Supporting data for Crosslinked polyolefins through tandem ROMP/hydrogenation

Abstract

These files contain primary data along with associated output from instrumentation supporting all results reported in Sample et al. "Crosslinked Polyolefins Through Tandem ROMP/Hydrogenation". Crosslinked polyolefins have important advantages over their thermoplastic analogues, particularly improved impact strength and abrasion resistance, as well as increased chemical and thermal stability; however, most strategies for their production involve post-polymerization crosslinking of polyolefin chains. Here, a tandem ring-opening metathesis polymerization (ROMP)/hydrogenation approach is presented. Cyclooctene (COE)-co-dicyclopentadiene (DCPD) networks are first synthesized using ROMP, after which the dispersed Ru metathesis catalyst is activated for hydrogenation through addition of hydrogen gas. The reaction temperature for hydrogenation must be sufficiently high to allow mobility within the system, as dictated by thermal transitions (i.e., glass and melting transitions) of the polymeric matrix. COE-rich materials exhibit branched-polyethylene-like crystallinity (25% crystallinity) and melting points (Tm = 107 °C), as well as excellent ductility (>750 % extension), while majority DCPD materials are glassy (Tg = 84 °C) and much stiffer (E = 710 MPa); all materials exhibit high tensile toughness. Importantly, hydrogenation of olefins in these crosslinked materials leads to notable improvements in oxidative stability, as saturated networks do not experience the same substantial degradation of mechanical performance as their unsaturated counterparts upon prolonged exposure to air at high temperature.