiation ◽  
Three Dimensional ◽  
Light Irradiation ◽  
Transport Capacity ◽  
Highly Efficient ◽  
Dimensional Network ◽  
Bacterial Disinfection

Compared with traditional layered graphene, graphene hydrogels have been used to construct highly efficient visible light-excited photocatalysts due to their particular three-dimensional network structure and efficient electron transport capacity.

scholarly journals Effect of Oat β-Glucan on the Rheological Characteristics and Microstructure of Set-Type Yogurt

Molecules ◽  
2021 ◽  
Vol 26 (16) ◽  
pp. 4752
Author(s):  
Xiaoqing Qu ◽  
Yuliya Nazarenko ◽  
Wei Yang ◽  
Yuanyang Nie ◽  
Yongsheng Zhang ◽  
...  
Keyword(s):  
Sensory Evaluation ◽  
Network Structure ◽  
Theoretical Basis ◽  
Fermentation Process ◽  
Three Dimensional ◽  
Rheological Characteristics ◽  
Fermentation Time ◽  
Spherical Aggregate ◽  
Dimensional Network ◽  
Solid Liquid

The oat β-glucan (OG) was added into set-type yogurt as a functional ingredient, in order to evaluate effects on the rheological characteristics and microstructure of set-type yogurt. When the OG concentration increased from 0 to 0.3%, the WHC gradually increased. At 0.3% OG, the set-type yogurt had the highest WHC of 94.67%. Additionally, the WHC continuously decreased, reaching the lowest WHC (about 80%) at 0.5% OG. When 0.3% OG was added, the highest score of sensory evaluation was about 85. The rheological result showed that the fermentation process went through the changes as follows: solid → liquid → solid → liquid. The addition of 0.3% OG decreased the fermentation time of set-type yogurt by about 16 min, making yogurt more inclined to be liquid. The acidity of set-type yogurt with OG was slightly higher. The result of microstructure showed that the addition of OG destroyed the three-dimensional network structure of yogurt, and some spherical aggregate particles could be clearly observed at 0.3% OG. Overall, this study provided a theoretical basis for the application of OG in set-type yogurt.

4-Bromo-N-(3,4-methylenedioxybenzyl)aniline

2007 ◽  
Vol 63 (11) ◽  
pp. o4404-o4404 ◽  
Author(s):  
Shu-Ping Yang ◽  
Li-Jun Han ◽  
Da-Qi Wang ◽  
Hai-Tao Xia
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonds ◽  
Network Structure ◽  
Title Compound ◽  
Three Dimensional ◽  
Compound C ◽  
Dimensional Network

In the title compound, C14H12BrNO2, the molecules are linked by one C—H...Br hydrogen bond, so forming a C(13) chain running parallel to the [010] direction, and these chains are linked by further C—H...π and C—H...Br hydrogen bonds, resulting in a three-dimensional network structure.

scholarly journals Bis(nitrilotriacetamide-κ4 N,O,O′,O′′)silver(I) nitrate

IUCrData ◽  
2018 ◽  
Vol 3 (1) ◽  
Author(s):  
Min Ren ◽  
Ming Yue ◽  
Jingwen Ran
Keyword(s):  
Hydrogen Bonding ◽  
Network Structure ◽  
Title Compound ◽  
Three Dimensional ◽  
Hydrogen Bonding Interactions ◽  
Dimensional Network

In the centrosymmetric cation of the title compound, [Ag(C6H12N4O3)2]NO3, the AgI ion, lying on a threefold rotoinversion axis, is coordinated by two N atoms and six O atoms from two nitrilotriacetamide ligands, forming a distorted dodecahedral environment. In the crystal, cations and anions are linked through N—H...O hydrogen-bonding interactions, leading to a three-dimensional network structure.

scholarly journals Crystal structure of trihydrogen bis{[1,1,1-tris(2-oxidoethylaminomethyl)ethane]cobalt(III)} trinitrate

2015 ◽  
Vol 71 (12) ◽  
pp. m275-m276 ◽  
Author(s):  
Waqas Sethi ◽  
Heini V. Johannesen ◽  
Thorbjørn J. Morsing ◽  
Stergios Piligkos ◽  
Høgni Weihe
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonding ◽  
Network Structure ◽  
Title Compound ◽  
Rotation Axis ◽  
Three Dimensional ◽  
Rotation Axes ◽  
Dimensional Network ◽  
Nitrate Anions

The title compound, [Co2(L)2]3+·3NO3−[whereL= CH3C(CH2NHCH2CH2OH1/2)3], has been synthesized from the ligand 1,1,1-tris(2-hydroxyethylaminomethyl)ethane. The cobalt(III) dimer has an interesting and uncommon O—H...O hydrogen-bonding motif with the three bridging hydroxy H atoms each being equally disordered over two positions. In the dimeric trication, the octahedrally coordinated CoIIIatoms and the capping C atoms lie on a threefold rotation axis. The N atoms of two crystallographically independent nitrate anions also lie on threefold rotation axes. N—H...O hydrogen bonding between the complex cations and nitrate anions leads to the formation of a three-dimensional network structure. The compound is a racemic conglomerate of crystals containing either D or L molecules. The crystal used for this study is a D crystal.

scholarly journals Tris(1,10-phenanthroline-κ2 N,N′)cobalt(II) bis(2,4,5-tricarboxybenzoate) monohydrate

IUCrData ◽  
2019 ◽  
Vol 4 (1) ◽  
Author(s):  
Kai-Long Zhong ◽  
Guo-Qing Cao ◽  
Wei Song ◽  
Chao Ni
Keyword(s):  
Hydrogen Bonds ◽  
Network Structure ◽  
Rotation Axis ◽  
Complex Cation ◽  
Three Dimensional ◽  
Two Dimensional ◽  
Dimensional Network ◽  
Distorted Octahedral

In the complex cation of the title salt, [Co(C12H8N2)3](C10H5O8)2·H2O, the CoII cation is situated on a twofold rotation axis and is coordinated in a distorted octahedral manner by six N atoms from three chelating 1,10-phenanthroline (phen) ligands. In the crystal, the non-coordinating 2,4,5-tricarboxybenzoate anions interact with each other via O—H...O hydrogen bonds, generating a two-dimensional network parallel to (100). Adjacent sheets are connected by waterO—H...Ocarboxylate hydrogen bonds, resulting in a three-dimensional network structure that surrounds the complex cations.

scholarly journals Crystal structure and hydrogen bonding in the water-stabilized proton-transfer salt brucinium 4-aminophenylarsonate tetrahydrate

2016 ◽  
Vol 72 (5) ◽  
pp. 751-755 ◽  
Author(s):  
Graham Smith ◽  
Urs D. Wermuth
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bond ◽  
Hydrogen Bonding ◽  
Hydrogen Bonds ◽  
Proton Transfer ◽  
Network Structure ◽  
Three Dimensional ◽  
Water Molecules ◽  
Arsanilic Acid ◽  
Dimensional Network

In the structure of the brucinium salt of 4-aminophenylarsonic acid (p-arsanilic acid), systematically 2,3-dimethoxy-10-oxostrychnidinium 4-aminophenylarsonate tetrahydrate, (C23H27N2O4)[As(C6H7N)O2(OH)]·4H2O, the brucinium cations form the characteristic undulating and overlapping head-to-tail layered brucine substructures packed along [010]. The arsanilate anions and the water molecules of solvation are accommodated between the layers and are linked to them through a primary cation N—H...O(anion) hydrogen bond, as well as through water O—H...O hydrogen bonds to brucinium and arsanilate ions as well as bridging water O-atom acceptors, giving an overall three-dimensional network structure.

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