Synthesis and properties of polyesters derived from renewable eugenol and α,ω-diols via a continuous overheating method

Abstract

Two eugenol-based aromatic dimethyl terephthalate (DMT)-like monomers were prepared via thiol-ene click reaction and subsequent nucleophilic substitution reactions with methyl chloroacetate or 1,4-dibromobutane. Two series of thermoplastic polyesters derived from renewable eugenol and linear aliphatic α,ω-diols HO-(CH2)n-OH (n = 2, 3, 4, 6, 10, 12) were successfully synthesized. These prepared polyesters have weight-average molecular weights in the range of 18500-90500 g mol -1 , and polydispersities (PDI) between 1.8 and 2.2. Their chemical structures were all accurately characterized by 1 H NMR, 13 C NMR and FTIR. The random microstructures of synthetic polyesters were also explored by 13 C NMR. The obtained polyesters all exhibit thermal stability above 330°C. More importantly, the thermal stability, the maximum degradation rate and residue weight are intimately associated with the length of the linear aliphatic α,ω-diol. Their thermo-mechanical properties were studied by the differential scanning calorimetry (DSC) and dynamic mechanical analysis (DMA). The length of linear aliphatic α,ω-diol shows crucial influence on the glass transition temperature (Tg). With the gradually increase of the α,ω-diol length, the Tg of the synthesized polyester uniformly exhibits a tendency of decreasing. The polyesters are all amorphous materials at room temperature, whose Tg values range from -28.4 to 7.6°C. The incorporation of aromatic eugenol into the polyester chains reduces the crystallinity obviously, as well as the mechanical properties compared with conventional PET or PBT. The Young's modulus and ultimate strength are just in the range of 1.2-6.9 MPa and 0.96-3.37 MPa, respectively. On the contrary, the elongation at break reaches up to 840-1000%, indicating the excellent viscosity properties for such unmanageable viscous materials.

Bio‐based aromatic copoly(ether ester)s with enhanced toughness and degradability: Influence of insertion of phenoxy‐ether linkage and eugenol‐derived composition on properties

“…This phenomenon indicates that the eugenol-based compositions are more susceptible to be oxidized than nipagin-based composition. More surprisingly, the dispersity values of the copoly(ether ester)s are found to be between 1.7 and 1.9, which are rather low and monotonous compared to our previously reported solely eugenol-based poly(ether ester)s with dispersity values between 1.8 and 2.2, 29 and furthermore carbohydrate-based polyesters with dispersity values ranging from 2.3 to 2.5. 7,8 This result reveals that the two dimethyl ester groups in nipaginderived N1 have the same reactivity which is different from FIGURE 1 The different constitutional resonances of the methylenes adjacent to the hydroxy-oxygens for PDN1 1-x E1 x copoly(ether ester)s with the indications of the dyads to which they are assigned.…”

“…It has been previously reported that when the polycondensation temperature exceeds 220 8C, the colors of polymers vary from transparent gradually into crimson and even black with the proceeding of polymerization. 29 As observed from Table 1, the isolated states of the resulting polymers are closely related with the compositions. That is, with the content of eugenol-based composition gradually increasing, the physical states vary from white powder for PDN1, transit into light yellow powder for PDN1 90% E1(2) 10% , PDN1 80% E1(2) 20% and subsequently light yellow solid for PDN1 70% E1(2) 30% and PDN1 60% E1(2) 40% , and finally become yellow viscous solid for PDN1 50% E1(2) 50% .…”

Aromatic poly(ether ester)s derived from a naturally occurring building block nipagin and linear aliphatic α,ω-diols

“…The overhead stirring was replaced by the magnetic stirring, which has been veried to be easy-operation and ensure the ideal blend of monomers and oligomers and the nal molecular weights. 9 The detailed polymerization routes are shown in Scheme 2. For long-chain a,u-diols (n ¼ 6, 10, 12), a 1 : 1.05 molar ratio of dimethyl ester to a,u-diol was sufficient to obtain the expected molecular weight and ensure hydroxyl termination.…”

“…8 Furthermore, the mechanical properties of the materials synthesized from these bio-based resources are far from satisfactory compared to petroleum-based materials like PET and PBT. 9 All of these factors limit the use of carbohydrates and vegetable oils in practical applications. Hence, it is necessary to further explore renewable substitutes for fossil resources in order to produce structural materials with excellent thermal and mechanical properties and scale up the production to an industrial level eventually.…”

Bio-Based Aromatic Copolyesters: Influence of Chemical Microstructures on Thermal and Crystalline Properties

“…Bio-based polymer materials are attracting more and more attention from both academic and industrial aspects, especially for the synthesis and modification of bio-based degradable polymers (polyester, polyurethane, and polycarbonate) [5][6][7][8]. Recently our group has been dedicated to the study of bio-based polyester materials [9,10]. The initial monomer design and polymerization method have been used to improve the final property, however, strong demand still exists for the acquisition of high-performance bio-based polymeric materials [11][12][13][14].…”