We observed from the inverse gated 13 C NMR spectrum (Figure ) that the relative abundance of the L1,4 structural units was high compared to the obtained L1,4 structural units when glycidol was polymerized in an anionic fashion. The excessive presence of L1,4 structural units also indicates that the mechanism of polymerization was through the activated monomer (AM) mechanism, where the glycidol monomers were first activated by carboxylic acid groups before undergoing the ring opening polymerization. We also demonstrated that DTDPA was incorporated in the dendritic polyglycerol core through two-dimensional heteronuclear multiple bond connectivity (HMBC) NMR (Figure ). The correlation between the proton signals of polyglycerol backbone at 3.5 and 4.2 ppm and the ester-carbonyl signal at 180 ppm was an indication for the existence of DTDPA in the polymeric core. To prove that the DTDPA has a major role in the polymerization of glycidol, we performed a control reaction under the same reaction conditions (catalyst free, solvent free and at 70 °C), but without DTDPA. After performing dialysis with a membrane of a molecular weight cutoff (MWCO) of 1 kDa, the reaction yield was negligible (less than 5%). Hence, we could conclude that DTDPA was essential in initiating the reaction.