Tackiness of GR-S and Other Elastomers

Abstract

The analysis of tackiness shows that it is a complex property which depends on a balance between a large number of different factors, including the geometry of the sample as well as the surface forces and the visco-elastic properties of the material itself. The quantitative measurements of the effect of the rate of removal on the apparent tackiness of pressure-sensitive adhesive tapes show that significant differences are found at very slow removal rates (105 seconds per cm.) which do not show up at much higher removal rates (10 seconds per cm.). These differences may affect the performance of the tapes in service. A simple quantitative test is described which can be used to study the effects of various processing treatments and various softeners, tackifiers and other compounding ingredients on the tackiness of GR-S and other rubbers. Koresin was the most effective tackifier found for GR-S. The authors wish to acknowledge the continued interest of W. E. Hanford, Director of the Laboratory, and the helpful discussions of tackiness measurements with C. E. Schildknecht. Miss Ruth Sellers and Miss J. L. Nuver helped in taking much of the data. The first Koresin samples were prepared in the laboratory by C. E. Schildknecht and A. O. Zoss before the commercial material was available.

Autohesion Behavior of Brominated-Isobutylene-Isoprene Gum Nanocomposites with Layered Clay

“…Meanwhile, other literatures have also reported that addition of carbon black to SBR and EPDM lowers the tack strength as compared to that of the gum elastomers. 4,10,11,25,26 On the contrary, adding nanoclay content above 8 phr, sufficiently improved the green strength of the specimen without the material losing its original interdiffusion or contact flow properties fully. According to Kumar et al, 8 it is well-known that the addition of reinforcing fillers will increase the green strength of synthetic elastomers and can reduce the contact flow and extent of diffusing rubber molecules at the tack junction.…”

“…6,8 It has also been reported that the addition of reinforcing fillers like carbon black can influence the tack strength of elastomers. [9][10][11][12][13] For instance, addition of 40 phr of carbon black to natural rubber (NR) resulted in a significant increase in the tack strength of NR. 9 The increase in the tack strength has been attributed to an increase in cohesive strength due to filler reinforcement.…”

“…4 Moreover, it has already been established that a typical SBR cannot readily achieve bond formation due to the unfavorable intrinsic characters of the elastomer such as molecular weight and viscosity. 10 The addition of filler further restricts the chain mobility, reducing the interfacial interactions leading to lower tack. 10 Therefore, it was concluded that the effect of carbon black addition on tackification depends more on elastomers' ability to achieve bond formation, rather than its specific chemical nature.…”

“…10 The addition of filler further restricts the chain mobility, reducing the interfacial interactions leading to lower tack. 10 Therefore, it was concluded that the effect of carbon black addition on tackification depends more on elastomers' ability to achieve bond formation, rather than its specific chemical nature. 4,11 Nanoclays have been used as a potential reinforcing agent for various elastomers over the past decade.…”