Commercial availability of fatty acid methyl ester (FAME) from palm oil targeted for biodiesel offers a good feedstock for the production of structurally well‐defined polyols for polyurethane applications. The effect of molecular weight (MW), odd and even carbon numbers, and the linear and branched structure reactants used in the ring‐opening reaction of epoxidized fatty acid methyl ester (E‐FAME) on the properties of polyols was investigated. Conversions of E‐FAME to PolyFAME polyols were confirmed by Fourier transform infrared analysis, oxirane oxygen content, and hydroxyl number. Gel permeation chromatography (GPC) calibrated against polyether polyols as a standard and vapor pressure osmometry were used for MW determination. GPC chromatograms of PolyFAME polyols clearly demonstrated the formation of oligomers during ring‐opening reactions. MW, and odd and even carbon numbers in a structure of linear diols and branched diol used in the syntheses of PolyFAME polyols did not have an effect on crystallinity, glass transition, or melt temperatures measured using Differential scanning calorimetry (DSC). PolyFAME polyols ring‐opened with water, methanol, and 1,2‐propanediol contained secondary hydroxyl groups, whereas PolyFAME polyols ring‐opened with linear diols contained a mixture of primary and secondary hydroxyl groups. It was found that the concentration of primary hydroxyl groups increased significantly by increasing the number of carbons from C2 to C3 in the linear diols. The viscosity of PolyFAME polyols also increased with the MW of linear diols used in the E‐FAME ring‐opening reaction. These findings would be beneficial for formulators in choosing the most cost effective polyols for polyurethane formulations.

The impact of replacing three polyether polyols with different levels of a single palm olein‐based natural oil polyol (NOP) was systematically correlated with the changes in foaming reactivity, cell structure, physico‐mechanical properties, and morphology of viscoelastic (VE) foams. The data show that replacing the polyether polyols with the NOP slightly increased the rate of the foaming reactivity. Increasing the NOP content resulted in increased cell size and cells remained fully open. Increased NOP content contributed to higher load bearing properties of VE foam, which can be attributed to higher functionality of NOP compared to polyether polyols. Addition of the NOP slightly increased the resilience of the foams, however, the hysteresis which is the measure of energy absorption remained mostly unaffected. Age properties, characterized by dry and humid compression sets, were mostly unaffected by the replacement of the polyether polyol with the NOP. The addition of NOP did not impact the morphology of the VE foam polymer matrix, which appears to retain a low degree of hard and soft segment domain separation. Overall, the results demonstrate a feasibility that the NOP can be used to partially replace the polyether polyols in VE polyurethane foams without significant impact on the functional performance.

Polyester polyols from renewable resources have gained significant interest in the field of polyurethane chemistry. Two sets of segmented TPUs were prepared from crystalline and amorphous azelate polyols, 4,4′‐methylenebis(phenyl isocyanate), and 1,4‐butanediol as a chain extender at a mole ratio of 1:2:1, respectively. Bio‐1,3‐propanediol (1,3‐PDO) and 1,5‐pentanediol (PTDO) were used to prepare crystalline azelate polyols, while 1,2‐propanediol (1,2‐PDO) and 2,2′‐dimethyl‐1,3‐propanediol (NPG) were used to prepare amorphous azelate polyols. All TPUs displayed clear glass transition temperatures (T gs) in between −36 and − 24 °C, associated with azelate polyols soft segments, which are decreasing with increasing diols chain lengths in azelate polyols. TPUs based on crystalline azelate polyols exhibited higher mechanical properties and better heat resistance in comparison to their counter parts. Besides, TPU based on 1,3‐PDO azelate showed lower percentage of hysteresis indicating lower heat build‐up. This is essentially good for TPUs that are to be used in dynamic applications such as rollers and wheels. Hence, the study on structure–property correlation of the crystalline and amorphous azelate polyols and their effect on TPUs properties suggest that crystalline azelate polyols are suitable for dynamic application of TPU, and amorphous azelate polyols are suitable for coatings and adhesives applications. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47890.

Research and developmental work of bio-based materials from both renewable resources and biotechnological processes have gained significant interest recently. In this study, bio-based azelaic acid has been used in combination with succinic and adipic acids to synthesize co-monomeric polyester polyol soft segments for thermoplastic polyurethanes (TPUs). Hysteresis of TPUs made from co-monomeric polyester polyols were significantly lower in comparison to the reference TPUs made from monomeric polyester polyols, indicating significant improvement in dynamic properties. In addition, tensile sets of TPUs prepared with co-monomeric polyester polyols were lower compared to TPUs prepared from monomeric polyester polyols, confirming excellent dynamic properties. Improved dynamic properties of TPUs based on co-monomeric polyester polyols can be ascribed to a phase-separated morphology which was quantified as the lowest fraction of bonded urethane from FTIR spectra, reduced crystallinity in differential scanning calorimetry thermograms, narrow tan δ peaks measured using dynamic mechanical analyses, and images from atomic force microscopy.

Azelate polyols of 2000 g mol−1 have been successfully prepared via esterification of renewable azelaic acid with linear diols containing different number of CH2 repeating units. Structure–property correlation of the azelate polyols had been evaluated in thermoplastic polyurethanes (TPUs). TPUs based on azelate polyols of longer chained linear diols with >4 CH2 repeat units retained higher degrees of crystallinity associated with the polyol soft segment. The ratio of hydrogen bonded urethane in the hard segment to free urethane phase mixed with the soft segment in the TPUs showed a complex oscillating dependence with increased number of CH2 repeating unit in the linear diols of azelate polyols. Correspondingly, static and dynamic properties of TPUs also showed the oscillatory dependence, whereby dynamic properties maximized with odd number of CH2 repeating unit and material strength maximized with even number of CH2 repeating unit. The results therefore can be used as guide to select appropriate azelate polyols to target specific TPU performance. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46258.