Stanford Advisors


2014-15 Courses


All Publications


  • Urea Anions: Simple, Fast, and Selective Catalysts for Ring-Opening Polymerizations JOURNAL OF THE AMERICAN CHEMICAL SOCIETY Lin, B., Waymouth, R. M. 2017; 139 (4): 1645-1652

    Abstract

    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.

    View details for DOI 10.1021/jacs.6b11864

    View details for Web of Science ID 000393355600048

    View details for PubMedID 28105810

  • Norbornene derivatives from a metal-free, strain-promoted cycloaddition reaction: New building blocks for ring-opening metathesis polymerization reactions JOURNAL OF POLYMER SCIENCE PART A-POLYMER CHEMISTRY Hobbs, C. E., Lin, B., Malinski, T. 2015; 53 (20): 2357-2362

    View details for DOI 10.1002/pola.27691

    View details for Web of Science ID 000360731700007

  • Use of an Isotactic-Propylene/Hexene Copolymer as a New, Versatile, Soluble Support JOURNAL OF POLYMER SCIENCE PART A-POLYMER CHEMISTRY Hicks, A., Lin, B., Osburn, P. L., Hobbs, C. E. 2014; 52 (5): 600-605

    View details for DOI 10.1002/pola.27029

    View details for Web of Science ID 000330108500003

  • Terminal functionalization of atactic polypropylene: a new soluble polymer support TETRAHEDRON LETTERS Lin, B., Lawler, D., McGovern, G. P., Bradley, C. A., Hobbs, C. E. 2013; 54 (8): 970-974