This route is considered "greener" compared to the other one, since precursors can be obtained from renewable resources and carbon dioxide.

[1] Ring-opening polymerization (ROP) is the most common method used to synthesize poly(trimethylene carbonate) and their copolymers, since this synthetic route can allow mild reaction condition.

[5] Low molecular weight PTMC is a rubbery polymer with poor dimensional stability, tackiness, and inadequate mechanical properties.

Nevertheless, high molecular weight amorphous PTMC (over 100,000) is very flexible, with a relatively low elastic modulus (5–7 MPa) at room temperature, tough and it presents excellent ultimate mechanical properties.

[4][6] PTMC has resistance to non-enzymatic hydrolysis, compared to most aliphatic polyesters, but it is biodegradable in vivo by enzymes.

So, in vivo, it degrades by surface erosion and its decomposition products contain no organic acids, preventing potential inflammatory responses.

[4] [6] Due to rubbery and hydrophobic nature, PTMC-based copolymers produced from ROP of TMC with lactone-based comonomers have been synthesized to modify these characteristics, amplifying applications.

[8] Poly(glycolide-co-trimethylene carbonate) is a commercial monofilament used for suture with slow biodegradation rate which allows maintenance of high mechanical strength compatible with the surgical recovery.