Advanced Polymerization and Properties of Biobased High T_g polyester of Isosorbide and 1,4-Cyclohexanedicarboxylic Acid through in Situ Acetylation

Abstract

The synthetic problems associated with melt polymerizations to form homopolyesters of isosorbide (ISB) and rigid diacids could potentially be solved by using catalyst systems with acetic anhydride (Ac 2 O). A catalyst consisting of dibutyltin oxide, germanium oxide, and Ac 2 O exhibited excellent performance characteristics in syntheses of a highmolecular-weight homopolyester of ISB and cis/trans-1,4-cyclohexanedicarboxylic acid (CHDA), also referred to as poly(isosorbide cis/trans-1,4-cyclohexanedicarboxylate) (PICD). The acetylation of ISB using Ac 2 O during esterification decreased the steric hindrance of ISB and accelerated the chain growth of PICD. Gel permeation chromatography data confirmed the formation of a highmolecular-weight PICD (71 100 weight-average molecular weight and 14 300 number-average molecular weight) using 0.02 mol of Ac 2 O. The glass transition temperature of PICD was almost 131°C at 0.02 mol of Ac 2 O and decreased with increasing amounts of Ac 2 O due to the breaking of the rigid ring of ISB at higher concentrations of Ac 2 O. The structure of opened ring ISB was confirmed using two-dimensional nuclear magnetic resonance (NMR) and distortionless enhancement by polarization transfer NMR. ■ INTRODUCTION1,4:3,6-Dianhydrohexitol, a biobased material that can be derived from biomass such as wheat, sugar, and corn, has been used in various polymer preparations, pharmaceuticals, and cosmetics. 1−6 It has three stereoisomers which are isosorbide (ISB), isomannide, and isoidide, respectively obtained from glucose, mannose, and fructose. 7,8 Among its three stereoisomers, ISB is the most easily accessible and affordable monomer for polymer synthesis 8,9 and is one of the most favorable candidates for renewable monomers used in addressing environmental issues and the depletion of petroleum resources. 10 When ISB is used as a monomer of polyester, the resulting polyester is not only environmentally desirable, but also has superior thermal and optical properties due to its molecular rigidity and the chirality of its asymmetrical hydroxyl groups. Several reports describe attempts to synthesize various polymers containing ISB, including polyesters, 11−24 polyurethanes, 25−29 epoxy, 30,31 polyamides, 32,33 polycarbonates, and liquid crystalline polymers. 34−38 In homopolyesters made with ISB, the incorporation of terephthalic acid (TPA), an aromatic diacid, results in materials with high thermal stability and desirable mechanical properties. However, the formation of a homogeneous system during polymerization is problematic because both TPA and ISB are solid powders and TPA does not dissolve in ISB melts. 13 Furthermore, the low reactivity and volatility of ISB make it difficult to obtain a high-molecular weight polymer. Previous studies by Quintana et al. 10 describe syntheses of polyterephthalates from ethylene glycol (EG), 1,4-cyclohexanedimethanol (CHDM), and ISB. They reported the number-average molecular weights (M n ) and weight-average molecular weights (M w ) of PE(CIs)T terpolyester conta...

Tandem mass spectrometric analysis of isosorbide‐1,4‐cyclohexane‐dicarboxylic acid polyester oligomer cations using ion‐trap mass spectrometry

“…ISB‐CHDA polyester oligomers were synthesized using the previously described procedure . The ISB‐CHDA polyester oligomer sample was prepared at 0.3 mg/mL in a 1:1 (v/v) water/methanol solution, to which a few drops of NaCl or CH 3 COOH solution were added.…”

“…[24][25][26][27] EXPERIMENTAL ISB-CHDA polyester oligomers were synthesized using the previously described procedure. [28] The ISB-CHDA polyester oligomer sample was prepared at 0.3 mg/mL in a 1:1 (v/v) water/methanol solution, to which a few drops of NaCl or CH 3 COOH solution were added. ESI-MS experiments were carried out on an ion-trap mass spectrometer (LCQ Deca, Thermo Scientific, San Jose, CA, USA) operated in positive ion mode.…”

Branched poly(1,4-butylene carbonate-co-terephthalate)s: LDPE-like semicrystalline thermoplastics

“…More than 200 million tons of polymers are produced annually from petroleum, almost all of which are persistent in the ecosystem, creating environmental issues such as “plastic island.” One of the most significant challenges in polymer science and industry is the production, preferably using renewable resources, and utilization of biodegradable polymers that have comparable thermal/physical properties and processibility. Aliphatic polyesters have been studied as the biodegradable sustainable polymers . Polylactide (PLA), polyhydroxyalkanoate (PHA), and poly(1,4‐butylene succinate) (PBS) are currently on the market to promote the industrial applications of sustainable polymers .…”

Partially bio-based polyimides from isohexide-derived diamines

“…8,10 Due to their desirable structural features, isohexides have been extensively investigated as bio-based building blocks for a variety of polymers including polyesters, [12][13] polycarbonates, [14][15] poly (ester amide)s, 16 poly (ester imide)s, 17 polyurethanes, [18][19] and polyethers. 20 The incorporation of isohexides into polymer backbones can lead to several benefits, such as high glass transition temperatures (T g ) and special optical properties.…”