Effect of liquid plasticizers on crystallization of PCL in soft PVC/PCL/plasticizer blends

Abstract

In this work, poly(ε‐caprolactone) (PCL) and liquid plasticizer were combined used to plasticize poly(vinyl chloride) (PVC), and the possibility of using PVC/PCL/plasticizer blends to fabricate soft PVC with enhanced migration resistance was investigated. Through partial replacement of liquid plasticizers in soft PVC by equal quantity of PCL, flexibility was maintained while extraction loss of plasticizer by organic solvent was reduced significantly. Furthermore, crystallization of PCL in PVC/PCL/plasticizer blends with low PCL content was observed, and crystallization rate of PCL was found to be influenced by plasticizer contents and structures. For instance, crystallization rate of PCL in PVC/PCL/diisononyl phthalate (DINP) (100/40/100) was 3.7 times faster than in PVC/PCL/DINP (100/40/80), while crystallization rate of PCL in PVC/PCL/dioctyl adipate(DOA)(100/40/100) was 8.3 times faster than in PVC/PCL/diisononyl cyclohexane‐1,2‐dicarboxylate (DINCH) (100/40/100). Low‐field 1H NMR test manifested that different crystallization rate of PCL in PVC/PCL/plasticizer blends with different plasticizer structures was triggered by difference in plasticizers' compatibility with PVC, that is, the number of interaction point between PVC and plasticizers. It is concluded that PCL crystallization favored by liquid plasticizers in PVC/PCL/plasticizer blends was induced by interaction competition between PVC/plasticizer and PVC/PCL. As plasticizer content increases or its compatibility with PVC decreases, interaction competition becomes more intense and consequently faster crystallization of PCL occurs. Thus, to obtain soft PVC products with improve migration resistance while avoiding PCL crystallization, the total content of plasticizer (including both liquid plasticizer and PCL) should be lower than 66 phr (40 wt %). © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020, 137, 48803.

Reorientation of Crystalline Block Copolymer Membranes by Phospholipid Hybridization

“…The DSC results are consistent with DPPC reinforcing PCL intermolecular interactions and crystallinity. Interestingly, even though hydrophobic additives tend to act as plasticizers, − the interactions of the lipid hydrophobic moieties here result in antiplasticization of PCL.…”

“…Additives can promote crystallization − or act as plasticizers such as dinonyl phthalate (DNP) and dioctyl adipate (DOA). − However, in most cases the orientation of the crystal is not controlled. To tune orientation of the self-assembled mesostructures of block copolymers, as well as microcrystallite orientation when polymer blocks crystallize, most methodologies require the use of nanoscale inorganic templates. , Strongly segregated BCPs have also been developed as organic nanotemplates to direct the orientation of block copolymer crystallization .…”

Developments of biobased plasticizers for compostable polymers in the green packaging applications: A review

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Reducing the crystallinity of PCL chains by copolymerization with substituted δ/ε-lactones and its impact on the phase separation of PCL-based block copolymers

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