Highly Effective and Green Catalytic Approach Toward α,ω-Dihydroxy-Telechelic Poly(trimethylenecarbonate)

alpha,omega-Dihydroxy-telechelic poly(trimethylenecarbonate), HO-PTMC-OH, is synthesized from the controlled immortal ring-opening polymerization (ROP) of trimethylene carbonate under mild conditions (bulk, 60 degrees C), using ZnEt2 or, more efficiently, [(BDI)Zn(N(SiMe3)(2))] (BDI= CH(CMeNC6H3-2,6-iPr(2))(2)) as catalyst precursor, in the presence of a diol HO-R-OH (R = (CH2)(2) or CH2C6H4CH2; 0.5-10equiv. vs Zn) acting both as co-initiator and chain transfer agent. Alternatively, HO-PTMC-OH is prepared upon hydrogenolysis of HO-PTMC-OCH2Ph, initially prepared from the ROP of TMC using the [(BDI)Zn(N(SiMe3)(2))]/PhCH2OH system, under smooth operating conditions using Pd/charcoal. Well-defined dihydroxy-functionalized PTMCs of molar mass ranging from (M) over bar (n) = 2 000 to 109 500 g . mol(-1) were thus quantitatively obtained and fully characterized by NMR, MALDI-TOF-MS and SEC analyses. The versatility of this immortal ROP allows the preparation of alike alpha,omega-functional polyester such as linear HO-poly(lactide)-OH, as well as star polymers such as the glycerol-based PTM-OH3.