title: Completely recyclable biopolymers with linear and cyclic topologies via ring-opening polymerization of γ-butyrolactone.
abstract: Ring-opening polymerization (ROP) is a powerful synthetic methodology for the chemical synthesis of technologically important biodegradable aliphatic polyesters from cyclic esters or lactones. However, the bioderived five-membered γ-butyrolactone (γ-BL) is commonly referred as 'non-polymerizable' because of its low strain energy. The chemical synthesis of poly(γ-butyrolactone) (PγBL) through the ROP process has been realized only under ultrahigh pressure (20,000 atm, 160 °C) and only produces oligomers. Here we report that the ROP of γ-BL can, with a suitable catalyst, proceed smoothly to high conversions (90%) under ambient pressure to produce PγBL materials with a number-average molecular weight up to 30 kg mol(-1) and with controlled linear and/or cyclic topologies. Remarkably, both linear and cyclic PγBLs can be recycled back into the monomer in quantitative yield by simply heating the bulk materials at 220 °C (linear polymer) or 300 °C (cyclic polymer) for one hour, which thereby demonstrates the complete recyclability of PγBL.
authors.affiliation: Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523-1872, USA.
authors.forename: Miao
authors.initials: M
authors.lastname: Hong
authors.affiliation: Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523-1872, USA.
authors.forename: Eugene Y-X
authors.initials: EY
authors.lastname: Chen
mesh_terms: D015107:4-Butyrolactone / Q000737:chemistry*; D063566:Biodegradable Plastics / Q000138:chemical synthesis* / Q000737:chemistry; D001704:Biopolymers / Q000737:chemistry*; D002384:Catalysis; D058105:Polymerization; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013314:Stress, Mechanical; D013499:Surface Properties; D013816:Thermodynamics; D014783:Viscosity
chemical_list: D063566:Biodegradable Plastics; D001704:Biopolymers; D015107:4-Butyrolactone