Effects of the degree of crosslinking and test rate on the tensile properties of a crosslinked polyacrylic pressure‐sensitive adhesive and vulcanized rubber

Abstract

The effects of the tensile test rate on the properties of a pressure‐sensitive adhesive (PSA) and of vulcanized rubber were ascertained and compared, using a poly(n‐butyl acrylate‐acrylic acid) random copolymer with varying degrees of crosslinking as the PSA. The 100% modulus of the PSA was found to increase along with the crosslinking degree and with faster tensile test rates. In contrast, the 100% modulus of the vulcanized rubber did not exhibit any test rate dependence. To assess this effect, the molecular weights between chemical and physical crosslinking points were determined via equilibrium swelling, dynamic mechanical analysis, and tensile tests. The proportion of physical crosslinking points was found to be far larger in the crosslinked PSA. Because these entanglement points can readily disentangle in response to slow deformation, variations in the test rate only affected the PSA. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47272.

Tack properties and adhesion mechanism of two different crosslinked polyacrylic pressure‐sensitive adhesives

“…However, this is contrary to observations. The previously reported the 100% moduli (the stress at 100% strain) measured by a tensile test at a tensile rate of 5 mm·s −1 at 20°C were 0.37–0.74 MPa for vulcanized IR dependent on the sulfur content and 0.045 MPa for cross‐linked P(BA‐AA) with a crosslinking agent content of 0.050 wt% 13 . The tensile storage modulus ( E ') measured by DMA for vulcanized IR at 20°C was 1.5–2.3 MPa dependent on the sulfur content 13 and the shear storage moduli ( G ') for cross‐linked P(BA‐AA) and cross‐linked P(2EHA‐AA) with a crosslinking agent content of 0.050 wt% at 20°C were 0.26 and 0.18 MPa, respectively (Figure 10(a)).…”

“…In our previous research, 13 the crosslinking density of cross‐linked P(BA‐AA) and vulcanized IR was measured by an equilibrium swelling method using toluene. The molecular weight between crosslinking points was 3.5–35 × 10 4 g·mol −1 for crosslinked P(BA‐AA) and 4.8–15 × 10 3 g·mol −1 for vulcanized IR both dependent on crosslinking agent and sulfur contents.…”

“…Vulcanized IR with various vulcanizing degrees was prepared. The formulation and kneading process have been provided in a previous report 13 …”

“…To confirm the influence of crosslinking, the vulcanized isoprene rubber (IR) with various vulcanizing level was also measured as higher crosslinking density material than PSA. The crosslinking structures of vulcanized IR and cross‐linked P(BA‐AA) were compared in detail previously 13 . Further, the debonding behavior during tack was observed.…”

Cyclometalated Platinum(II) Complexes Simultaneously Catalyze the Cross-Linking of Polysiloxanes and Function as Luminophores

“…The Mooney–Rivlin model was used to interpret mechanical properties (Figure S34). The comparison of the absolute values of M c is not sufficiently accurate as they were calculated by the two different methods. − However, in general, the obtained data are in a good agreement (Section S8, Supporting Infomation).…”