Controllable preparation of poly(alkylene carbonate)s and observation on their structure-related odd–even effect

The primary aim of this paper is to explore the influence of the number of CH2 groups per –(CH2)nOCOO– repeat unit (Numc) on the properties of poly(alkylene carbonate)s. A series of poly(alkylene carbonate)s with different Numc, including PTMC (Numc = 3), PTeMC (Numc = 4), PPMC (Numc = 5), PHMC (Numc = 6) and PDMC (Numc = 10) were investigated for that purpose by DSC and XRD techniques. The method of Sn(Oct)2-catalyzed ring-opening polymerization was developed to prepare poly(pentamethylene carbonate)s (PPMC), which presented a controllable feature. Regarding crystallization rate and Tm of poly(alkylene carbonate)s, an interesting odd–even effect was first reported related to the Numc. The order of crystallizing ability of poly(alkylene carbonate) was: PTMC (Numc = 3) < PPMC(Numc = 5) < PTeMC (Numc = 4) < PHMC (Numc = 6) < PDMC (Numc = 10). Poly(alkylene carbonate)s characterized with even Numc appeared to readily crystallize relative to that with odd Numc.