Polyesters from renewable resources with glass transition temperature (T g) higher than 100 C are crucial in broadening their application range. In this work, a series of high molecular weight copolyesters, poly(butylene bis [4-(2-hydroxyethoxy) phenyl] sulfone 2,5-furandicarboxylate) (PBSF), was synthesized from bis[4-(2-hydroxyethoxy) phenyl] sulfone (BHEPS), bio-based 1,4-butanediol (BDO), and 2,5-furandicarboxylic acid (FDCA) via transesterification. Nuclear magnetic resonance spectroscopy (1 H-NMR and 13 C-NMR) was used to confirm their chemical structures, composition, and sequence distribution. Characterizations demonstrated that with the increasing content of BHEPS unit, T g of synthesized polyesters was increased from 38.2 C for PBF to 122 C for PBSF-95, in which the content of BHEPS unit was 95%. However, the weight average molecular weight (M w) of PBSF was dramatically decreased after the addition of BHEPS, from 95,300 g/mol for PBF to only 9600 g/mol for PBSF-95, which was too low for practical application. Taking molecular weight, T g , and mechanical properties into account, PBSF-65 was considered to be a promising polyester with M w of 28,500 g/mol, T g of 104.7 C, tensile strength of 82 MPa, and elongation-at-break of 98%. Besides, it was a completely amorphous polyester with a transmittance of 89.9% by cutoff at 700 nm. Summarily, PBSF-65 showed great potential to be used as raw material for the manufacture of baby bottles, children's toys, kitchen appliances, and beverage packaging, especially in the case when high transparency and heat resistance are required.

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Poly(butylene terephthalate‐co‐butylene 2,5‐furandicarboxylate) copolyesters (PBTFs) were synthesized from 1,4‐butanediol, dimethyl terephthalate (DMT), and 2,5‐furandicarboxylic acid (FDCA) by a two‐step polymerization method. Their chemical structures were confirmed by Fourier‐transform infrared spectroscopy, proton nuclear magnetic resonance spectroscopy, and carbon nuclear magnetic resonance before thermal properties were explored with differential scanning calorimeter and thermogravimetric analyzer. Results showed that PBTFs changed from semi‐crystalline to completely amorphous when the content of FDCA unit was increased to 45 mol% at first, and then became crystallographic again with the further increment of FDCA unit to 75 mol%. For their mechanical properties, the tensile modulus and strength showed the similar trend, decreasing firstly and then increasing later. Their barrier to carbon dioxide and oxygen became better with the increasing of furan content due to the rigidity and higher polarity of furan ring. The performance of PBTFs copolyesters was investigated clearly, and the relative content of FDCA and DMT can be adjusted to satisfy different performance requirements.

A novel high-speed disperser equipped with a rotor of simple structure is proposed to intensify the process of polymer devolatilization, which is almost indispensable in polymer manufacturing. Experiments on the rate of acetone removal from highly viscous acetone-syrup solution were conducted under di erent operating conditions. The results indicated that, as the absolute pressure decreased, the acetone removal rate increased gradually and the removal of acetone was derived successively from di usion and foam devolatilization. Meanwhile, the acetone removal rate increased with increasing rotor rotational speed and initial acetone concentration, but decreased with increasing inlet ow rate. Besides, based on our previous work on the dimension and ow characteristics of highly viscous liquid laments, a semi-empirical model of devolatilization was established to describe the process of di usion devolatilization. A comparison between the experimental data and modeling results showed that the semi-empirical model was able to provide reasonable estimates of the acetone removal rate in di usion devolatilization.