Fundamentals of Bis-Maleimide Cure Chemistry

Radical-mediated polymer modifications are robust and inexpensive methods of transforming commodity elastomers and thermoplastics into thermoset articles. Although coagent technologies for improving cross-linking yields are well-established, commercial development has evolved faster than our understanding of underlying chemical principles. This report aims to develop an understanding of a bis-maleimide based coagent system.

 Rheological studies of cis-polybutadiene and LLDPE cure dynamics and yields are augmented with model compound studies to build a mechanistic understanding of these systems. NMR and MS analysis of the products derived from reacting N-phenylmaleimide with cyclooctane indicates that C-H bond addition is the primary means of cross-linking in LLDPE. Similar studies of N-phenylmaleimide reactions with cis-cyclooctene revealed an alternating copolymerization mechanism for polybutadiene + bis-maleimide cures.