Organobase/urea catalyzed ring opening polymerization of 3‐methyl‐1, 4‐dioxan‐2‐one to prepare chemically recyclable poly(ether ester)

Abstract

AbstractIt is greatly desirable to develop degradable polymers from easily accessible chemicals. In addition to well‐known degradable aliphatic polyesters, poly(ether‐ester) prepared from 1, 4‐dioxan‐2‐one with perfectly alternative ether and ester bonds is a new type of degradable polymer. Due to the low strain of six‐membered 1, 4‐dioxan‐2‐one ring, it remains a challenge to realize the effective and controllable ring‐opening polymerization (ROP) of 1, 4‐dioxan‐2‐one derived monomers despite several catalysts have been attempted. In recent years, the combination of organobase/(thio)urea binary catalytic system has displayed great activity and versatility in the ROP of cyclic esters. Herein, we studied the ROP of 3‐methyl‐1, 4‐dioxan‐2‐one (MDO) using the combinations of various organobases and ureas as catalysts at relatively low temperature. We found that 1, 8‐diazabicyclo[5.4.0]undec‐7‐ene (DBU)/urea pair showed great overall performance in the ROP of MDO, achieving monomer conversion up to 82% within 7 h at −40 °C. Notably, DBU/urea binary catalytic system achieved higher catalytic activity as well as better control over molecular weights and molecular weight distributions compared to previously reported catalysts. The obtained PMDO can completely depolymerize to recover MDO monomer by simple thermolysis, thus established a close‐loop life cycle.