Crosslinking of an ethylene-glycidyl methacrylate copolymer with amine click chemistry

• Published in: Polymer (Guilford) Vol. 111; pp. 27 - 35
• Main Authors: Mauri, Massimiliano, Tran, Nina, Prieto, Oscar, Hjertberg, Thomas, Müller, Christian
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 24.02.2017; Elsevier BV
• Subjects: Amine; Byproducts; Chemical synthesis; Chemistry; Copolymers; Crosslinking; Crosslinking polymerization; Curing; Curing agents; Epoxy; Extrusion; Functional groups; Glycidyl methacrylate; Polyethylene; Polyethylene copolymer; Polyethylenes; Crosslinking; Glycidyl methacrylate; Amine; Epoxy; Polyethylene copolymer
• ISSN: 0032-3861; 1873-2291
• DOI: 10.1016/j.polymer.2017.01.010

Commonly used crosslinking methods for polyethylenes result in the release of harmful by-products. Here, we demonstrate that an epoxy-bearing polyethylene copolymer, which contains 8 wt% glycidyl methacrylate, can be efficiently crosslinked without by-product formation. Click chemistry based on multifunctional amine curing agents, which carry at least two functional groups separated by a flexible spacer, was used to prepare thermosets. Compounding of the crosslinker and copolymer through extrusion at 120 °C could be carried out without onset of the curing reactions. Careful adjustment of the curing time and temperature, ranging from 20 to 120 min and 160–200 °C, resulted in a high network density of at least 2.8 crosslinks per 1000 carbons at a curing agent stoichiometry of as little as 0.5 wt%. Efficient crosslinking of a branched statistical ethylene-glycidyl methacrylate copolymer with bifunctional amine crosslinking agents is demonstrated. The use of click chemistry opens up a by-product free alternative to traditional crosslinking with peroxides. A well-adjusted processing window around 120 °C permits extrusion of the copolymer and curing agent, followed by crosslinking at 160–200 °C. [Display omitted] •The use of click chemistry opens up a by-product free alternative to traditional crosslinking of polyethylene with peroxides.•A statistical ethylene-glycidyl methacrylate copolymer can be crosslinked with bifunctional amine crosslinking agents.•Processing at 120 °C permits extrusion of the copolymer and amine curing agent, followed by crosslinking at 160–200 °C.