Degradable Polymer Structures from Carbon Dioxide and Butadiene

The utilization of carbon dioxide as a polymer feedstock is an ongoing challenge. This report describes the catalytic conversion of carbon dioxide and an olefin comonomer, 1,3-butadiene, into a polymer structure that arises from divergent propagation mechanisms. Disubstituted unsaturated delta-valerolactone 1 (EVL) was homopolymerized by the bifunctional organocatalyst 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD) to produce a hydrolytically degradable polymer. Isolation and characterization of reaction intermediates using H-1, C-13, COSY, HSQC, and MS techniques revealed a vinylogous 1,4-conjugate addition dimer forms in addition to polymeric materials. Polymer number-average molecular weights up to 3760 g/mol and glass transition temperatures in the range of 25-52 degrees C were measured by GPC and DSC, respectively. The polymer microstructure was characterized by H-1, C-13, FTIR, MALDI-TOF MS, and ESI tandem MS/MS. The olefin/CO2-derived materials depolymerized by hydrolysis at 80 degrees C in 1 M NaOH. This method and the observed chemical structures expand the materials and properties that can be obtained from carbon dioxide and olefin feedstocks.

Automated summary

This study explores the catalytic conversion of carbon dioxide and an olefin comonomer, 1,3-butadiene, into a hydrolytically degradable polymer, expanding the range of materials and properties that can be obtained from carbon dioxide and olefin feedstocks.