Controlling Polymer Composition in Organocatalyzed Photoredox Radical Ring-Opening Polymerization of Vinylcyclopropanes was written by Chen, Dian-Feng;Boyle, Bret M.;McCarthy, Blaine G.;Lim, Chern-Hooi;Miyake, Garret M.. And the article was included in Journal of the American Chemical Society in 2019.Safety of malonic acid dibutyl ester This article mentions the following:
Although radical polymerizations are among the most prevalent methodologies for the synthesis of polymers with diverse compositions and properties, the intrinsic reactivity and selectivity of radical addition challenge the ability to impart control over the polymerization propagation and produce polymers with defined microstructure. Vinylcyclopropanes (VCPs) can be polymerized through radical ring-opening polymerization to produce polymers possessing linear (l) or cyclic (c) repeat units, providing the opportunity to control polymer structure and modify the polymer properties. Herein, we report the first organocatalyzed photoredox radical ring-opening polymerization of a variety of functionalized VCP monomers, where high monomer conversions and spatial and temporal control were achieved to produce poly(VCPs) with predictable mol. weight and low dispersity. Through manipulating polymerization concentration and temperature, tunable l or c content was realized, allowing further investigation of thermal and viscoelastic materials properties associated with these two distinct compositions Unexpectedly, the photoredox catalysis enables a postpolymn. modification that converts l content into the c content. Combined exptl. and computational studies suggested an intramol. radical cyclization pathway, where cyclopentane and cyclohexane repeat units are likely formed. In the experiment, the researchers used many compounds, for example, malonic acid dibutyl ester (cas: 1190-39-2Safety of malonic acid dibutyl ester).
malonic acid dibutyl ester (cas: 1190-39-2) belongs to esters. Carboxylic acid esters of low molecular weight are colourless, volatile liquids with pleasant odours, slightly soluble in water. Cyclic esters are called lactones, regardless of whether they are derived from an organic or inorganic acid. One example of an organic lactone is γ-valerolactone.Safety of malonic acid dibutyl ester
Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics