Omnisec 5

A GPC system from Malvern (Herrenberg, Germany) with a triple detection containing a refractive index detector (VE 3580), a viscometer (270 dual detector) and a multi angle light scattering detector (SEC-MALS 20) was used for GPC analysis. Depending on the molecular weight, different column sets (Malvern, Herrenberg, Germany) were used. For HA-SH samples, two A6000M mixed-bed columns, and for PEG samples, a set of A2000/A3000 columns were chosen. The eluent was prepared using deionized water containing 8.5 g L⁻¹ NaNO₃ and 0.2 g L⁻¹ NaN₃ and the columns were calibrated with PEG standards (Malvern, Herrenberg, Germany). HA-SH samples were dissolved in deionized water with 0.5 g L⁻¹ TCEP over 6 h at rt and PEG samples were dissolved in deionized water over 6 h at rt. The obtained data was processed with OmniSEC 5.12 (Malvern, Herrenberg, Germany).

PNPMA and copolymers were analyzed in DMF (+LiBr, 1 g.L⁻¹) at Laboratory de Chimie des Polymères (LCP), Institut Parisien de Chimie Moléculaire, Sorbonne University. The analyses were performed at a flow rate of 0.8 mL.min⁻¹ and toluene was used as a flow rate marker. All polymers were injected (100 μL) at a concentration of 5 g.L⁻¹ after filtration through a 0.22 μm membrane. The steric exclusion was carried out on two PSS GRAM 1000 Å columns (8 × 300 mm; separation limits: 1 to 1000 kg.mol⁻¹) and one PSS GRAM 30 Å (8 × 300 mm; separation limits: 0.1 to 10 kg.mol⁻¹) with a Tetra detector array (TDA 305) from Malvern Panalytical (Malvern, UK), including a light-scattering detector with a right (90°) and a low (7°) angles (RALS/LALS), a laser at 670 nm, a 4-capillary differential viscometer, a differential refractive index detector (RI) and a diode array UV detector. Columns and detectors were maintained at 60 °C.
The software OmniSEC 5.12 from Malvern Panalytical (Malvern, UK) was used for data acquisition and data analysis. Molar masses (Mn, the number-average molar mass, Mw, the weight-average molar mass) and polydispersity indexes (Ð = Mw/Mn) were calculated with a calibration curve based on narrow poly(methyl methacrylate) (PMMA) standards (from Polymer Standard Services), using only the RI detector.

The molar mass and molar-mass dispersity of the specimens were determined using gel permeation chromatography conducted in chloroform solution at 35 °C with an eluent flow rate of 1 mL/min with a set of two PL-gel 5 μm MIXED-C ultrahigh efficiency columns (Polymer Laboratories, Church Stretton, UK) with a mixed bed and a linear range of M_w = 200–2,000,000 g/mol (for comparison of molar masses before and during the degradation process of specimens printed with various times and speeds of printing) as well as one Mixed E Styragel column with a mixed bed and a linear range up to M_w = 25,000 g/mol (for comparison of molar masses of the specimens after 70 days of degradation). An isocratic pump (Spectra Physics 8800, Newport Corporation, Irvine, CA, USA) as the solvent delivery system and a differential refractive index detector stabilized to a temperature of 35 °C (Shodex SE 61, Showa Denko, Munich, Germany) was applied. 10 μL of 0.5% m/V sample solution was injected into the system. Polystyrene standards (Calibration Kit S-M-10, Polymer Laboratories) with narrow molar-mass dispersity were used to generate a universal calibration curve. The specimens were measured using OmniSEC 5.0 (Viscotek, Malvern, UK) software.