Aromatic copolyesters with enhanced crystallizability and mechanical properties by adding the renewable nipagin-based composition

Abstract

To improve the crystalline and mechanical properties of bio-based polyester materials, highly symmetrical nipagin-derived dimethyl ester is used for the synthesis of polyesters. Aromatic copolyesters, PDN2_1−xE1_x and PDN2_1−xE2_x (x = 0%, 10%, 20%, 30%, 40%, and 50%), with high crystallinity are synthesized from bio-based 1,10-decanediol, nipagin and eugenol-derived dimethyl esters via a random copolymerization method. The crystallizability of the copolyesters is emphatically investigated by the content of the two asymmetrical eugenol-derived compositions (i.e. E1 and E2). Not only the appearance of the copolyesters, which present a white powder consistently, but also differential scanning calorimetry (DSC), wide-angle X-ray diffraction (WXRD) and isothermal crystallization analyses verify the strong crystallizability of the copolyesters despite the fact that the crystallinity (X_c), melting point (T_m) and corresponding enthalpy (ΔH_m) are found to gradually decrease with the increase in the eugenol-based composition. Furthermore, the tensile assays demonstrate brittle characteristics of the copolyesters and further confirm the strong crystallizability of the nipagin-based PDN2, a potential candidate for replacement of the petroleum-based polyethylene (butylene) terephthalate (PET, PBT).