One‐pot sequence‐selective synthesis of polylactone‐containing block terpolymers based on renewable terpenoid‐derived monomer and a simple organocatalyst

Abstract

In this work, we report the synthesis and polymerization performances of terpenoid-derived camphoric anhydride (CA). Utilizing simple organo-base t BuP 2 as the catalyst, CA can polymerize with various epoxides by efficient and controlled ring-opening alternating copolymerization (ROAC) to afford perfectly alternating poly(CA-alt-epoxide). Kinetic study shows that the polymerization proceeds following zero-order dependence on the concentration of CA. The selfswitchable terpolymerization from the mixture of CA, propylene oxide (PO) and ε-caprolactone (CL) is conducted under the catalysis of t BuP 2 . First, ROAC of CA and PO is carried out exclusively with benzyl alcohol as initiator. Then, block copolymer (BCP) poly(CA-alt-PO)-b-PCL is obtained via the sequential polymerizations after the complete consumption of CA. The followed ringopening polymerization (ROP) of CL is initiated by the terminal hydroxyl of the ROAC-resulted poly(CA-alt-PO) polyester without external stimulus. During the process, the excess PO compound remains intact. The one-pot synthesis displays distinct living nature and perfect chemoselectivity. The as-prepared terpenoidderived alternating and BCP's exhibit elevated thermal properties.

Organocatalytic synthesis of sugar‐derived polyesters via ring‐opening alternating copolymerization of anhydrosugar oxetane and anhydrides

“…7 Camphoric anhydride (CA) was prepared from camphoric acid as previous literature. 39,40 Phthalic anhydride (PA) and succinic anhydride (SA) were purified by recrystallization twice in CHCl 3 and dried under vacuum for 24 h. Other reagents were used without further purification.…”

“…At the chainpropagating stage, the linear fit of the conversion-versustime plots (R 2 = 0.997) indicated zero-order dependence on SA concentration (Figure 1A), which was same as the previously reported epoxide-relative ROCOP. 40,43,47 The molecular mass values grew positively with the conversion values of SA, with the M w /M n values maintaining below 1.25 (Figure 1B). Meanwhile, the GPC traces were unimodal (Figure 1C).…”