Migration of phthalate plasticisers in heritage objects made of poly (vinyl chloride): Mechanical and environmental aspects - research data

Materials
Plasticised PVC samples were prepared by solvent casting
method using fine powder of rigid PVC (POLANVIL S, Anwil SA, Poland) and
di-n-butyl phthalate (DBP) plasticiser (>99.5%, Merck KGaA, Germany).
The PVC films of ca. 0.2 mm thickness containing 20 and 30 wt% of DBP
as well as unplasticized PVC film (0% DBP) were cast from tetrahydrofuran
- THF (pure for analysis, Avantor Performance Materials Poland S.A.) and left under
a fume hood to remove residual solvent for at least 2 weeks.

Methods
Dynamic mechanical thermal analysis (DMTA)
DMTA of the PVC films (ca. 0.2 × 8 × 20 mm3) was performed in the tension mode on the Discovery
DMA850 (TA Instruments, USA) in the 10–100 ◦C temperature range
with a heating rate of 1 ◦C/min at 1 Hz frequency under an inert atmosphere.

Molecular Dynamics simulations
The AMBER force field was employed for both the PVC and DBP molecules, while partial atomic
charges were determined using the RESP procedure. The simulations were performed using
the GROMACS software.

Nuclear magnetic resonance (NMR)
NMR experiments were conducted on an Agilent DD2 14 T spectrometer (Santa Clara, California, USA),
equipped with a Doty Scientific DSI-1372 multinuclear probe-head,
which has a maximum magnetic field gradient of 30 T/m. The samples
were placed in the standard 5 mm NMR sample tubes. The bipolar
pulse pair stimulated echo (Dbppste) was employed to
acquire spin echoes. The diffusion time (Δ) was set to 150 ms, the
magnetic field gradient duration (δ) was set to 2 ms, and the magnetic
field gradient (g) was iterated between 0 and 22 T/m in 32 steps.
The experiments were conducted at temperatures ranging from 45 ◦C to 110 ◦C.