Abstract:The effects of three curing systems, peroxide, peroxide-phenolic combination, and phenolic on selected properties of cured carbon black-filled ethylene-propylene-diene monomer rubber (EPDM) were investigated. The cured rubbers immersed in hot amine solution to evaluate their suitability for seal and gasket industry at elevated temperature and amine environments. These tests were essential for evaluating the durability of the gasket in a gas refinery. The Fourier transform infrared spectroscopy spectrums reveal… Show more
“…The Fourier transform infrared spectroscopy (FTIR) graphs used to identify the existence of the phenolic resin in the structure of the waste bladder butyl rubber powder (Figure 3). As observed, the appeared peaks at 3412,1539,1621,1180, and 715 𝑐𝑚 −1 attributed to phenolic hydroxyl (OH), C=C in aromatic ring, the original IR band of the aromatic ring, C-O-C (ether crosslink), and the C-H bending in the aromatic ring of the phenolic resin, respectively [3]. However, the intensities of the latter two peaks were extremely lower than the former peaks.…”
Section: Resultsmentioning
confidence: 77%
“…The macromolecules of the green (un-crosslink) rubber should be crosslink with each other to make a rubber made article for industrial and commercial use. Among of several crosslinking (curing) methods, three methods are widely use, including sulphur (vulcanization), peroxide, and resin (phenolic) crosslinking [3].The final properties of a rubber made article depends to the method of curing directly. As an illustration, for producing a heat and pressure resistance rubber made article, the peroxide and phenolic methods prefer because, in these curing methods, unlike of the sulphur vulcanization with relatively unstable formed C-S and S-S bonds, the stable C-C bonds form between two macromolecules of the rubber [4,5].…”
The cured rubber made bladder is used for curing the green tire because, it is thermally stable, and has low gas permeability. The bladder is made with the cured butyl rubber as a base rubber under a phenolic curing system. To save the resources and also the environmental protection, it should be de-crosslink to gum rubber. Several waste bladder rubber compounds prepared with different de-crosslinking agents in formulation. Subsequently, the prepared compounds irradiated in a microwave oven. The de-crosslinking parameters including the sol fraction and de-crosslinking % measured using traditional rubber swollen tests. It revealed that the Fourier transform infrared spectroscopy (FTIR) graphs were suitable evidences to prove the existence of the phenolic resin in the structure of the used waste bladder butyl rubber powder. Efficient de-crosslinking observed for all studied de-crosslinking agents. It was evidenced by the SEM micrographs and also, the measured crosslink densities of the reclaimed rubbers. The highest and the lowest de-crosslinking %’s belonged to the compounds with DPDS and DCBS in formulation, respectively. Based on the obtained de-crosslinking parameters, the DPDS selected as a suitable de-crosslinking agent for the used waste bladder butyl rubber. In accordance with Horikx analysis, the microwave irradiation broke down the crosslinks and rubber main chains simultaneously. The increasing in microwave irradiation temperature had positive effect on the de-crosslinking process but it had equal effect on crosslink and main chain scission.
“…The Fourier transform infrared spectroscopy (FTIR) graphs used to identify the existence of the phenolic resin in the structure of the waste bladder butyl rubber powder (Figure 3). As observed, the appeared peaks at 3412,1539,1621,1180, and 715 𝑐𝑚 −1 attributed to phenolic hydroxyl (OH), C=C in aromatic ring, the original IR band of the aromatic ring, C-O-C (ether crosslink), and the C-H bending in the aromatic ring of the phenolic resin, respectively [3]. However, the intensities of the latter two peaks were extremely lower than the former peaks.…”
Section: Resultsmentioning
confidence: 77%
“…The macromolecules of the green (un-crosslink) rubber should be crosslink with each other to make a rubber made article for industrial and commercial use. Among of several crosslinking (curing) methods, three methods are widely use, including sulphur (vulcanization), peroxide, and resin (phenolic) crosslinking [3].The final properties of a rubber made article depends to the method of curing directly. As an illustration, for producing a heat and pressure resistance rubber made article, the peroxide and phenolic methods prefer because, in these curing methods, unlike of the sulphur vulcanization with relatively unstable formed C-S and S-S bonds, the stable C-C bonds form between two macromolecules of the rubber [4,5].…”
The cured rubber made bladder is used for curing the green tire because, it is thermally stable, and has low gas permeability. The bladder is made with the cured butyl rubber as a base rubber under a phenolic curing system. To save the resources and also the environmental protection, it should be de-crosslink to gum rubber. Several waste bladder rubber compounds prepared with different de-crosslinking agents in formulation. Subsequently, the prepared compounds irradiated in a microwave oven. The de-crosslinking parameters including the sol fraction and de-crosslinking % measured using traditional rubber swollen tests. It revealed that the Fourier transform infrared spectroscopy (FTIR) graphs were suitable evidences to prove the existence of the phenolic resin in the structure of the used waste bladder butyl rubber powder. Efficient de-crosslinking observed for all studied de-crosslinking agents. It was evidenced by the SEM micrographs and also, the measured crosslink densities of the reclaimed rubbers. The highest and the lowest de-crosslinking %’s belonged to the compounds with DPDS and DCBS in formulation, respectively. Based on the obtained de-crosslinking parameters, the DPDS selected as a suitable de-crosslinking agent for the used waste bladder butyl rubber. In accordance with Horikx analysis, the microwave irradiation broke down the crosslinks and rubber main chains simultaneously. The increasing in microwave irradiation temperature had positive effect on the de-crosslinking process but it had equal effect on crosslink and main chain scission.
“…As shown, the appeared peaks at 3412, 1539, 1621, 1180, and 715 cm−1 demonstrate to phenolic hydroxyl (OH), C = C in aromatic ring, the original IR band of the aromatic ring, C-O-C (ether crosslink), and the C-H bending in the aromatic ring of the phenolic resin, respectively. 4 However, the intensities of the latter two peaks were significantly lower than the former peaks.Figure 3.The FTIR graph for the used waste butyl rubber powder.…”
Section: Resultsmentioning
confidence: 96%
“…3 The final property of a rubber article depends on its curing technique. 4 Typically, cured rubbers with the phenolic and peroxide techniques demonstrate outstanding heat resistance because of the formed stable C-C bonds between the rubber macromolecules after curing.…”
The cured rubber-made bladder used for curing the green tire because, it is thermally stable, and has low gas permeability. The bladder is made with the cured butyl rubber as a base rubber under a phenolic curing system. To save the resources and also, the environmental protection, it should be de-crosslink to gum rubber. A commercial source waste bladder rubber compounded with different de-crosslinking agents, including TMTD, DPDS, DCBS, MBTS, MBT, and TBBS. To do de-crosslinking, the prepared compounds were heated in a laboratory heating oven at different temperatures. The de-crosslinking parameters including the sol fraction and de-crosslinking percent measured using traditional rubber swollen tests. The Fourier transform infrared spectroscopy (FTIR) graphs showed the existence of the phenolic resin in the structure of waste bladder butyl rubber powder. Efficient de-crosslinking was observed for all studied de-crosslinking agents. It evidenced by the scanning electron microscope micrographs and also, the measured crosslink densities of the reclaimed rubbers. The highest and the lowest de-crosslinking percents belonged to the compounds with 4 phr DPDS in recipe at 220 [Formula: see text] and 4 phr DCBS at 180 [Formula: see text], respectively. Based on the obtained de-crosslinking parameters, the DPDS was selected as a suitable de-crosslinking agent for used waste rubber. In accordance with Horikx analysis, the oven heating broke down the crosslinks and rubber main chains simultaneously. Increasing the oven temperature had a positive effect on de-crosslinking process with similar effects on the crosslink and main chain break down.
“…For instance, the direct injection molding of EPDM is performed on the sealing portion of a bipolar plate, and the EPDM-bipolar plate assembly is exposed to high ambient temperatures for the vulcanization of EPDM. The scrap material in this process exhibits misalignment, large thickness deviation, and other process defects resulting from limited process capability during manufacturing, as well as limited recycling ability owing to the irreversible processability of vulcanized elastomer materials [18]. Therefore, if a gasket material exhibits a recycling ability with a consistent sealing property, similar to elastomer gasket materials, it represents a good opportunity for the PEM fuel cell industry to overcome the challenges of process complexities and increased cost.…”
Ethylene–propylene–diene monomer (EPDM) rubber is one of the rapidly developing synthetic rubbers for use as a gasket material in proton exchange membrane (PEM) fuel cell applications. Despite its excellent elastic and sealing properties, EPDM faces challenges such as molding processability and recycling ability. To overcome these challenges, thermoplastic vulcanizate (TPV), which comprises vulcanized EPDM in polypropylene matrix, was investigated as a gasket material for PEM fuel cell applications. TPV showed better long-term stability in terms of tension and compression set behaviors under accelerated aging conditions than EPDM. Additionally, TPV exhibited significantly higher crosslinking density and surface hardness than EPDM, regardless of the test temperature and aging time. TPV and EPDM showed similar leakage rates for the entire range of test inlet pressure values, regardless of the applied temperature. Therefore, we can conclude that TPV exhibits a similar sealing capability with more stable mechanical properties compared with commercialized EPDM gaskets in terms of He leakage performance.
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