Gelation/fusion behavior of PVC plastisol with a cyclodextrin derivative and an anti-migration plasticizer in flexible PVC

• Published in: European polymer journal Vol. 48; no. 5; pp. 885 - 895
• Main Authors: Yu, Byong Yong, Lee, Ah Reum, Kwak, Seung-Yeop
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01.05.2012; Elsevier
• Subjects: Applied sciences; Blends; Cyclodextrin derivative; Exact sciences and technology; Forms of application and semi-finished materials; Gelation and fusion process; Migration inhibitor; Plasticizer; Polymer industry, paints, wood; PVC plastisol; Technology of polymers; Cyclodextrin derivative; Migration inhibitor; Plasticizer; Gelation and fusion process; PVC plastisol; Viscoelasticity; Phthalic acid esters; Plastisol; Transport properties; Migration; Mechanical properties; Experimental study; Foil; Glass transition temperature; Diester; Polyvinyl chloride
• ISSN: 0014-3057; 1873-1945
• DOI: 10.1016/j.eurpolymj.2012.02.008

Viscoelastic profile of PVC/DINP-CD and PVC/Neo-CD plastisol as a function of temperature (left) and formation of molecular entanglement; PVC containing Bz-β-CD (right). [Display omitted] ► PVC plastisols with cyclodextrin derivative were prepared. ► Cyclodextrin derivative was expected to facilitate formation of complexes with plasticizers. ► The curing conditions of PVC plastisol were optimized by rheological analysis. ► Cyclodextrin derivative played a key role in inhibiting plasticizer migration. We successfully evaluated the effects of 2,3,6-per-O-benzoyl-β-cyclodextrin (Bz-β-CD) on the rheological properties of PVC plastisols and the migration behavior of plasticizer from flexible PVC. Two types of plasticizer, di-isononyl phthalate (DINP) and diisononyl cyclohex-4-ene-1,2-dicarboxylate (Neocizer), along with Bz-β-CD as a migration inhibitor were mechanically mixed into an emulsion grade PVC resin to prepare plastisols. The presence of Bz-β-CD was expected to facilitate formation of stable complexes with DINP or Neocizer in the flexible PVC. It was necessary to determine whether changes in the processing conditions of the PVC plastisol were needed for use in this application. To this end, the viscoelastic properties of the plastisols, including the elastic modulus, G′, and the viscous modulus, G″, were continuously monitored as a function of temperature during the gelation and fusion processes using rheological analysis techniques. The results showed that complete gelation was slightly delayed and both moduli (G′ and G″) decreased upon addition of Bz-β-CD to the PVC matrix. FE-SEM images yielded insight into the gelation and fusion processes. The curing conditions and physical properties of the flexible PVCs containing Bz-β-CD were optimized, and the influence of Bz-β-CD on the migration of the plasticizers and the stability of the flexible PVC was studied. The results showed that Bz-β-CD reduced migration of DINP and Neocizer from the flexible PVC by almost 40% and 25%, respectively, thereby favorably restricting migration within the flexible PVC.