Thermoplastic elastomers derived from bio‐based monomers

Abstract

Series of copolyesters based on poly(propylene succinate) (PPS) and poly(butylene succinate) (PBS), which can be produced from biological feedstock, and postconsumer poly(ethylene terephthalate) (PET) were synthesized with the aim of developing sustainable materials, which combine the mechanical properties of high performance elastomers with those of flexible plastics. The aliphatic polyesters were synthesized by the catalyzed two‐step transesterification reaction of dimethyl succinate, 1,3‐propanediol, and 1,4‐butanediol followed by melt reaction with PET in bulk. The content of PET segments in the polymer chains was varied from about 10 to 100 wt % per 100 wt % PPS or PBS. The effect of the introduction of the PET segments on the structure, thermal, physical, and mechanical properties was investigated. The composition and structure of these aliphatic/aromatic copolyesters were determined by NMR spectroscopy. The thermal properties were investigated using differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The level of crystallinity was studied by means of DSC and wide‐angle X‐ray scattering. A depression of melting temperature and a reduction of crystallinity of copolyesters with increasing content of PET segments were observed. Consequently, the tensile modulus and strength of copolyesters decreased, and the elongation at break increased with PET content in the range of 10−50 wt %. Thus, depending on PET content, the properties of copolyesters can be tuned ranging from semicrystalline polymers possessing good tensile modulus (380 MPa) and strength (24 MPa) to nearly amorphous polymer of high elongation (∼800%), and therefore they may find applications in thermoplastics as well as elastomers or impact modifiers. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 39815.

Trends in Polyester Upcycling for Diversifying a Problematic Waste Stream

“…Much of the appeal derives from the ability to finely tune the properties of the resulting copolymers by simply adjusting the chemical nature and ratios of the feedstocks. An early demonstration of this concept involved the transesterification between poly­(propylene succinate) (PPS) or poly­(butylene succinate) (PBS) and high molar mass rPET (i.e., not modified, postconsumer) . This afforded essentially near-random copolyesters, suggesting extensive transesterification, and tailored mechanical properties across a broad spectrum (Scheme ).…”

Multiblock Polyesters Demonstrating High Elasticity and Shape Memory Effects

“…One widely used ABA triblock thermoplastic elastomer is polystyrene- b -polybutadiene- b -polystyrene (SBS) which exhibits high elasticity, moderate stress at break, and an operating temperature range from −90 to 100 °C. Although widely applied, poly­(styrene)- b -polyolefin- b -poly­(styrene) materials are generally produced using conventional petrochemical raw materials; one alternative is to develop degradable block polymers which may even derive from renewable resources. ,− …”

Utility of Chemical Upcycling in Transforming Postconsumer PET to PBT-Based Thermoplastic Copolyesters Containing a Renewable Fatty-Acid-Derived Soft Block

“…Typically, rPET is chemically depolymerized in an initial step, followed by repolymerization with various comonomers to form copolymers . Alternatively, rPET has been reacted directly with various functional building blocks to form diverse copolyesters, plasticizers, or resins. − This has been done with several biobased bifunctional comonomers such as isosorbide , or fatty acid derivatives, , but this approach routinely leads to oligomers lacking mechanical integrity. Our interest lies in generating high molar mass segmented copolymers, generically called thermoplastic copolyesters (TPCs) possessing high-performance mechanical properties, using a direct, one-pot reaction pathway from rPET …”