Thermal and mechanical properties of thermoplastic urethanes made from crystalline and amorphous azelate polyols

Abstract

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.

Renewable Polyurethanes from Sustainable Biological Precursors

“…254 Both crystalline and amorphous renewable azelate polyols were created to study applications in urethane uses, where the former exhibited mechanical properties suitable for applications requiring heat and abrasion resistance, whereas the latter was suggested for use in coatings and adhesives. 255 When compared to polyols made from shorter diacids such as adipic acid, azelate polyols produced thermoplastic PUs with improved hydrolytic stability. 256 5.4.2.…”

Polyurethane: Recent Engineering Contributions

“…Variation of mass, flexural strength and viscoelastic response are determined in order to find the changes of the composite [53]. A comparison of TPU/GO and TPU/reduce GO showed that the reduction of GO is not always necessary [54]. The dynamo-mechanical, thermal and mechanical characteristics of long glass fiber reinforced TPU / poly (butylene terephthalate) polyblend have been studied.…”

“…Using melt-blending a hybrid made of a shape memory TPU with GO and montmorillonite (MMT) was produced. Thermal analysis showed that GO-MMT enhanced the thermal decomposition of TPU composites [56]. Expandable graphite (EG) is often added to PUs to prevent their flammability.…”

“…From crystalline azelate polyol and amorphous azelate polyol two sets of segmented TPUs were prepared. Their study showed that the crystalline azelate polyols are suitable for dynamic applications and the amorphous ones are suggested for coatings and adhesives [12]. The product of 1-butene methatesis of canola triacylglicerol with shortened structure, terminal double bonds and oligomers was used to synthesize novel polyols and PU foams.…”

High Bio-Content Thermoplastic Polyurethanes from Azelaic Acid

“…Dicarboxylic acids are one of the main ingredients for making polyester polyols for polyurethane applications and are key building blocks for TPUs. Recently, aliphatic polyesters from bio-derived carboxylic acids have been explored for use in renewable TPUs [ 15 , 16 , 17 ]. Given that we can source azelaic acid from microalgae, the most sustainable photosynthetic biomass, we have focused our attention on developing polyurethanes from this monomer [ 18 ].…”