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. 2020 May 4;11(25):6567–6581. doi: 10.1039/d0sc00463d

Overview of triblock polyesters (TBPEs) characterization dataa.

Sample M n,NMR b (kg mol−1) M n,SEC c (kg mol−1) [Đ] f hard d DPPE–DPPDL–DPPEe N tot f T g1, Tg2g (°C) OTWi (°C)
TBPE-1 8–27–8 45.0 [1.05] 0.40 35–164–35 653 −49, 105 173
TBPE-2 13–34–13 61.3 [1.10] 0.44 52–209–52 890 −50, 122 192
TBPE-3 14–45–14 75.0 [1.07] 0.41 59–269–59 1088 −50, 123 193
TBPE-4 17–46–17 85.3 [1.06] 0.44 73–291–73 1238 −50, 126 195
TBPE-5 20–65–20 102 [1.09] 0.40 79–371–79 1480 −51, 138 206
TBPE-6 13–69–13 106 [1.06] 0.29 58–455–58 1538 −42, 146h 188
TBPE-7 10–68–10 89.8 [1.05] 0.24 42–406–42 1303 −41, 136h 177
TBPE-8 10–93–10 105 [1.07] 0.19 38–506–38 1524 −44, 132h 176
TBPE-9 5–91–5 108 [1.08] 0.12 24–565–24 1567 −44, 123h 167
a

Reaction conditions: = 1.7 M in toluene, catalyst = [LZnMg(C6F5)2] (see ESI for structure), chain transfer agent = 1,4-BDM, T = 80 °C, see Table S1 for more reaction data.

b

Estimated from the 1H NMR spectra of the purified polymer by integration of the aromatic 1,4-BDM resonance (7.34 ppm) against those of PE (7.58 ppm) and PDL (4.85 ppm).

c

Estimated by SEC with THF eluent, RI and UV detector, calibrated using PS standards.

d

Volume fraction of hard block determined from the wt% hard block using eqn (S1) and previously reported room temperature densities for PE = 1.04 g cm−3 and PDL = 0.97 g cm−3.21,54 The wt% hard was calculated from the 1H NMR spectra of the purified polymers by comparison of the relative integrals (±3% error) of an aromatic resonance in PE (7.58 ppm) and the –CH resonance in PDL (4.85 ppm).

e

Degree of polymerization for PE–PDL–PE blocks calculated from Mn,SEC of the overall triblock, the wt% hard block from 1H NMR spectroscopy and the mass of repeat unit for PE (246.3 g mol−1) and PDL (170.3 g mol−1).

f

Total degree of polymerization (eqn (S2)) calculated from the sum of Mn of the component blocks and using a reference segment volume of 0.118 nm3.

g

Estimated by DSC (10 °C min−1 heating rate), second heating curve.

h

Determined from the maximum in the peak of tan(δ) by DMTA (1 Hz, 5 °C min−1 heating rate).

i

Operating temperature window (OTW) calculated as the difference between upper and lower Tg values.