Synthesis and thermal characterization of poly(dimethyl bicyclobutane-1,3-dicarboxylate) and its copolymers

Bicyclobutanes and cyclobutenes: Unusual carbocyclic monomers

“…3‐Cyanocyclobutanone proved to be a fertile source of novel polymerizable bicyclobutanes 4–7. We established that, although the parent hydrocarbon did not polymerize satisfactorily, bicyclobutanes carrying electron‐attracting groups at the 1‐ or 1,3‐positions polymerized very well.…”

“…Choi et al7 improved the synthesis of the 1,3‐bicyclobutane diester, again starting from 3‐cyanocyclobutanone. Free‐radical homopolymerizations and copolymerizations were performed successfully to form a polymer with remarkable properties (discussed later).…”

“…Comparable results were obtained for the 1,2‐enchained polymers from the cyclobutene monomers. However, the free‐radical polymerization of dimethyl bicyclobutane‐1,3‐dicarboxylate gave a highly stereoregular polymer with approximately 95% trans enchainment 7…”

“…The polymers obtained from dimethyl bicyclobutane‐1,3‐dicarboxylate were subjected to thermal analysis 7. They showed a T g value of 159 °C, which is much higher than that of poly(methyl methacrylate) (PMMA; 95 °C).…”

Catheter closure of accessory pulmonary blood flow after bidirectional Glenn anastomosis using Amplatzer duct occluder

“…For example, bicyclobutane polymers do not undergo thermal depolymerization as does poly(methyl methacrylate) (PMMA). Accordingly, the cyclobutane unit might act as a “zipper‐jamming” unit to suppress depolymerization in vinyl copolymers, such as with PMMA 16. These enhanced properties may qualify them for specialty, high‐tech applications.…”