Cross-linked networks feature exceptional chemical and mechanical resilience but consequently lack recyclability. Vitrimers have emerged as a class of materials that feature the robustness of thermosets and the recyclability of thermoplastics without compromising network integrity. Most examples of vitrimers have involved new polymers with exchangeable bonds within their backbones. In pursuit of a more universal, commercially viable route, we propose a method utilizing commercially available and inexpensive reagents to prepare vitrimers from vinyl monomer-derived prepolymers that contain cross-linkable βketoester functional groups. Controlled radical copolymerization of methyl methracrylate and (2-acetoacetoxy)ethyl methacrylate afforded linear prepolymers that were converted into vitrimers in a single step by treatment with a trifunctional amine. These materials displayed the characteristic features and reprocessability of vitrimers over as many as six (re)processing cycles. Critically, the networks prepared through this process largely retain the chemical and thermal properties of their linear counterparts, suggesting this method holds significant utility as a user-friendly and commercially relevant approach to the rational design of vitrimers with diverse properties.
Homopolypropylene was modified in the molten state using a new cyclic multifunctional peroxide as the initiator, the Diethyl Ketone Triperoxide (DEKTP), in the presence of different branching/crosslinking co‐agents: Trimethylolpropane Triacrylate (TM), Trimethylolpropane Triacrylate Propoxylate (TMPP), Pentaerythritol Tetraacrylate (PETA) and N′N′‐1,3‐Phenylene Dimaleimida (FDM). Experiments were carried out in an internal mixer at 180 °C, using two different concentrations of co‐agent/initiator; [0.250/0.025] and [0.50/0.05], molar rate = [co‐agent]/[initiator] constant equal to 10. The modified PP′s were evaluated by GPC, FTIR, DSC, WAXD, and MOP. Torque and MFI were also evaluated. The results showed the presence of branches in the backbone of PP when it was modified with TM and PETA.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.