Mechanism for Peroxide Cross-Linking of EPDM Rubber from MAS13C NMR Spectroscopy

2009 ◽  
Vol 42 (22) ◽  
pp. 8914-8924 ◽  
Author(s):  
R. A. Orza ◽  
P. C. M. M. Magusin ◽  
V. M. Litvinov ◽  
M. van Duin ◽  
M. A. J. Michels
Keyword(s):  
Nmr Spectroscopy ◽  
Cross Linking ◽  
Epdm Rubber

Evidence for cross-linking in tomato cutin using HR-MAS NMR spectroscopy

2003 ◽  
Vol 64 (6) ◽  
pp. 1163-1170 ◽  
Author(s):  
Ashish P. Deshmukh ◽  
André J. Simpson ◽  
Patrick G. Hatcher
Keyword(s):  
Nmr Spectroscopy ◽  
Mas Nmr ◽  
Cross Linking

Chemical Cross-Linking Gelatin with Natural Phenolic Compounds as Studied by High-Resolution NMR Spectroscopy

2010 ◽  
Vol 11 (4) ◽  
pp. 1125-1132 ◽  
Author(s):  
Xiaoqing Zhang ◽  
My Dieu Do ◽  
Philip Casey ◽  
Adrian Sulistio ◽  
Greg G. Qiao ◽  
...  
Keyword(s):  
Phenolic Compounds ◽  
Nmr Spectroscopy ◽  
High Resolution ◽  
Cross Linking ◽  
High Resolution Nmr ◽  
Natural Phenolic Compounds ◽  
Chemical Cross Linking

scholarly journals 17O NMR spectroscopy-assisted in vitro bioactivity studies of the intermediates formed via Na2S and RSNO cross-linking reactions

RSC Advances ◽  
2020 ◽  
Vol 10 (65) ◽  
pp. 39617-39626
Author(s):  
Xingyu Zhu ◽  
Yin Gao
Keyword(s):  
Cell Culture ◽  
Nmr Spectroscopy ◽  
Cross Linking ◽  
In Vitro Bioactivity ◽  
17O Nmr ◽  
17O Nmr Spectroscopy

By using UV-Vis, 15N NMR and 17O NMR spectroscopy techniques, we characterized the intermediates (SSNO− and SNO−) obtained from RSNO and Na2S cross-linking reaction. We found that SSNO− could serve as NO reservoir in cell culture experiments.

scholarly journals Aliphatic β-Nitroalcohols for Therapeutic Corneoscleral Cross-Linking: Chemical Stability Studies Using1H-NMR Spectroscopy

2013 ◽  
Vol 90 (2) ◽  
pp. 338-343
Author(s):  
Xia Li ◽  
Yongjun Li ◽  
MiJung Kim ◽  
Stephen L. Trokel ◽  
Nicholas J. Turro ◽  
...  
Keyword(s):  
Nmr Spectroscopy ◽  
Chemical Stability ◽  
Cross Linking ◽  
Stability Studies

scholarly journals Thermodynamic and structural characterization of 2′-nitrogen-modified RNA duplexes

2004 ◽  
Vol 32 (11) ◽  
pp. 3446-3455 ◽  
Author(s):  
John W. Pham ◽  
Ishwar Radhakrishnan ◽  
Erik J. Sontheimer
Keyword(s):  
Molecular Modeling ◽  
Nmr Spectroscopy ◽  
Nucleic Acids ◽  
Chemical Modification ◽  
Structural Characterization ◽  
Cross Linking ◽  
Base Pairing ◽  
Alkyl Groups ◽  
Rna Duplexes

Abstract 2′-aminonucleosides are commonly used as sites of post-synthetic chemical modification within nucleic acids. As part of a larger cross-linking strategy, we appended alkyl groups onto the N2′ position of 2′-amino-modified RNAs via 2′-ureido and 2′-amido linkages. We have characterized the thermodynamics of 2′-amino, 2′-alkylamido and 2′-alkylureido-modified RNA duplexes and show that 2′-ureido-modified RNAs are significantly more stable than analogous 2′-amido-modified RNAs. Using NMR spectroscopy and NMR-based molecular modeling of 2′-modified RNA duplexes, we examined the effects that 2′-nitrogen modifications have on RNA helices. Our data suggest that the 2′-ureido group forms a specific intra-nucleoside interaction that cannot occur within 2′-amido-modified helices. These results indicate that 2′-ureido modifications are superior to analogous 2′-amido ones for applications that require stable base pairing.

scholarly journals A Method to Improve the Characteristics of EPDM Rubber Based Eco-Composites with Electron Beam

Polymers ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 215 ◽  
Author(s):  
Gabriela Craciun ◽  
Elena Manaila ◽  
Daniel Ighigeanu ◽  
Maria Daniela Stelescu
Keyword(s):  
Electron Beam ◽  
Electron Beam Irradiation ◽  
Natural Fiber ◽  
Sol Gel ◽  
Mechanical Tests ◽  
Cross Linking ◽  
Atmospheric Conditions ◽  
Epdm Rubber ◽  
Reinforced Composite ◽  
Physical And Chemical

A natural fiber reinforced composite, belonging to the class of eco composites, based on ethylene-propylene-terpolymer rubber (EPDM) and wood wastes were obtained by electron beam irradiation at 75, 150, 300, and 600 kGy in atmospheric conditions and at room temperature using a linear accelerator of 5.5 MeV. The sawdust (S), in amounts of 5 and 15 phr, respectively, was used to act as a natural filler for the improvement of physical and chemical characteristics. The cross-linking effects were evaluated through sol-gel analysis, mechanical tests, and Fourier Transform Infrared FTIR spectroscopy comparatively with the classic method with dibenzoyl peroxide (P) applied on the same types of samples at high temperature. Gel fraction exhibits values over 98% but, in the case of P cross-linking, is necessary to add more sawdust (15 phr) to obtain the same results as in the case of electron beam (EB) cross-linking (5 phr/300 kGy). Even if the EB cross-linking and sawdust addition have a reinforcement effect on EPDM rubber, the medium irradiation dose of 300 kGy looks to be a limit to which or from which the properties of the composite are improved or deteriorated. The absorption behavior of the eco-composites was studied through water uptake tests.

Mechanism of Peroxide Cross-Linking of EPDM Rubber

2010 ◽  
Vol 291-292 (1) ◽  
pp. 66-74 ◽  
Author(s):  
Martin van Duin ◽  
Ramona Orza ◽  
Ron Peters ◽  
Victor Chechik
Keyword(s):  
Cross Linking ◽  
Epdm Rubber

scholarly journals Polymer Networks Synthesized from Poly(Sorbitol Adipate) and Functionalized Poly(Ethylene Glycol)

Gels ◽  
2021 ◽  
Vol 7 (1) ◽  
pp. 22
Author(s):  
Haroon Rashid ◽  
Yury Golitsyn ◽  
Muhammad Humayun Bilal ◽  
Karsten Mäder ◽  
Detlef Reichert ◽  
...  
Keyword(s):  
Nmr Spectroscopy ◽  
Ethylene Glycol ◽  
Polymer Networks ◽  
Coupling Constants ◽  
Cross Linking ◽  
Magic Angle ◽  
Poly Ethylene Glycol ◽  
Component Structure ◽  
Degree Of Swelling ◽  
Poly Ethylene

Polymer networks were prepared by Steglich esterification using poly(sorbitol adipate) (PSA) and poly(sorbitol adipate)-graft-poly(ethylene glycol) mono methyl ether (PSA-g-mPEG12) copolymer. Utilizing multi-hydroxyl functionalities of PSA, poly(ethylene glycol) (PEG) was first grafted onto a PSA backbone. Then the cross-linking of PSA or PSA-g-mPEG12 was carried out with disuccinyl PEG of different molar masses (Suc-PEGn-Suc). Polymers were characterized through nuclear magnetic resonance (NMR) spectroscopy, gel permeation chromatography (GPC), and differential scanning calorimetry (DSC). The degree of swelling of networks was investigated through water (D2O) uptake studies, while for detailed examination of their structural dynamics, networks were studied using 13C magic angle spinning NMR (13C MAS NMR) spectroscopy, 1H double quantum NMR (1H DQ NMR) spectroscopy, and 1H pulsed field gradient NMR (1H PFG NMR) spectroscopy. These solid state NMR results revealed that the networks were composed of a two component structure, having different dipolar coupling constants. The diffusion of solvent molecules depended on the degree of swelling that was imparted to the network by the varying chain length of the PEG based cross-linking agent.

scholarly journals Functionalization of polyhydromethylsiloxane with nitrogen-containing organic compounds

2021 ◽  
Vol 28 (5) ◽  
Author(s):  
Maria Owińska ◽  
Aleksandra Chechelska-Noworyta ◽  
Zbigniew Olejniczak ◽  
Magdalena Hasik
Keyword(s):  
Nmr Spectroscopy ◽  
Ftir Spectroscopy ◽  
Organic Compounds ◽  
Elemental Analysis ◽  
Functionalized Polymers ◽  
Cross Linking ◽  
Hydrosilylation Reaction ◽  
Silanol Groups ◽  
Mild Conditions ◽  
Hydrolysis Of

AbstractLinear polyhydromethylsiloxane (PHMS) was functionalized with nitrogen-containing organic compounds: N-allylaniline (Naa), N-allylcyclohexylamine (Nach), N-allylpiperidine (Nap) and 4-vinylpyridine (4VP) via hydrosilylation reaction in the presence of Pt0 complex (Karstedt’s catalyst) under mild conditions. Reaction course was followed by FTIR spectroscopy and final hydrosilylation products were characterized by FTIR, 1H, 29Si NMR and 29Si MAS-NMR spectroscopies as well as by elemental analysis. Results showed that functionalization of PHMS with N-allyl amines took place but in none of the systems it was complete. Hydrosilylation of Naa, Nach and Nap with PHMS led both, to the β and α addition products. 29Si NMR spectroscopy showed unequivocally that the reaction of PHMS with 4VP did not occur and the only reactions in the systems were hydrolysis of Si–H groups of PHMS followed by condensation of the silanol groups resulting in cross-linking of the polymer. All the functionalized polymers studied in the work contained reactive amine moieties prone to further modifications, therefore exhibit a great potential for various applications.

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