Quantitative 31 P NMR samples were prepared by dissolving 15-20 mg of product in 500 µL of CDCl3, following a protocol from the literature . Next, 100 µL of a standard cholesterol solution (0.1 mol L -1 in a 1/1.6 CDCl3/pyridine mixture) containing Cr(acac)3, an NMR relaxation agent, was added along with 50 µL of 2 chloro-4,4,5,5-tetramethyl-1,3,2-dioxaphospholane. The number-average molar mass (Mn) of PHO-diol oligomers was obtained from 1 H NMR using Equation . 𝐼 3,6 represents the intensity of the peak at δ = 3.67 ppm, corresponding to the two protons in position α of the primary hydroxyl groups at the end of the chain. The end-of-chain unit with these chemical groups has a molar mass of 89.11 g mol -1 . 𝐼 2,4-2,2 represents the intensity of the peak between δ = 2,4 and 2,2 ppm which is based on the protons in α-position of the secondary OH groups at the end of the chain. The end-of-chain unit possessing these groups has a molar mass of 143.21 g mol -1 . 𝐼 2,6-2,4 represents the intensity of the peaks between δ = 2.6 and 2.4 ppm of the CH 2 in position α of the ester, corresponding to a hydroxy octanoate (HO) repeating unit with a molar mass of 142.20 g mol -1 .