Replacing Di(2-ethylhexyl) Terephthalate by Di(2-ethylhexyl) 2,5-Furandicarboxylate for PVC Plasticization: Synthesis, Materials Preparation and Characterization

Abstract

The worldwide regulatory demand for the elimination of non-phthalate compounds for poly(vinyl chloride) (PVC) plasticization has intensified the search for alternatives. Concomitantly, sustainability concerns have highlighted sugar-based 2,5-furandicarboxylic acid as one key renewable-chemical for the development of several products, namely di(2-ethylhexyl) 2,5-furandicarboxylate (DEHF) plasticizer. This study addresses the use of DEHF under a realistic scenario of the co-existence of both DEHF and entirely fossil-based plasticizers. More precisely, original PVC blends using mixtures of non-toxic DEHF and di(2-ethylhexyl) terephthalate ester (DEHT) were designed. The detailed structural, thermal, and mechanical characterization of these materials showed that they all have a set of interesting properties that are compatible with those of commercial DEHT, namely a low glass transition (19.2–23.8 °C) and enhanced elongation at break (up to 330%). Importantly, migration tests under different daily situations, such as for example exudation from food/beverages packages and medical blood bags, reveal very low weight loss percentages. For example, in both distilled water and phosphate buffered saline (PBS) solution, weight loss does not exceed ca. 0.3% and 0.2%, respectively. Viability tests show, for the first time, that up to 500 μM of DEHF, a promising cytotoxic profile is observed, as well as for DEHT. Overall, this study demonstrates that the combination of DEHF and DEHT plasticizers result in a noticeable plasticized PVC with an increased green content with promising cytotoxic results.

Recent Attempts in the Design of Efficient PVC Plasticizers with Reduced Migration

“…Still, a study of migration resistance should be carried out to investigate whether the synergistic effect on the migration of two plasticizers occurs. Noteworthy research focused on the introduction of a low molecular weight plasticizer as a secondary plasticizer and was carried out by Matos et al [ 47 ] DEHT was partially (5, 10, 15, 20 phr) replaced by di(ethylhexyl)-2,5-furandicarboxylate (DEHF) in PVC plastics (with whole plasticizer content of 55 phr). When the main plasticizer was replaced by 5 and 10 phr of DEHF, the elongation at break of the PVC sample was significantly elevated; however, a higher content of the secondary plasticizer caused a decrease in elongation.…”

“…One of the first attempts was to search for compounds that have similar structures and physicochemical properties to commonly used plasticizers. In this case, compounds based on furandicarboxylic acid were proposed as novel plasticizers [ 45 , 46 , 47 ]. In 2004, 2,5-furandicarboxylic acid was chosen as one of twelve bio-based building block chemicals by the U.S. Department of Energy, mainly because of its availability to substitute terephthalic acid, i.e., in polyesters.…”

Selective defunctionalization of citric acid to tricarballylic acid as a precursor for the production of high-value plasticizers

“…Besides PTA and a small amount of MSA (7), a small fraction of fragmented products was observed. These consist of acetone (12) and acetic acid (13) and originate from radical fragmentation, which might be facilitated by non-reduced Pd species at the surface of the Pd/C catalyst. 22 Other side products like itaconic acid (4) (or its isomers mesaconic (5) and citraconic acid (6)) and products resulting from the second decarboxylation (8)(9)(10)(11) were not observed in any of the experiments.…”

“…In this respect, epoxidised (and acetylated) vegetable oils 8 and isosorbide diesters 9 have been shown to possess good plasticizing properties for PVC. In addition, effective plasticizers based on cinnamic acid, 4 cardanol 10 and 2,5-furandicarboxylic acid (FDCA) 11,12 have been developed as well. However, the limited availability of cinnamic acid and cardanol, the chemical modifications required for cardanol and the complexities in the synthesis of FDCA from hexoses, somewhat hamper the applicability of these renewable resources for plasticizer production.…”

Endocrine activities of phthalate alternatives; assessing the safety profile of furan dicarboxylic acid esters using a panel of human cell based reporter gene assays

“…FDCA esters are highly relevant biobased alternatives for currently used benzene dicarboxylic acid esters, and can in the case of (ortho) phthalate based plasticisers offer a sustainable alternative. However, in contrast to the ubiquitous phthalate family, thus far no toxicological data were available for 2,5-FDCA esters, although a recent paper mentions that DEHF shows no cytotoxicity in mouse 3T3-L1 cells up to 500 µM for 72 h. 91 In the present study, an in vitro reporter gene assay approach was used to compare the activity profile of commonly used phthalates to that of their furan-based counterparts on a broad series of toxicological endpoints. The assay selection was aimed at the detection of endocrine activity, since several phthalates are heavily scrutinised for their endocrine disrupting properties.…”