Polyurethanes (PUs), in the form of coatings, adhesives, sealants, elastomers, and foams, play a vital role in the consumer goods, automotive, and construction industries. However, the inevitable disposal of nondegradable postconsumer polyurethane products constitutes a massive waste management problem that has yet to be solved. We address this challenge through the synthesis of biobased and chemically recyclable polyurethanes. Our approach employs renewable and degradable hydroxy telechelic poly(β-methyl-δvalerolactone) as a replacement for petroleum-derived polyols in the synthesis of both thermoplastic polyurethanes and flexible foams. These materials rival petroleum-derived PUs in performance and can also be easily recycled to recover βmethyl-δ-valerolactone monomer in high purity and high yield. This recycling strategy bypasses many of the technical challenges that currently preclude the practical chemical recycling of PUs.

Ap rominent challenge in replacing petrochemical polymers with bioderived alternatives is the efficient transformation of biomass into useful monomers. In this work, we demonstrate ap ractical process for the synthesis of multifunctional alcohols from five-a nd six-carbon acids using heterogeneous catalysts in aqueous media. Design of this process was guided by thermodynamic calculations, which indicate the need for two sequentialh igh-pressure hydrogenations:o ne, reductiono ft he acid to al actone at high temperature;t wo, further reduction of the lactone to the correspondingd iol or triol at low temperature. For example, the conversion of mesaconic acid into (a or b)-methyl-g-butyrolactone was achievedw ith9 5% selectivity at at urnover frequency of 1.2 min À1 over Pd/C at 240 8C. Subsequentc onversion of (a or b)-methyl-g-butyrolactone into 2-methyl-1,4-butanediolw as achieved with ayield of 80 %w ith Ru/C at 100 8C. Thisp rocess is an efficient methodf or the productiono fl actones, diols, andt riols, all valuablem onomersf or the synthesis of bioderived branched polyesters.Scheme1.Hybrid process for the production of bioderived lactones, diols, and branched polymers from glucose.[a] Dr.Supporting Information for this article can be foundu nder http:// dx.

The Cover shows the sequential hydrogenation of five‐carbon acids using Pd and Ru heterogeneous catalysts in aqueous media. In their Communication, C. S. Spanjers et al. demonstrated an efficient process for the synthesis of lactones, diols, and triols from five‐ and six‐carbon acids. The transformation consists of two sequential high‐pressure hydrogenations: reduction of the acid to a lactone at high temperature and further reduction of the lactone to the corresponding diol or triol at low temperature. These products are valuable monomers for the synthesis of bioderived branched polyesters. More information can be found in the Communication by C. S. Spanjers et al. on page 3031 in Issue 19, 2016 (DOI: 10.1002/cctc.201600710).