Introducing the reversible chemistry of CO₂with diols mediated by organic superbases into polycarbonate synthesis

Abstract

The reversible reaction of CO2 with alcohols mediated by organic superbases was firstly developed to be a toolbox for capturing CO2 into polymerizable carbonate monomers applicable for thiol–ene click and ADMET polymerization to produce new libraries of polycarbonates.

Eugenol‐derived Organic Liquids as an In‐Situ CO2 Capturing and Conversion System for Eugenol‐based Polycarbonate Synthesis

“…These results demonstrate that all the as‐prepared polycarbonates have good thermostability (Figure 3a, 3c, 3e). It is worth noting that the increase in the length of the aliphatic segment can improve the thermal stability [13,23] . The oxidative post‐polymerization modification of P2a3a results in a decrease in T 5% from 308 °C to 290 °C, and an increase in the char yield from 4.1% to 12.2%, indicating that oxidation can change the thermal stability and thermal degradation behavior of the polymer, which is consisted with previous publications (Figure 3a) [9,23,28] .…”

“…[13,23] The oxidative post-polymerization modification of P2a3a results in a decrease in T 5% from 308 °C to 290 °C, and an increase in the char yield from 4.1% to 12.2%, indicating that oxidation can change the thermal stability and thermal degradation behavior of the polymer, which is consisted with previous publications (Figure 3a). [9,23,28] These results can be explained by the higher thermostability of the sulfone group than those of the thioether group, thus suppressing the decomposition of the polymer chain and small molecular effusion. [31,32] The hydrogenation post-polymerization modification of P2b also increase the thermostability of the polycarbonate, as evidenced by an increase in the T 5% from 290 °C to 341 °C, and the T 50% increased from 378 °C to 385 °C.…”

“…In the 13 C NMR spectrum (Figure 1), new signals of 155.28 ppm, 68.09 ppm and 61.96 ppm appeared after the addition of CO 2 . The signals at 155.28 ppm can be assigned to the carbon on the newly formed mono‐carbonate moiety, and the signals at 68.09 ppm and 61.96 ppm can be assigned to the two methylene carbons, indicating the formation of [TMGH] + [CH 2 CHCH 2 C 6 H 3 (OCH 3 )OCH 2 CH 2 OCO 2 ] − [23] …”

“…The monomers 2a-b were featured by α,ω-diene functional groups, implying that they were applicable for ADMET and thiol-ene click chemistry polymerization, which have been proven to be efficient polymerization methods. [9,23,27,28] To our delight, series of novel polycarbonates were successfully achieved. For example, the metal-free thiol-ene polymerization of 2a with 1,2-ethanedithiol (3a) (Scheme 3) produced a poly(thioether carbonate) P2a3a with a Mw of 29.7 kDa and a polydispersity index (Đe) of 1.6 in 94% yield.…”

Precipitation copolymerization of methyl methacrylate/meth‐acrylate acid in supercritical carbon dioxide

“…In recent years, CO 2 have been widely used as the raw materials or reacting medium to produce the polycarbonates by dispersion or precipitation polymerization. [24][25][26] Although the high molecular weight polymers can be obtained by dispersion polymerization, the stabilizers are required. In general, the synthesis routes of these stabilizers are complex, and it is very difficult to remove completely from materials.…”