Organo-catalyzed synthesis of aliphatic polycarbonates in solvent-free conditions

Organocatalytic synthesis of new telechelic polycarbonates and study of their chemical reactivity

“…As described by Naik et al [3], the polymerization reaction occurs according to a two-stage procedure. Firstly, the reaction medium was heated to 100 C during t 1 minutes to allow the in-situ formation of the NHC active species by decarboxylation of BMIM-2-CO 2 .…”

“…Catalyst was synthesized according to the procedure described in literature [3]. 2.90 mL (22 mmol) of 1-n-butylimidazole, 4 mL (47.5 mmol) of dimethyl carbonate (DMC) and 25 mL of methanol were introduced in a Schlenk tube under argon atmosphere.…”

“…DMC is an Eco-friendly product thanks to its biodegradability and low toxicity (1000 times less than phosgene) [2]. Naik et al [3] have obtained polycarbonates by reacting DMC from diols containing 3 to 6 carbons in presence of 1-n-butyl-3-methylimidazolium-2-carboxylate (BMIM-2-CO 2 ) as metal-free pre-catalyst. Decarboxyaltion of BMIM-2-CO 2 induced by heating lead to the formation of an N-heterocyclic carbene (NHC) which is the catalytic active species [3e7].…”

Biodegradable polymers from monomers based on vegetable oils

“…ROP of cyclic ester monomers is one of the most effective methods to obtain homo-or copolyesters with a high molar mass and low dispersity under milder reaction conditions in comparison to condensation polymerization (Scheme 14b) [59,60]. Metallic compounds [61], guanidine based catalysts [62][63][64][65], strong acids [66][67][68], phosphazene [69], N-heterocyclic carbine [70,71], bifunctional thiourea-amine [63,72,73] and enzyme [74][75][76] have been applied as catalysts to the controlled ROP of cyclic esters. Monoglyceride from Nahar seed oil has been used for preparation of polyester resins by reaction with phthalic or maleic anhydride at high temperature.…”

Polycarbonates from biorenewable diols via carbonate metathesis polymerization

“…The unfortunate shortcoming for this process, however, is the low molecular weight of the obtained materials which, therefore, cannot directly be used as biodegradable plastics. 26 Li and coworkers were able to address this shortcoming and produce reasonably higher molecular weight polycarbonates using a novel TiO 2 /SiO 2 -based catalyst. 27 Recently, enzymatic 28 and organocatalytic 29 routes converting dialkyl carbonates and diols to a limited number of polycarbonates have also been demonstrated.…”