Scalable Synthesis of Poly(ester-co-ether) Elastomers via Direct Catalytic Esterification of Terephthalic Acid with Highly Active Zr–Mg Catalyst

Abstract

The poly(ester-co-ether)s (PEEs) comprising poly(butylene terephthalate) and poly(tetramethylene glycol) (PTMG) segments were cost-efficiently synthesized by direct esterification of terephthalic acid (TPA) and 1,4-butandiol (BDO)/PTMG with M n of 1000 in one feeding step by a unique nontoxic Zr−Mg catalyst that is designed and synthesized in our laboratory, avoiding undesirable eco-hazardous cocatalyst and byproducts that must be produced when terephthaloyl chloride (TPC) and dimethyl terephthalate (DMT) were chosen. The structure of the Zr− Mg catalyst and PEEs was systematically analyzed by high-resolution 1 H NMR, ATR-FTIR spectroscopies, and X-ray diffraction. The size-exclusion chromatography suggested that the weight-average molecular weight of the PEEs reaches up to 60 600 g/mol. In particular, the ether-segment retention, molecular weight, melt processability, and mechanical properties of the PEEs are significantly higher by Zr−Mg catalyst than by Ti−Mg and traditional tetrabutyl titanate (TBT) catalysts. DSC and DMA analyses revealed that the PEE copolymers obtained by the Zr− Mg catalyst have random segment distribution, glass transition temperature down to −34 °C, and good elasticity and strong toughness at ambient temperature. TBT is an efficient catalyst for the polycondensation between TPC/BDO or DMT/BDO prepolymers and PTMG for synthesizing excellent PEEs, unfortunately accompanying with the usage of toxic and expensive bases and the formation of hazardous HCl or methanol byproducts. This study confirmed that TBT is not powerful enough to achieve high-molecular-weight and thus tough PEEs via the environ-benign direct polycondensation among TPA, BDO, and PTMG anymore, while the Zr−Mg catalyst developed here is active enough to catalyze the direct polycondensation without compromise or toxic discharge. Furthermore, the TPA-based PEE elastomers demonstrate potential to replace current eco-unsafe elastomers like rubbers, polyurethane, polyolefin, and TPC-/DMT-based PEEs.

Bio-Based Pentamethylenediamine-Derived Semiaromatic Copolyamide: Controllable Synthesis and Discoloration Mechanism

“…Polyamide is synthesized by polycondensation of the lactam monomer or diacid and diamine monomer and is widely used in textile fibers, functional film materials, and engineering plastics owing to its excellent heat resistance, mechanical strength and toughness balance, wear resistance, and solvent resistance. , However, the monomers used for polyamide polymerization rely on fossil resources, which do not meet the needs of green and low-carbon development. Although bio-based feedstocks such as castor oil, , 2,5-furandicarboxylic acid, − itaconic acid, − dimer acid, sebacic acid, decanediamine, − and lactate have been used to prepare polyamides, suitable bio-based monomers still need to be developed to prepare bio-based polyamide with excellent performance.…”

Mechanically versatile isosorbide‐based thermoplastic copolyether‐esters with a poly(ethylene glycol) soft segment

“…They are commonly found in high performance areas, owing to the typical durability, thermo oxidative stability, and highly tunable mechanical profile 5 . This is an area ripe for further interrogation, and developments into efficient production and sustainable improvements in manufacturing are on‐going 6 . TPEE's typically consist of multiple segments (i.e., blocks), with one type being a relatively rigid or hard segment (i.e., high T g /T m ) and the other a flexible or soft segment (i.e., low T g ) (Figure 1A).…”

Development of Sustainable Citric Acid-Based Polyol To Synthesize Waterborne Polyurethane for Antibacterial and Breathable Waterproof Coating of Cotton Fabric

“…17 synthesize functional polyol. 73 Hence, the second option is quite lucrative, easily achievable in the case of polyurethane due to its affordability and industrial applications. This research work is aimed to make waterborne waterproof breathable PU with inherent antibacterial property using novel bio-based polyols from an affordable, eco-friendly, and renewable material, that is, citric acid.…”

“…The first one is economically and industrially nonfeasible as it involves the use of electrospinning technology for making nanoporous membranes. ,− ,− Polyurethane can be tailor-made using various kinds and different combinations of polyol and isocyanide according to the desired property. For example, optimum composition hydrophilic and hydrophobic polyol can be used to make partially hydrophilic films. ,,, Li et al had explored the use of a bi-carboxylic acid compound like terephthalic acid to synthesize functional polyol . Hence, the second option is quite lucrative, easily achievable in the case of polyurethane due to its affordability and industrial applications.…”