Novel branched poly(ɛ-caprolactone) as a nonmigrating plasticizer in flexible PVC: Synthesis and characterization

A series of hyperbranched poly(ɛ-caprolactone) (HPCLs, denoted as D X ) with different molecular weights were synthesized by the copolymerization of GPCL (PCL initiated by glycidol) and succinic anhydride. The chemical structure of D X was characterized by 1 H-NMR gel permeation chromatography and inherent viscosity, and D X was used as the plasticizer for poly(vinyl chloride) (PVC) compared to traditional plasticizer di-(ethylhexyl) phthalate (DEHP). The thermal properties, morphology, mechanical properties, and migration stabilities of PVC films were explored with differential scanning calorimetry, thermogravimetric analysis, scanning electron microscope, tensile, and migration tests. PVC/D 1 exhibited the best plasticization efficiency up to 107%, with enhanced tensile strength (18.5 MPa) and ultimate elongation (416%) compared to PVC/DEHP (11.5 MPa and 375%, respectively). PVC/D 1 exhibited remarkably high plasticization efficiency as compared to PVC/DEHP at a plasticizer concentration of PVC below 40 wt %. Moreover, the migration test for PVC/D X films exhibited minimal plasticizers migration even at very harsh conditions. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135 , 46542.