PLLA-TAP – FTIR data

PLLA-TAP – FTIR data 1.1.Materials A commercial PLLA grade, Luminy® L-130, with l-isomer content ≥ 99% and melt-flow index of 23 g/10 min (210 °C/2.16 kg), was kindly provided by TotalEnergies Corbion (The Netherlands). Triallyl phosphate (TAP) was purchased from TCI America as GC-grade with purity of 96%. Dicumyl peroxide (P) was purchased from Sigma-Aldrich with a purity of 98%, acetone from Romil as HPLC grade solvent. 1.2. Synthesis of long-chain branched PLLA Operators: Aniello Staiano, Valentina Marturano, IPCB-CNR. Before processing, PLLA pellets were dried overnight under vacuum at 60°C. Preparation of branched PLLA began with a pre-batch, by mixing dicumyl peroxide, triallyl phosphate and dried PLLA pellets in acetone, in order to promote adsorption of the reagents on the pellets surface. After complete evaporation of acetone, the pre-preg polymer pellets were further dried in at 60 °C under vacuum to remove traces of residual acetone, and of humidity. Reactive mixing was carried out using a Brabender Plastograph EC (Brabender GmBH & Co.KG, Germany), at 180°C and mixing rate of 100 rpm for 6 minutes. Plain PLLA pellets were also processed using the same protocol. Seven formulations were prepared, by fixing peroxide content at 0.2 wt%, while varying TAP from 0.1 to 1 wt%, as detailed in Table 1, which also presents sample codes. Table 1. Sample codes and compositions Sample code PLLA (g) P (g) TAP (g) PLLA 100 0 0 TAP01 100 0.2 0.1 TAP02 100 0.2 0.2 TAP04 100 0.2 0.4 TAP06 100 0.2 0.6 TAP08 100 0.2 0.8 TAP1 100 0.2 1 1.3.Attenuated total reflectance Fourier transform infrared (FTIR) spectroscopy Operator: Huidi Sun, KTH. Fourier transform infrared spectroscopy was performed with a PerkinElmer 100 spectrometer equipped with an attenuated total reflection (ATR) setup. All spectra were recorded in the range of 600-4000 cm−1, using 16 scans at a resolution of 8 cm−1. The data report FTIR (ATR) spectra of PLLA and PLLA-TAP, normalized to the carbonyl stretching band at 1748 cm-1.