Application of a bio‐based polyester plasticizer modified by hydrosilicon‐hydrogenation reaction in soft PVC films

Abstract

A kind of bio‐based plasticizer, poly (hexanediol maleic) (MH), was synthesized using 1,6‐hexalene and maleic acid as raw materials, and it was modified by hydrosilicon‐hydrogenation reaction to improve its plasticizing efficiency. The chemical structure and plasticizing performance of MH and its modification product (MHA) were characterized by Fourier‐transform infrared spectroscopy (FTIR), proton nuclear magnetic resonance (1H‐NMR), X‐ray photoelectron spectroscopy (XPS), and Dynamic mechanical analysis (DMA). It was found that the hydrosilicon‐hydrogenation modification effectively improved the plasticizing efficiency of MH, reflecting on the decreased Tg and the increased elongation at break of PVC blends. The migration resistance of PVC blends was tested and analyzed by solubility parameters, which revealed that the migration stabilities of PVC blends were promoted after modification. It was verified that the hydrogen bonding interaction between the CO group of plasticizers and α‐hydrogen of PVC exhibited in FTIR analysis was the main reason for the improvement of plasticizer performance of MH. Moreover, a new hydrogen bonding formed between SiOSi of MHA and the α‐hydrogen of PVC derived from XPS also caused the further improvement of plasticity for MHA.

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

“…Siloxanes exhibit also good thermal stability, hydrophobicity, and nontoxicity. Consequently, Ji et al [ 22 ] reported the use of poly(maleic acid hexanediol) ester (MH) modified with 10% (MHA-1) and 20% (MHA-2) of the maleic anhydride amount with 1,1,3,3-tetramethyldisiloxane (TMDS). The hydrosilylation reaction was carried out with the use of an unsaturated bond of maleic acid.…”

“…The most common types of intermolecular forces of attraction present in PVC–plasticizer blends are van der Waals forces, including dipole–dipole and dipole-induced dipole attractions, London dispersion forces, as well as hydrogen bonds. The dipole–dipole interactions occur between the polar groups of plasticizers, like carbonyl in ester linkages [ 21 ] or oxygen in Si-O-Si linkages [ 22 ] and chlorine atoms in PVC backbone. In a plasticizer molecule, a hydrogen bonding may appear between the carbonyl groups of the ester and the hydrogen attached to the carbon in an α position relative to the carbon–chlorine bonds in PVC [ 21 ].…”

“…Moreover, the changes in spectral features of the plasticizer molecule can be followed to evaluate its interactions with PVC. For instance, for an ester type plasticizers, signals connected to the C-O-C and carbonyl group stretching vibrations shift to the lower wavenumber because of an increase in an electron density of ester group and dipole–dipole interaction between hydrogen atoms at the α position of PVC and plasticizer’s carbonyl group [ 20 , 22 , 26 ].…”

An efficient plasticizer based on waste cooking oil: Structure and application

“…4,5 Among these plasticizers, phthalates occupy more than 75% of the consumption of all the plasticizers. 6,7 Nevertheless, the plasticizers of phthalate are carcinogenic and easily migrate out of the PVC. Furthermore, the migrated plasticizers will cause reproductive toxicity, 8 threaten human health and pollute the environment.…”

“…Recently, more than 6.4 million tons of plasticizers are produced worldwide per year, and most of them are used in PVC 4,5 . Among these plasticizers, phthalates occupy more than 75% of the consumption of all the plasticizers 6,7 . Nevertheless, the plasticizers of phthalate are carcinogenic and easily migrate out of the PVC.…”