Toughened aromatic poly-(decylene terephthalate) copolyesters with two renewable eugenol-based components via a random copolymerization method

Abstract

Poly-(decylene terephthalate) PDT homopolyester and two series of thermoplastic PDT 1−x M1 x and PDT 1−x M2 x copolyesters with varying molar compositions (x = 0%, 20%, 40%, 60%, 80%, 100%) were prepared via random copolymerization of dimethyl terephthalate (DMT) and 1,10-decanediol, with renewable eugenol-based subunits providing toughener properties. These eugenol-based tougheners were synthesized via a thiol-ene click reaction and subsequent nucleophilic substitutions. The obtained copolyesters exhibit averaged molecular weights (M w s) ranging between 26 800 and 55 300 g mol −1 , together with dispersity (D) values between 1.8 and 2.2. 1 H NMR, 13 C NMR and FTIR spectroscopic analyses were carried out as structural characterization techniques. The quantitative 13 C NMR spectra of PDT 1−x M1 x indicate that the copolyesters feature random microstructures. The results from thermogravimetric analysis (TGA) show that thermal stabilities of both PDT 1−x M1 x and PDT 1−x M2 x species gradually decrease with increasing toughener contents. Differential scanning calorimetry (DSC) and dynamic mechanical analysis (DMA) were carried out in order to study the thermo-mechanical properties of the polyesters.The toughener content proves to have no significant influence on the glass transition temperatures (T g s) of the copolyesters, despite the fact that an inconspicuous T g value was observed for the PDT homopolyester. Furthermore, the gradually diminishing melting enthalpy (ΔH m ) results from a decreasing crystallinity upon increase of the toughener unit content, suggesting that the incorporation of eugenol-based tougheners into PDT reduces the crystallinity in a significant manner. Isothermal crystallization and wide X-ray diffraction (WXRD) techniques provide evidence for this conclusion as well. The amount of eugenol-based units significantly influences the observed toughening effect. Strong tenacity of the brittle PDT was realized from the tensile and impact assays, with the content of the tougheners up to 20%.Specifically, the impact strength increases up to 16.4 and 15.8 kJ m −2 for PDT 80% M1 20% and PDT 80% M2 20% , respectively. Simultaneously, the ultimate strength decreases 2.6-4.3 MPa from 16.8 MPa to 12.5-14.2 MPa and elongation at break increases from approximately 5% to 18-20%. The findings described herein prove to be particularly important from a commercial point of view to meet the strict requirements for a variety of potential applications of such polyester species in structural materials. † Electronic supplementary information (ESI) available: Additional figures and Scheme S1. See

Recent progress in bio‐based eugenol resins: From synthetic strategies to structural properties and coating applications

“…Several studies have explored the EU‐based resin with other moieties such as polyester resin, 69 bismaleimide resin, 7,70 polybenzoxazine resin, 71 and cyanate ester resin 72 to improve the thermal properties and flame retardant. In recent decades, nitrogen, phosphorus, and silicon‐based resins have improved their FR efficiency 6,22 .…”

Synergistic interaction of renewable nipagin and eugenol for high performance aromatic copoly(ether ester) materials

“…23 Because of the multifunctionality (phenol and vinyl) and renewable nature of nipagin and eugenol, our group started to investigate polyester materials starting from them, whose thermal, crystalline, mechanical and degradable properties have been systematically investigated. 24,25 The influence of monomer structure on final properties was also studied. 26 However, the comprehensive performance of prepared polyesters was still improvable, regardless of the renewability of starting materials.…”

“…[29][30][31][32] Meanwhile, because the chain length of 1,6-hexandiol is shorter than 1,10-decanediol, the Tgs of obtained polyesters was enhanced obviously compared with our previously synthesized polyesters with 1,10-decanediol as the spacer. 25…”

Synergistic interaction of renewable nipagin and eugenol for aromatic copoly(ether ester) materials with desired performance

“…These two starting materials have been found widespread applications in fields of liquid crystalline material 14 , 15 , epoxy resin 16 – 18 , benzoxazine 19 , 20 , coating 21 , 22 , and Li–S battery 23 . Because of the multifunctionality (phenol and vinyl) and renewability of nipagin and eugenol, based on them our group has been dedicated to polyester materials, whose thermal, crystalline, mechanical and degradable properties have been comprehensively investigated 24 , 25 . The influence of monomer structure on final properties was also studied 26 .…”