Hydrogenation of acrylonitrile–butadiene copolymer latex using water-soluble rhodium catalysts

Liu, Yin; Kim, Hanmiroo; Pan, Qinmin; Rempel, Garry L.

doi:10.1039/c3cy00257h

Cited by 21 publications

(10 citation statements)

References 33 publications

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“…The major signals obtained in the range of 5 to 6 ppm are assigned to the protons on the unsaturated carbon atom and of those obtained at 1.5 to 2.5 ppm is attributed to the aliphatic protons (–CH 3 , –CH 2 , and –CH) of NBR. The peaks at 5.1 and 5.7 ppm in NBR represent the hydrogen atoms of vinyl pendant group, and the peaks at 5.3 to 5.6 ppm are from the protons of 1, 4‐polybutadiene units of rubber . From the figure, it is clear that due to chlorination, the relative intensity of signals of aliphatic protons increased, while that of olefinic protons reduced.…”

Section: Resultsmentioning

confidence: 89%

Synthesis, characterization, processability, mechanical properties, flame retardant, and oil resistance of chlorinated acrylonitrile butadiene rubber

Nihmath

Ramesan

2018

Polymers for Advanced Techs

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Novel chlorinated acrylonitrile butadiene rubber (Cl-NBR) was prepared from NBR by the alkaline hydrolysis of chloroform by using phase-transfer catalysis. The formation of Cl-NBR was monitored by 1 H-NMR, UV-Vis, and Fourier transform infrared spectroscopic techniques. The percentage of chlorine attached to the rubber chain was estimated by Volhard method. The effect of polar groups on the structural and thermal properties of Cl-NBR was analyzed by scanning electron microscopy, X-ray diffraction analysis, differential scanning calorimetry, and thermogravimetric analysis studies. The flame retardant, oil resistance, cure behavior, and mechanical properties of chlorinated elastomer were also analyzed. The proton NMR revealed the attachment of chlorine in the backbone of NBR with new chemical shift values. The C-Cl stretching of chlorinated NBR was confirmed from Fourier transform infrared. The UV spectrum also supported the formation of chlorinated unit in the NBR chain through the shifts and broadening of absorption peaks. The X-ray diffraction analysis pattern indicated a decrease in the amorphous domain of NBR with an increase in the level of chemical modification. The increased glass transition temperature obtained from differential scanning calorimetry confirms the increased molecular rigidity of the chlorinated NBR and thermal transitions increased with increase in the level of chemical modification. The thermal stability of Cl-NBR decreased with an increase in chlorine content. The flame and oil resistance of Cl-NBR was greatly higher than pure NBR due to the increased polarity of modified rubber. The superior tensile strength of Cl-NBR (4 times higher than pure NBR) and higher oil resistance find applications in pump diaphragms, aircraft hoses, oil-lined tubing, and gaskets materials with the excellent flame resistant property.

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Section: Resultsmentioning

confidence: 89%

Synthesis, characterization, processability, mechanical properties, flame retardant, and oil resistance of chlorinated acrylonitrile butadiene rubber

Nihmath

Ramesan

2018

Polymers for Advanced Techs

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“…All samples showed a distinct absorbance around 2236 cm –1 (−CN), and no new absorbances assigned to −NH– appeared after the reaction, implying the 100% selectivity to CC hydrogenation. The characteristic absorbances at 970 cm –1 (1,4-CC) and 920 cm –1 (1,2-CC) are decreased or even disappeared, and a new peak at 723 cm –1 (−(CH 2 ) n – ( n > 4)) appears due to the saturation of CC in HNBR. ,,, The HD of HNBR produced by these catalysts can be calculated from the FTIR spectrum, which is 88.1%, 96.5%, 84.1%, and 96.0%, respectively. The Pd/C–SiO 2 catalyst exhibits the lowest NBR conversion attributed to the extremely low Pd contents and the larger Pd particles as mentioned above.…”

Section: Resultsmentioning

confidence: 99%

“…It is further verified appears due to the saturation of CC in HNBR. 4,7,8,12 The HD of HNBR produced by these catalysts can be calculated from the FTIR spectrum, which is 88.1%, 96.5%, 84.1%, and 96.0%, respectively. The Pd/C−SiO 2 catalyst exhibits the lowest NBR conversion attributed to the extremely low Pd contents and the larger Pd particles as mentioned above.…”

Section: Industrial and Engineering Chemistry Researchmentioning

confidence: 99%

“…The selective hydrogenation of the unsaturated olefin groups (CC) with the retention of nitrile groups (−CN) in nitrile butadiene rubber (NBR) is an effective method to obtain high-quality saturated NBR (HNBR) that exhibits improved thermal properties, and oil and chemical resistance over the original polymer. − With the growing demand for HNBR, the hydrogenation of NBR has attracted significant attention in industries. Generally, HNBR is produced by either homogeneous or heterogeneous catalytic hydrogenation of NBR .…”

Section: Introductionmentioning

confidence: 99%

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A Surface-Cofunctionalized Silica Supported Palladium Catalyst for Selective Hydrogenation of Nitrile Butadiene Rubber with Enhanced Catalytic Activity and Recycling Performance

Chen

Liu

et al. 2019

Ind. Eng. Chem. Res.

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A cofunctionalized silica-supported palladium catalyst has been successfully designed and controllably fabricated for the selective hydrogenation of nitrile butadiene rubber (NBR). The amino groups on the surface can anchor and stabilize Pd particles via the strong coordination with diamine ligands and methyl groups can enhance surface hydrophobicity, weakening the adhesion of NBR/hydrogenated NBR on catalyst and accelerating the desorption of product to re-expose the active sites. The cofunctionalized catalyst with small-sized and well-dispersed Pd particles exhibits an enhanced activity and stability, which can be easily recycled by filtration and reused without any treatment. It remains a high activity and 100% selectivity to CC after recycling five times, and only a slight loss of Pd is detected in products. Such catalyst with cofunctionalized surface is very efficient for NBR hydrogenation and also can be applied to other catalytic systems to tune their selectivity, activity, and reusability.

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“…Generally, rhodium and ruthenium catalysts are commonly employed. Liu et al explored the hydrogenation of NBR latex using water-soluble rhodium based catalysts RhCl(TPPMS) 3 and RhCl(TPPTS) 3 [22]. In the absence of organic solvents, the hydrogenation degree of 0.052 mmol/L RhCl(TPPMS) 3 reached about 95 mol% in 8.5 h at 100 • C under 1000 psi H 2 pressure, whereas RhCl(TPPTS) 3 showed low reaction activity, meaning a high degree of hydrogenation could not be achieved.…”

Section: Introductionmentioning

confidence: 99%

Hydrogenation of Carboxyl Nitrile Butadiene Rubber Latex Using a Ruthenium-Based Catalyst

Liu

Zhou

et al. 2022

Catalysts

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Hydrogenated carboxyl nitrile rubber (HXNBR) is endowed with superior mechanical performance and heat–oxygen aging resistance via emulsion hydrogenation of its precursor, i.e., carboxyl nitrile rubber (XNBR). Herein, a ruthenium-based catalyst was prepared to achieve the direct catalytic hydrogenation of XNBR latex. The effects of a series of hydrogenation conditions, such as catalyst dosage, solid content and reaction temperature, as well as the hydrogen pressure, on the hydrogenation reaction were investigated in detail. We found that the hydrogenation rate fell upon increasing the solid content of the XNBR latex, with an XNBR conversion rate of 95.01 mol% in 7 h with 11.25 wt% solid content. As the reaction temperature was increased, the hydrogenation rate first increased and then decreased. The fastest reaction hydrogenation rate was reached at 140 °C, with an XNBR conversion of 95.10 mol% in 5 h. The hydrogenation rate was positively related with the hydrogen pressure employed in the reactor. In view of the safety and cost, a pressure rate of 1300 psi was considered optimal. Similarly, the hydrogenation rate can also be enhanced by adding more catalyst. When 0.05 wt% catalyst was added, the fastest hydrogenation rate was achieved. In summary, the following optimum hydrogenation conditions were determined by using a synthesized ruthenium-based catalyst: 11.25 wt% solid content of XNBR latex, 140 °C of reaction temperature, 1300 psi of hydrogen pressure and 0.05 wt% catalyst. The vulcanization, mechanical performance, aging resistance and oil resistance of the produced HXNBR under the above reaction conditions were systematically investigated.

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Hydrogenation of acrylonitrile–butadiene copolymer latex using water-soluble rhodium catalysts

Cited by 21 publications

References 33 publications

Synthesis, characterization, processability, mechanical properties, flame retardant, and oil resistance of chlorinated acrylonitrile butadiene rubber

Synthesis, characterization, processability, mechanical properties, flame retardant, and oil resistance of chlorinated acrylonitrile butadiene rubber

A Surface-Cofunctionalized Silica Supported Palladium Catalyst for Selective Hydrogenation of Nitrile Butadiene Rubber with Enhanced Catalytic Activity and Recycling Performance

Hydrogenation of Carboxyl Nitrile Butadiene Rubber Latex Using a Ruthenium-Based Catalyst

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