Barrier properties of chlorobutyl nanoclay composites

Abstract

Elastomeric materials are used as barriers to protect workers against exposure to chemicals. The effectiveness of a polymer as a chemical protective material depends on the rate of permeation of chemicals through it. The permeation rate is dependent on the type and amount of fillers added into the polymer matrix. In this study, Chlorobutyl nanoclay composites were prepared by addition of organically modified and unmodified nanoclays at different filler loadings. The nanocomposites were swollen in three solvents of varying cohesive energy density until equilibrium and desorption experiments were carried out. The data obtained from desorption experiments was used to determine the diffusion coefficients. The concentration-dependent diffusion coeffecient (D) was calculated at high and low concentration regions and it was found that D is one-order less in lower concentration region than in the higher concentration range. The aspect ratio of the nanoclay fillers in the composite was calculated by assuming square and disc shapes and it was found to vary with the type of solvent and the used and filler loading.

Polymer nanotechnology: Nanocomposites

“…Even under the best of circumstances exfoliation of organoclays in neat polyolefins like polypropylene, PP, or polyethylene, PE, is not very good and far less than that observed in polyamides, 200 polyurethanes, and some other polar polymers [84,96,101]. It has been found that a small amount of a polyolefin that has been lightly grafted with maleic anhydride, w1% MA by weight is typical, can act as a very effective ''compatibilizer'' for dispersing the organoclay in the parent polyolefin [84,101,103,106,117,118,[143][144][145][146][147][148].…”

“…The moisture vapor transmission, however, did not show any significant change. Exfoliated clay modified chlorobutyl rubber showed decreased diffusion for several organic chemicals suggesting utility for chemical protective gloves/clothing [200]. Exfoliated clay added to polyamide 6/polyolefin (polyethylene or polypropylene) blends yielded an improved barrier to styrene permeation for melt blown films [201].…”

Recent Developments in the Permeability of Polymer Clay Nanocomposites

“…It has been observed that during the preparation of the nanocomposites, the obtained aspect ratio depends on the volume fraction. In chlorobutyl/montmorillonite nanocomposites, e.g., the obtained aspect ratio decreases with increasing f, using either modified or nonmodified particles [30]. Obviously, increasing f results in a reduction of the degree of delamination and, consequently, in the reduction of the final particle aspect ratio.…”

Transport performance in novel elastomer nanocomposites: Mechanism, design and control

“…Many elastomers have been utilized to attempt to form nanocomposites with high barrier properties, including NR [272,[289][290][291], SBR [292], NBR [281,293], HNBR [278], butadiene rubber (BR) [294], EPDM [281], isobutene-isoprene rubber (IIR) [279,285,295], CR [296], chlorinated isobutene-isoprene rubber [280], FKM [297], and PU [276,298].…”