Synthesis of Biobased Polyester Polyol through Esterification of Sorbitol with Azelaic Acid Catalyzed by Tin(II) Oxide: A Kinetic Modeling Study

Abstract

A sustainable and renewable biobased polyester polyol for polyurethane production was synthesized through the esterification of azelaic acid and sorbitol catalyzed by tin­(II) oxide in a batch system. The studies on chemical equilibrium, reaction kinetics and important operating parameters were carried out. The temperature, molar ratio of sorbitol to azelaic acid and catalyst loading were varied in order to determine the best reaction conditions. The polyester polyol synthesized was tested for its fatty acid content through titration. The best operating condition found was at reaction temperature of 433 K, sorbitol to azelaic acid molar ratio of 4:1 and catalyst loading of 2 wt %, yielding 72% azelaic acid conversion after 6 h of reaction. The presence of minute amount of sorbitan and isosorbide inferred the potential of sorbitol-based branched polyester formation with its backbone incorporated with these sorbitol anhydrides. The equilibrium study validated the endothermicity of the reaction. Meanwhile, the kinetic data well fitted to the Langmuir–Hinshelwood Hougen Watson (LHHW) model with the activation energy of 14.43 kJ/mol.

Heterogeneous Double Metal Cyanide Catalyzed Synthesis of Poly(ε-caprolactone) Polyols for the Preparation of Thermoplastic Elastomers

“…As shown in the 1 H NMR spectra in Figures S32-S34 in the Supporting Information, the characteristic signal of the glycidol units appeared at 3.40-3.90 ppm along with the signals of the CL segments, and its intensity increased with increasing glycidol feed ratio. The formation of the branched polyester was also confirmed by 2D and 13 C NMR spectra (see Figure S35 and S36, Supporting Information). In the 1 H NMR spectrum, the triplet signal at 3.64 ppm that decreases with increasing of glycidol in the feed are assigned to the terminal groups of CL whereas the signals at 3.79, 2.84, and 3.15 ppm also indicated that the copolymers were partially end-capped with epoxy groups, as observed in the DMC-catalyzed ROMBP of glycidol [50].…”

“…Polyesters are typically synthesized via two main pathways: (i) polycondensation of aliphatic dicarboxylic acids and (ii) ring-opening polymerization (ROP) of cyclic carboxylic esters [12,13]. ε-Caprolactone (CL) and lactide are among the most prominent and intensively studied cyclic ester monomers for the synthesis of polyesters.…”

Review on the Impact of Polyols on the Properties of Bio-Based Polyesters

“…Multifunctional monomers such as citric acid or tartaric acid have been incorporated to act as secondary cross-linkingcross-linking agents to improve the mechanical properties of PSS ( Figure 5). The resulting polyesters, poly(sorbitol-co-citrate-co-sebacate), PSCS, and poly(sorbitol-co-tartaric-co-sebacate), PSTS showed significant improvements in mechanical properties [103] [104]. They found that the preferred reaction conditions to achieve the highest monomer conversion are a temperature of 160 • C, sorbitol to azelaic acid molar ratio of 4:1 and 2 wt% catalyst content.…”

“…The Young's modulus, tensile strength, and elongation at break of the PSTS are 7. 15 Kamaruzaman et al synthesized poly(sorbitol-co-azelate) (PSAz) in bulk catalyzed by tin oxide (ii) [104]. They found that the preferred reaction conditions to achieve the highest monomer conversion are a temperature of 160 °C, sorbitol to azelaic acid molar ratio of 4:1 and 2 wt% catalyst content.…”

Heterogeneous Double Metal Cyanide Catalyzed Synthesis of Poly(ε-caprolactone) Polyols for the Preparation of Thermoplastic Elastomers

“…Polyesters are typically synthesized via two main pathways: (i) polycondensation of aliphatic dicarboxylic acids and (ii) ring-opening polymerization (ROP) of cyclic carboxylic esters [13,14]. ε-Caprolactone (CL) and lactide are among the most prominent and intensively studied cyclic ester monomers for the synthesis of polyesters.…”