Organocatalyzed Synthesis and Degradation of Functionalized Poly(4-allyloxymethyl-β-propiolactone)s

Abstract

The chemical synthesis of degradable poly(β-hydroxyalkanoate) (PHA) produced by microorganisms allows the control of the solubility, crystallinity, hydrophobicity, degradability, thermal, and mechanical properties by introducing functionality on the side chain. Herein, we synthesized a PHA derivative containing a pendant allyl group via the anionic ring-opening polymerization of a 4-allyloxymethyl-β-propiolactone (AMPL) monomer, which was prepared via the carbonylation of allyl glycidyl ether. The AMPL monomer was subjected to various organocatalysts in bulk to yield poly(4-allyloxymethyl-β-propiolactone) (PAMPL) with controllable molecular weight and dispersity. The prepared PAMPL polymers were characterized via 1 H and 13 C NMR, gel permeation chromatography (GPC), differential scanning calorimetry (DSC), and matrix-assisted laser desorption/ ionization-time-of-flight (MALDI-TOF) analyses. A photoactivated thiol−ene reaction allowed the postpolymerization modification of PAMPLs with varying substituents. Functionalized PAMPL polymers degraded under chemical and thermal conditions, and importantly, cross-linked PAMPL films degraded during exposure to soil and seawater under a wide range of degradation kinetics. This study provides the future potentials of the chemically synthesized and functionalized PHA for replacing conventional petroleum-derived polymers.

Poly(hydroxyalkanoates): Production, Applications and End-of-Life Strategies–Life Cycle Assessment Nexus

“…PHAs can also be produced via chemical synthesis from lactones through ring-opening polymerization (ROP) in which better control of properties of resultant polymers is achievable. This approach utilizes initiators, monomers such as β-lactones and cyclic esters, and metal catalysts for polymerization to occur . Diverse homopolymers and copolymers may be produced using a clever combination of monomers and catalysts. , A recent study reported the possibility of using nonmetallic catalysts in ring-opening polymerization of β-butyrolactone (BBL).…”

“…In another study, Yu et al recently reported PHA polymerized from 4-allyloxymethyl-β-propiolactone monomer (AMPL) through anionic-ROP using organocatalysts. The resultant poly­(AMPL) was modified through photoactivation and achieved excellent degradation profiles in soil and seawater mediums . Makaguchi and colleagues used diphenyl phosphate (DPP) as a catalyst and 3-phenyl-1-propanol as an initiator in toluene to perform ROP of δ-valerolactone (δ-VL) and ε-caprolactone (ε-CL) at room temperature.…”

Post-polymerisation modification of poly(3-hydroxybutyrate) (PHB) using thiol–ene and phosphine addition

“…26 Yu and co-workers investigated the post-polymerisation modification of both allylic side chains and crotonic end groups of poly(4-allyloxymethyl-β-propiolactone). 27…”

“…26 Yu and co-workers investigated the post-polymerisation modification of both allylic side chains and crotonic end groups of poly(4-allyloxymethyl-β-propiolactone). 27 Further, phosphines can be regarded as potentially interesting reaction partners for crotonates as they participate in Michael-addition reactions and are commonly used as catalysts. 28,29 Galkin and co-workers reported on the functionalisation of unsaturated carboxylic acids using phosphines.…”

Anionic Polymerization of Polar Conjugated Diene Monomers with Phosphine as the Initiator and Subsequent Ring Closure without Highly Dilute Conditions

“…Of course, various macromolecular designs using organic catalysts have enabled researchers to synthesize many kinds of vinyl polymers. Anionic polymerizations, conventional alkyllithiums, and Grignard reagents , are well-known as the most accessible candidates for this purpose, and many controlled polymerizations of vinyl monomers have already been reported. − Moreover, along with the recent progress in advanced radical and cationic polymerizations, − anionic polymerizations have also advanced. These progressions would not have been possible without Lewis pair polymerization (LPP) .…”