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The controlled anionic ring-opening polymerization of lactones and siloxanes is carried out in continuous-flow reactors. Anionic ring-opening polymerization of cyclic esters with strong, soluble ba...

The preparation of new ring opening metathesis polymerization (ROMP) monomers using a 1,3-dipolar cycloaddition between aryl azides and norbornadiene is described. Various norbornenetriazolines, obtained through a solvent-and catalyst-free reaction, can subsequently be incorporated into polymer backbones through ROMP reactions. Furthermore, thermal decomposition of the triazoline moiety can allow for further polymer functionalization. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015, 53, 2357–2362

Aliphatic polyesters and polycarbonates are a class of biorenewable, biocompatible, and biodegradable materials. One of the most powerful methods for accessing these materials is the ring-opening polymerization (ROP) of cyclic monomers. Here we report that the deprotonation of ureas generates a class of versatile catalysts that are simultaneously fast and selective for the living ring-opening polymerization of several common monomers, including lactide, δ-valerolactone, ε-caprolactone, a cyclic carbonate, and a cyclic phosphoester. Spanning several orders of magnitude, the reactivities of several diaryl urea anions correlated to the electron-withdrawing substituents on the aryl rings. With the appropriate urea anions, the polymerizations reached high conversions (∼90%) at room temperature within seconds (1-12 s), yielding polymers with narrow molecular weight distributions (Đ = 1.06 to 1.14). These versatile catalysts are simple to prepare, easy to use, and exhibit a range of activities that can be tuned for the optimal performance of a broad range of monomers.

The preparation of terminally functionalized atactic polypropylenes is described. Using standard organic transformations, an olefin terminated polypropylene oligomer could be converted into many other important functional groups. Such species can serve as useful polymer-bound building blocks for synthesis and catalysis. These supported derivatives exhibit high phase-selective solubility in nonpolar solvents, making them excellent candidates for use as supported reagents/catalysts.