To suppress the migration of epoxy fat acid methyl ester (EFAME) from plasticized PVC

EFAME

as an internal plasticizer

was covalently bound to poly(vinyl chloride) (PVC) chains via a special synthesis process. The carboxyl-containing PVC (PVC-TSA) was synthesized through nucleophilic substitution reaction between PVC and thiosalicylic acid (TSA)

and then EFAME was added to react with PVC-TSA to gain the internally plasticized PVC (PVC-TSA-EFAME). Fourier transform infrared spectrometry (FTIR) and hydrogen spectrum nuclear magnetic resonance (1H-NMR) confirmed the structures of PVC-TSA and PVC-TSA-EFAME. The 1H-NMR data were further used to calculate the degree of modification. It was found that a degree of modification of 1.2 mol% was achieved using the method of this work. The glass transition temperature (Tg) determination was realized by means of differential scanning calorimetry (DSC). The Tgs of PVC and PVC-TSA-EFAME were respectively 81.4℃ and 37.8℃. Compared to PVC

the marked decrease of Tg was attributed to the introduction of EFAME which increased the flexibility of PVC chains. The extraction and fogging experiments showed that almost no extraction or atomization loss was detected in PVC-TSA-EFAME

which suggested that the migration of EFAME from the plasticized PVC was completely suppressed.