scholarly journals Improved high-temperature damping performance of nitrile-butadiene rubber/phenolic resin composites by introducing different hindered amine molecules

e-Polymers ◽  
2020 ◽  
Vol 20 (1) ◽  
pp. 482-490
Author(s):  
Meng Song ◽  
Xiulin Yue ◽  
Xiujuan Wang ◽  
Mengjie Huang ◽  
Mingxing Ma ◽  
...  

AbstractBy introducing hindered amine GW-622 or GW-944 into nitrile-butadiene rubber/phenolic resin (NBR/PR, abbreviated as NBPR) matrix, we have prepared different hindered amine/NBR/PR ternary hybrid damping materials with high-temperature damping performance, respectively. Fourier transform infrared (FTIR) spectroscopy, scanning electron microscope (SEM), differential scanning calorimetry (DSC), and dynamic thermomechanical analysis (DMA) were used to research the microstructure, compatibility, and damping properties of the hindered amine/NBPR composites. FTIR results indicate that hydrogen bonds are formed between the hindered amine and the NBPR matrix. Both DSC and SEM results show that hindered amine has partial compatibility with the NBPR matrix. DMA results show that two loss peaks appear in the hindered amine/NBPR composite. Thereby, the composites show better damping performance at a higher temperature, and the temperature domain of high-temperature damping becomes wider with the increase in the addition of hindered amine. This study provides a theoretical support for the preparation of high-temperature damping materials.

e-Polymers ◽  
2019 ◽  
Vol 20 (1) ◽  
pp. 8-15 ◽  
Author(s):  
Meng Song ◽  
Xiujuan Wang ◽  
Sizhu Wu ◽  
Qi Qin ◽  
Guomin Yu ◽  
...  

AbstractDifferent hindered amines, GW-622 and GW-944, were added to a nitrile-butadiene rubber (NBR) matrix to prepare a hybrid damping material. The microstructure, compatibility, and dynamic mechanical properties of the hindered amine/NBR composites were investigated using Fourier transform infrared (FTIR) spectroscopy, scanning electron microscope (SEM), differential scanning calorimetry (DSC), and dynamic thermomechanical analysis (DMA). The FTIR results showed that hydrogen bonds formed between the hindered amine molecules and the NBR matrix. The SEM and DSC results showed that both GW-622 and GW-944 had partial compatibility with the NBR matrix, and a two-phase structure appeared. The effective damping temperature ranges of the hindered amine/NBR composites were narrow at room temperature and broad at higher temperatures with increasing amounts of GW-622 and GW-944. Comparatively, the damping effect from the addition of GW-944 molecules was more clearly. The present work provides a theoretical basis for the preparation of optimum damping rubber materials.


2020 ◽  
Vol 2020 ◽  
pp. 1-15
Author(s):  
Young Il Moon ◽  
Jae Kap Jung ◽  
Ki Soo Chung

The dielectric permittivity of synthetic rubber polymers, nitrile butadiene rubber (NBR) and ethylene propylene diene monomer (EPDM), with both frequency and temperature variations, was thoroughly investigated by dielectric relaxation spectroscopy (DRS). The spectrum versus frequency of DRS was analyzed with the semiempirical Havriliak–Negami formula and conductivity contribution by employing the newly developed “dispersion analyzer” analysis program. The main dielectric relaxations called the α- and β-processes, associated with the cooperative motion of chains in polymers, were discovered in the low-temperature region. In the high-temperature region, we found Maxwell–Wagner–Sillars (MWS) relaxation associated with polymer interfacing and normal-mode (α’) relaxation responsible for end-to-end dipole vector motion. The activation energies of schematic molecular chains responsible for the relaxation processes were obtained with the information about its motional mode. The glass transition temperature and dipole moment for the side group were also determined and compared with those from previous studies. In the EPDM specimen, the peaks of α- and β-relaxation merged at high temperature and were separated with decreasing temperature. The first observations of both merging and splitting were consistent with the results on the temperature dependency of the relaxation strength. Both contour mapping and three-dimensional plots for the two rubbers provide visual information for the distribution and mapping of relaxation.


2011 ◽  
Vol 335-336 ◽  
pp. 120-123 ◽  
Author(s):  
Chang Su ◽  
Pan He ◽  
Li Huan Xu ◽  
Cheng Zhang

In this article, the damping mechanism of organic hybrids consisting of Nitrile Butadiene Rubber (NBR) and phenolic oligomer 4-methyl-pheno reaction products of both dicyclopentadiene and isobutylene (MPDI) were investigated by dynamic mechanical analysis (DMA). It was shown that NBR/MPDI blends exhibit only one damping peak, which shifted to higher temperature with the increase of MPDI content, and the maximum of tan δ peak decreased slightly when the ratio of NBR/MPDI was no more than 100/20, and then increased when the ratio rised from 100/20 to 100/80. Fourier transform infrared spectrum (FT-IR) showed that the hydrogen bond were formed between -OH of MPDI and a-H of NBR. X-ray diffraction (XRD) and differential scanning calorimetry (DSC) measurements indicated that MPDI exhibit amorphous features, which was compatible with the blends. These may imply that much more stable damping material with both higher tan δ peak and controllable damping peak position can be achieved.


2011 ◽  
Vol 110-116 ◽  
pp. 3818-3824
Author(s):  
Xiao Ping Wang ◽  
De Min Jia ◽  
An Min Huang

Organo-montmorillonite (OMMT) was compounded with Hydrogenated Nitrile-Butadiene Rubber (HNBR)(50% epoxidation) to prepare nanocomposites by melt mixing method. The nanometer scales of organoclays in rubber matrix were determined by X-ray diffraction testing, the exfoliated/intercalated structures of OMMT in HNBR were confirmed by transmission elector microscopy. The increases in tensile module and strength of HNBR/OMMT nanocomposites vulcanizaters were caused by the better interactions between rubber macromolecule chains and organoclay layers. The air-aging properties of nanocomposites enhanced by the increasing content of OMMT, which was leaded by the barrier characterize of nanodisperse OMMT layers. DMA test showed that the Tgs of HNBR/OMMT shifted to a higher temperature, as verified by the crosslinking density determination.


1996 ◽  
Vol 8 (3) ◽  
pp. 407-426 ◽  
Author(s):  
J P Habas ◽  
M F Grenier-Loustalot ◽  
J Peyrelasse

Of the thermostable polymers on the market the American PMR-15 resin is a reference compound. Nevertheless, its defects have necessitated the development of new polymers such as IP960. The object of this work is to characterize IP960 which is soluble in the diglyme until the imide oligomer stage. HPLC and 1H NMR analyses of the prepolymer demonstrate its polymolecularity. Several isomer forms, due to possible conformations of the nadimide endcaps, are present in equal amounts in the medium. The combined use of differential scanning calorimetry and rheological techniques have allowed us to study and to explain the evolution of properties of the prepolymer with temperature (glass transition, crosslinking etc). Using FTIR spectroscopy, we have studied the structure of the polymer network. Our results seem to confirm the validity of the crosslinking diagram of nadic structures proposed by Wong and co-workers. Thermomechanical analysis of the crosslinked compound shows that the Tg of the polymer is close to 292 °C. It also reveals on the curb of the modulus G″, namely the presence of two peaks γ and β associated with secondary mechanical relaxations within macromolecular chains ( Tγ = −102 °C; Tβ =68 °C).


e-Polymers ◽  
2007 ◽  
Vol 7 (1) ◽  
Author(s):  
Blaž Likozar ◽  
Matjaž Krajnc

AbstractThe viscoelastic behavior of hydrogenated nitrile butadiene rubber (HNBR) was studied over a range of temperatures and shear frequencies. Dynamic mechanical properties were studied and modelled using the generalized Maxwell model and the Williams-Landel-Ferry equation. A fitting algorithm was developed to provide the best agreement between the experimental data and the model results. In addition to dynamic mechanical analysis (DMA), differential scanning calorimetry (DSC) was applied. The HNBR structure was characterized by X-ray diffraction (XRD). The developed model exhibited an excellent agreement with either isothermal or dynamic experiment data, yet only up to the rubbery plateau, after which a structure ordering occurred. This was explained by the cyano group secondary bonding and consequentially the cross-linking between HNBR chains. A molecular modeling simulation was made to confirm the cross-linking. The effect of peroxide cross-linking agents in a compound resembled the one usually observed in the filler formulated compounds.


2013 ◽  
Vol 33 (9) ◽  
pp. 837-842
Author(s):  
Jia-Qi Luo ◽  
Bin Yang ◽  
Ru Xia ◽  
Guo-Jun Cheng ◽  
Yu-Chuan Zhang ◽  
...  

Abstract Blends of nitrile butadiene rubber (NBR) and polyoxymethlene (POM) were prepared by melt mixing, with a polyether polyol (Model KGF400D) used as the compatibilizer. Scanning electron microscopy (SEM) was used to characterize the cryogenically fractured surfaces of the blends clearly, which showed that the compatibility of NBR/POM blends was significantly enhanced with the addition of KGF400D. Both differential scanning calorimetry (DSC) and rubber process analysis (RPA) results clearly indicated the mechanism of compatibility improvement. Dual functions of KGF400D within the NBR/POM blends were found: one was the lubrication effect and the other was the hydrogen bonding between the hydroxyl of KGF400D and ether oxygen group of POM or lone pair electron in the cyano group of NBR.


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