Natural zeolite particles of 40, 80 and I00 phr were incorporated into natural rubber （NR） using a two-roll mill. The surface treatment of zeolite particles was expected to improve their cure characteristics and the...Natural zeolite particles of 40, 80 and I00 phr were incorporated into natural rubber （NR） using a two-roll mill. The surface treatment of zeolite particles was expected to improve their cure characteristics and their tensile properties. Two types of silane coupling agents, i.e., bis-[3-（triethoxysilyl）-propyl]-tetrasulfide （Coupling 89） and 3-Octanoylthio-l-propyltriethoxysilane （NXT） at various loadings of 2, 4 and 8 percent by weight （%wt） were selected. The viscosity and cure time of the rubber compound increased, while the scorch time decreased after the treatment of zeolite by both coupling agents. The viscosity of the rubber compound predominantly increased when increasing Coupling 89, however, NXT loadings showed no significant effect on the cure characteristics Moreover, the amount and type of coupling agent influenced the tensile properties of the vulcanizates, as a result of the increase in tensile strength, and tensile modulus with increasing both coupling agents loading. The tensile properties of the vulcanizates increased at low Coupling 89 concentrations （2-4%wt）, but decreased at high Coupling 89 loading （8%wt）. Since NXT has a less bulky structure and lower viscosity compared with Coupling 89, it thus reacts with the silanol groups on the zeolite surface more readily, resulting in the decrease in filler-filler interaction, leading to better tensile properties.展开更多
In this work,we show for the first time that high-silica zeolites(MFI,TON,MTT,and*MRE)could be synthesized from a combined strategy of both zeolite seeding and alcohol filling in the absence of organic structure-direc...In this work,we show for the first time that high-silica zeolites(MFI,TON,MTT,and*MRE)could be synthesized from a combined strategy of both zeolite seeding and alcohol filling in the absence of organic structure-directing agents(OSDAs).High-silica ZSM-5 zeolites with Si/Al ratios ranging from 38 to 240(TF-Al-ZSM-5)could be synthesized via this route.The key to the success of this technique was the employment of an aluminosilicate precursor with a fully 4-coordinated aluminum species as the initial source,wherein the rearrangement and condensation of the silicate species,rather than the aluminate species,occurred during zeolite crystallization.In addition,heteroatoms,such as Fe and B,could be incorporated into the zeolite frameworks.Catalytic tests for the methanol-to-propylene(MTP)reaction exhibited good catalytic performance for TF-Al-ZSM-5,which was comparable to that of the aluminosilicate ZSM-5 zeolite synthesized with OSDAs.Hence,this method offers viable opportunities for the industrial production and catalytic application of high-silica zeolites in the future.展开更多
Hydrophobic ZSM-5 zeolite filled polydimethylsiloxane （PDMS） composite membranes with Nylon micro-filtration membrane as the support layer were prepared to separate acetaldehyde from its aqueous solution. The compos...Hydrophobic ZSM-5 zeolite filled polydimethylsiloxane （PDMS） composite membranes with Nylon micro-filtration membrane as the support layer were prepared to separate acetaldehyde from its aqueous solution. The composite membranes were characterized by Fourier transform infrared spectroscopy and X-ray diffraction. Their structural morphology and thermal stability were also examined. The swelling study showed that the composite membranes presented higher degree of swelling in aqueous solution of acetaldehyde than in pure water at 25℃,展开更多
The mechanical properties, thermal and gasohol resistance of the natural zeolite, rice husk ash （RHA） and perlite-filled natural rubber （NR） with addition of carbon black （CB） loading was studied. The amount of ...The mechanical properties, thermal and gasohol resistance of the natural zeolite, rice husk ash （RHA） and perlite-filled natural rubber （NR） with addition of carbon black （CB） loading was studied. The amount of fillers （natural zeolite, RHA and perlite） filled in the vulcanizates has been fixed at 20 phr, while CB loading was varied in a range of 0-45 phr. It was found that the tensile strength, percentage of elongation at break, modulus and hardness of the vulcanizates filled with all kinds of fillers increased with the increase of CB loading, while there was no significant change in the compression set. Moreover, at this particular filler loading （20 phr）, the addition of perlite has significant effect on gasohol resistance of the vulcanizates in which gasohol resistance （various ethanol ratio） of the vulcanizates was significantly improved with perlite loading compared with others.展开更多
文摘Natural zeolite particles of 40, 80 and I00 phr were incorporated into natural rubber （NR） using a two-roll mill. The surface treatment of zeolite particles was expected to improve their cure characteristics and their tensile properties. Two types of silane coupling agents, i.e., bis-[3-（triethoxysilyl）-propyl]-tetrasulfide （Coupling 89） and 3-Octanoylthio-l-propyltriethoxysilane （NXT） at various loadings of 2, 4 and 8 percent by weight （%wt） were selected. The viscosity and cure time of the rubber compound increased, while the scorch time decreased after the treatment of zeolite by both coupling agents. The viscosity of the rubber compound predominantly increased when increasing Coupling 89, however, NXT loadings showed no significant effect on the cure characteristics Moreover, the amount and type of coupling agent influenced the tensile properties of the vulcanizates, as a result of the increase in tensile strength, and tensile modulus with increasing both coupling agents loading. The tensile properties of the vulcanizates increased at low Coupling 89 concentrations （2-4%wt）, but decreased at high Coupling 89 loading （8%wt）. Since NXT has a less bulky structure and lower viscosity compared with Coupling 89, it thus reacts with the silanol groups on the zeolite surface more readily, resulting in the decrease in filler-filler interaction, leading to better tensile properties.
文摘In this work,we show for the first time that high-silica zeolites(MFI,TON,MTT,and*MRE)could be synthesized from a combined strategy of both zeolite seeding and alcohol filling in the absence of organic structure-directing agents(OSDAs).High-silica ZSM-5 zeolites with Si/Al ratios ranging from 38 to 240(TF-Al-ZSM-5)could be synthesized via this route.The key to the success of this technique was the employment of an aluminosilicate precursor with a fully 4-coordinated aluminum species as the initial source,wherein the rearrangement and condensation of the silicate species,rather than the aluminate species,occurred during zeolite crystallization.In addition,heteroatoms,such as Fe and B,could be incorporated into the zeolite frameworks.Catalytic tests for the methanol-to-propylene(MTP)reaction exhibited good catalytic performance for TF-Al-ZSM-5,which was comparable to that of the aluminosilicate ZSM-5 zeolite synthesized with OSDAs.Hence,this method offers viable opportunities for the industrial production and catalytic application of high-silica zeolites in the future.
基金Supported by Shanghai Natural Science Foundation (10ZR1432000)Kwang-Hua Fund for College of Civil Engineering,Tongji University
文摘Hydrophobic ZSM-5 zeolite filled polydimethylsiloxane （PDMS） composite membranes with Nylon micro-filtration membrane as the support layer were prepared to separate acetaldehyde from its aqueous solution. The composite membranes were characterized by Fourier transform infrared spectroscopy and X-ray diffraction. Their structural morphology and thermal stability were also examined. The swelling study showed that the composite membranes presented higher degree of swelling in aqueous solution of acetaldehyde than in pure water at 25℃,
文摘The mechanical properties, thermal and gasohol resistance of the natural zeolite, rice husk ash （RHA） and perlite-filled natural rubber （NR） with addition of carbon black （CB） loading was studied. The amount of fillers （natural zeolite, RHA and perlite） filled in the vulcanizates has been fixed at 20 phr, while CB loading was varied in a range of 0-45 phr. It was found that the tensile strength, percentage of elongation at break, modulus and hardness of the vulcanizates filled with all kinds of fillers increased with the increase of CB loading, while there was no significant change in the compression set. Moreover, at this particular filler loading （20 phr）, the addition of perlite has significant effect on gasohol resistance of the vulcanizates in which gasohol resistance （various ethanol ratio） of the vulcanizates was significantly improved with perlite loading compared with others.
