ma7b01541_si_001.pdf (305.54 kB)
Effect of Rubber Polarity on Cluster Formation in Rubbers Cross-Linked with Diels–Alder Chemistry
journal contribution
posted on 2017-11-07, 19:51 authored by L. M. Polgar, E. Hagting, P. Raffa, M. Mauri, R. Simonutti, F. Picchioni, M. van DuinDiels–Alder
chemistry has been used for the thermoreversible
cross-linking of furan-functionalized ethylene/propylene (EPM) and
ethylene/vinyl acetate (EVM) rubbers. Both furan-functionalized elastomers
were successfully cross-linked with bismaleimide to yield products
with a similar cross-link density. NMR relaxometry and SAXS measurements
both show that the apolar EPM-g-furan precursor contains
phase-separated polar clusters and that cross-linking with polar bismaleimide
occurs in these clusters. The heterogeneously cross-linked network
of EPM-g-furan contrasts with the homogeneous network
in the polar EVM-g-furan. The heterogeneous character
of the cross-links in EPM-g-furan results in a relatively
high Young’s modulus, whereas the more uniform cross-linking
in EVM-g-furan results in a higher tensile strength
and elongation at break.