Sorption and diffusion of aldehydes and ketones into natural rubber blends

Siddaramaiah,; Roopa, S.; Premakumar, U.; Varadarajulu, A.

doi:10.1002/(sici)1097-4628(19980103)67:1<101::aid-app12>3.0.co;2-4

Cited by 17 publications

(7 citation statements)

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“…The calculated P values are also tabulated in Table VI. As shown in Table VI, permeability increased with increasing temperature because the molecular relaxation or movement increased with increasing temperature, which in turn, increased the free molecular volume 19, 20. Hence, permeation increased with temperature, and also, the permeability showed systematic relation on the polarity of the probe molecule.…”

Section: Resultsmentioning

confidence: 91%

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An Adamantyl Amino Acid Containing Gramicidin S Analogue with Broad Spectrum Antibacterial Activity and Reduced Hemolytic Activity

Kapoerchan

Knijnenburg

Niamat

et al. 2010

Chemistry A European J

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The cyclic cationic antimicrobial peptide gramicidin S (GS) is an effective topical antibacterial agent that is toxic for human red blood cells (hemolysis). Herein, we present a series of amphiphilic derivatives of GS with either two or four positive charges and characteristics ranging between very polar and very hydrophobic. Screening of this series of peptide derivatives identified a compound that combines effective antibacterial activity with virtually no toxicity within the same concentration range. This peptide acts against both Gram-negative and Gram-positive bacteria, including several MRSA strains, and represents an interesting lead for the development of a broadly applicable antibiotic.

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Section: Resultsmentioning

confidence: 91%

“…In our previous studies, we investigated the transport characteristics of NR blends in n ‐alkanes,18 aldehydes and ketones,19 and aromatic20 hydrocarbon penetrants.…”

Section: Introductionmentioning

confidence: 99%

An Adamantyl Amino Acid Containing Gramicidin S Analogue with Broad Spectrum Antibacterial Activity and Reduced Hemolytic Activity

Kapoerchan

Knijnenburg

Niamat

et al. 2010

Chemistry A European J

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“…[19]: Studies in the sorption, diffusion and permeability of petroleum fuels (kerosene, petrol and diesel) through the vulcanizates were carried out at 30, 40 and 50 °C using the gravimetric method.…”

Section: Methodsmentioning

confidence: 99%

“…The permeability coefficient, P, was calculated from the simple relation [19]: P = DS (8) Energies of absorption. The permeability coefficient, P, was calculated from the simple relation [19]: P = DS (8) Energies of absorption.…”

Section: Methodsmentioning

confidence: 99%

Influence of mixing schemes on ageing, swelling and permeability properties of vulcanizates from blends of natural rubber and low molecular weight natural rubber in petroleum fuels and organic solvents

Malomo¹,

Akinlabi²,

Okieimen³

et al. 2010

CI&CEQ

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Blends of natural rubber (NR) and low molecular weight natural rubber (LMWNR) were compounded using three different mixing schemes by adopting the semi--efficient sulphur vulcanization compounding formulation. In scheme 1, the natural rubber and LMWNR were first mixed before adding the compounding ingredients. In scheme 2, the compounding ingredients were first mixed with the NR before adding the LMWNR and in scheme 3 the compounding ingredients were first mixed with the LMWNR before adding the NR. Properties of the vulcanizates from the three mixing schemes viz-a-viz: chemical resistance, ageing and physico-mechanical properties were investigated and compared. The physico-mechanical results of all the vulcanizates were found to be within the accepted level for NR compounds. The ageing results from all the mixing schemes were found impressing. Vulcanizates from mixing scheme 1 restricted penetration of petroleum fuels and organic solvents best, followed by scheme 2 and the least was scheme 3. The activation energy and free energy change were found to be highest with scheme 1, thereby making mixing scheme 1 being more technologically advantageous than other mixing schemes.

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“…Information about sorption, diffusion and permeability of organic liquids into crosslinked rubber network systems have been studied by some authors. [10][11][12][13] Siddaramaiah et al, 14 found that the rate of solvent transport within a polymer material depended upon the nature of the functional group in the solvents and their interaction with the polymer chain segments. To the best of our knowledge, there is still scanty information on permeability of organic liquids into blends of NR and modified epoxidized low molecular weight natural rubber (ELMWNR).…”

Section: Introductionmentioning

confidence: 99%

Diffusion and permeability of aldehydes into blends of natural rubber and chemically modified low molecular weight natural rubber

Akinlabi

Okieimen

Aigbodion

2005

Polymers for Advanced Techs

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Low molecular weight natural rubber (LMWNR) obtained from natural rubber (NR) by depolymerization of natural rubber latex (NRL) was modified by epoxidation to 35% epoxide level to yield epoxidized low molecular weight natural rubber (ELMWNR). The ELMWNR was in turn modified in a solution of thioglycollic acid (TGA) (0.5 mol phr) to yield a product of 20% conversion of its initial LMWNR epoxide. Blends of NR with LMWNR, ELMWNR and epoxidized low molecular weight natural rubber thioglycollic acid (ELWMNR-TGA) adduct were made. The mixes were vulcanized at 1508C for 20 min before determining the system parameters (n and k), the sorption (S), diffusion (D) and permeability (P) of the vulcanizates in acetaldehyde and formaldehyde solutions at three different temperatures (25, 40 and 608C) for a period of 90 days. The sorption, diffusion and permeability of the vulcanizates were found to be temperature dependent. The vulcanizates containing ELMWNR were found not to be easily penetrated by both acetaldehyde and formaldehyde when compared with base mix A that is vulcanizates with only NR. The reaction system was found not to be spontaneous but dependent on the activation energies. EXPERIMENTALMaterial NRL was obtained from the NIG 805 clone in Rubber Research Institute of Nigeria and preserved with 0.3% ammonia (5% v/v). The latex has a total solid content (TSC) of 41.0% and a dry rubber content (DRC) of 38.5%. The reagents used in the preparation and characterizations of LMWNR, ELMWNR and epoxidized low molecular weight natural rubber thioglycollic acid (ELMWNR-TGA) adduct were of analytical grades while the rubber compounding chemicals were of the commercial grades.

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Sorption and diffusion of aldehydes and ketones into natural rubber blends

Cited by 17 publications

References 0 publications

An Adamantyl Amino Acid Containing Gramicidin S Analogue with Broad Spectrum Antibacterial Activity and Reduced Hemolytic Activity

An Adamantyl Amino Acid Containing Gramicidin S Analogue with Broad Spectrum Antibacterial Activity and Reduced Hemolytic Activity

Influence of mixing schemes on ageing, swelling and permeability properties of vulcanizates from blends of natural rubber and low molecular weight natural rubber in petroleum fuels and organic solvents

Diffusion and permeability of aldehydes into blends of natural rubber and chemically modified low molecular weight natural rubber

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