Thiol–ene Click Chemistry Incorporates Hydroxyl Functionality on Polycyclooctene to Tune Properties

Abstract

Polyolefins compose the majority of plastic waste, but conventional mechanical recycling degrades their properties, thereby reducing their value. We report the functionalization of a model for dehydrogenated polyethylene, polycyclooctene (PCOE), with thiol−ene click chemistry to install pendant hydroxyl ethyl thioethers. Functionalization of PCOE using mercaptoethanol via thiol−ene click chemistry yielded functionalization between 1.4 and 22.9% based on ethylene monomeric units. Reactions were well-controlled by varying the reagent stoichiometry and reaction time. Crystallinity and melting temperature decreased, and glass transition temperature increased with greater functionalization. Contact angle measurements reveal an increase in surface polarity with functionalization. Comparisons with poly(ethylene-co-vinyl alcohol) (EVOH) show comparable surface polarity at similar levels of alcohol functionalization. At 12% functionalization, the ultimate shear stress (USS) of functionalized PCOE in an adhesive configuration is 4.10 ± 0.48 MPa, comparable to EVOH. At >12% functionalization, the failure mode changed from adhesive to mixed adhesive−cohesive, and the USS decreased.

Tough polycyclooctene nanoporous membranes from etchable block copolymers

“…Additionally, the backbone alkene could easily be functionalized with hydrophilic moieties through reactions such as thiol-ene click chemistry, an improvement over the relatively inert polyethylene NPMs previously reported. 18,55 Lastly, these membranes could be used as highly selective air filters during times of public health crisis.…”

Copolymers of Vinyl Acetate and Vinyl Carboxylates Bearing Branched C7–C9 Chains: Synthesis, Alcoholysis, and Properties

“…Each specimen was measured seven times at different sites. The crystallinity of the PVVOH/LDPE blends was determined from the melting enthalpy measured by DSC compared to a reference value of 293 J/g for pure LDPE . The sample was first elevated from 25 to 150 °C and kept for 3 min before being cooled down to 0 °C.…”

Multiheaded Cationic Surfactants with Dedicated Functionalities: Design, Synthetic Strategies, Self-Assembly and Performance

“…In general, "click" reactions apply to very selective reagents providing the formation of stable, covalent bonds without any by-products [56][57][58][59]. Two "click" reactions have gained significance in organic synthesis: thiol-ene [60][61][62] and azide-yne ones [57][58][59]. Stable S-C bond generation via the reaction of a thiol group and a double bond comprises a well-known reaction, but it became very common when free-radical conditions were examined for its profound selectivity [63][64][65].…”