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

Abstract

ABSTRACTA series of hyperbranched poly(ɛ‐caprolactone) (HPCLs, denoted as DX) with different molecular weights were synthesized by the copolymerization of GPCL (PCL initiated by glycidol) and succinic anhydride. The chemical structure of DX was characterized by 1H‐NMR gel permeation chromatography and inherent viscosity, and DX 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/D1 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/D1 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/DX films exhibited minimal plasticizers migration even at very harsh conditions. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46542.