StyragelVR columns (HR6, HR5, HR4, HR3, HR1, and H0.5). The columns were thermostated at 35 °C and tetrahydrofuran (THF), continuously distilled from CaH2, was used as the mobile phase at a flow rate of 1 mL/min. The results were analyzed using the ASTRA 7 software (Wyatt Technology, Santa Barbara, CA, USA). As quality control, a polystyrene standard (Mw 30,000; Mw/Mn = 1.06.) was injected and analyzed using a dn/dc = 0.185 mL/g. Since the dn/dc was unknown for the PBA-DLA_B and S samples, 100% mass recovery was assumed. The software calculated the dn/dc value for each sample. Samples were first dissolved in THF from the distillation to obtain 3-4 mg/mL solutions then 1 mL was filtered into the SEC vials using a 0.45 µm PTFE syringe filter and submitted to the machine. In each case 100 µL was injected.