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