Polymers of Carbonic Acid. 20. High Molecular Weight Poly(Decamethylene Carbonate) by Ring-Opening Polymerization Initiated with BuSnCl₃or SnOct₂

Highly efficient enzymatic catalysis for cyclocarbonate polymerization

“…Nevertheless, the behavior was different from that of POMC and PDMC (containing 8 and 10 methylene groups per unit), in which the weight loss involves two steps. [38][39][40][41] Another marked disparity is the existence of carbon residue (5-7% weight%) after the thermal decomposition of POMC and PDMC, whereas there was no residue in the case of PTeMC, PHMC [38][39][40][41] and PPMC in this study. It is clear that the thermal decomposition of poly(alkylene carbonate)s may not all follow the same mechanism, and the chemical structure exerts a significant influence on their thermal stability and decomposition mechanism.…”

“…Together with the latent catalyst toxicity, these shortcomings limit the practical application of the Sn(Oct) 2 -catalyzed preparative method. [38][39][40][41] The important role of biosynthetic pathways, such as enzymatic polymerization, has been accepted in the fabrication of biomaterials. Nevertheless, the low catalytic efficiency is known to be the greatest limitation in the industrialization of enzyme catalysis.…”

Anionic polycondensation and equilibrium driven monomer formation of cyclic aliphatic carbonates

“…There are examples in the literature were larger carbonate monomers have been produced under depolymerization conditions, however our system did not result in these cycles (Table 1). 41,44,50,51 This underlines the importance of the catalytic system to produce the desired outcome of the system. Recent report on the DBU and thiourea catalyzed shis in equilibrium conversion points opens the possibility that the thermodynamic equilibrium is not completely independent of the catalytic system employed.…”

“…The inability of this methodology to ringclose larger carbonate rings is in contrast to what has previously been shown where larger cyclic carbonates may undergo ringclosing depolymerization at elevated temperatures. 41,44,50,51 The features of this system is believed to be a consequence of the anionic environment produced via sodium alkoxide. Hence, under these reaction conditions, the diol-length fully controls if the reaction leads to either monomer or polymer formation.…”

“…Nevertheless, reports on using this methodology for the synthesis of propagating cyclic carbonate monomers are comparably scarce, and the reaction conditions employed lacks coherency making general conclusions on the robustness and thermodynamics of RCD difficult. [41][42][43][44][45][46] To shine some light on this methodology we intend to evaluate a wide range of different diols under the same reaction conditions to evaluate what system features that lead either to polycondensation or ring-closing depolymerization. We aim to highlight ring-closing depolymerization as the "go-to" method for cyclic carbonate monomer synthesis in a sustainable, largescale and inexpensive manner.…”