Aryl sulfonic acid catalysts: Effect of pendant group structure on activity in hydrolysis of polyethylene terephthalate

Abstract

A series of aryl sulfonic acids were tested as catalysts for acid hydrolysis occurring at the surface of poly(ethylene) terephthalate (PET) particles. Specifically, p‐toluenesulfonic acid monohydrate (PTSA), 2‐naphthalenesulfonic acid (2‐NSA), and 1,5‐naphthalenedisulfonic acid tetrahydrate (1,5‐NDSA) were chosen to provide sulfonic acid active groups and varying hydrophobic functionality. The effect of catalyst concentration and reaction temperature on PET hydrolysis rate was studied. The aryl sulfonic acid catalysts exhibited much higher rates of PET hydrolysis than the mineral acid, H2SO4. At 150°C and 4 M catalyst, the time required to achieve more than 90% TPA yield was 3, 3, and 8 h, and 18 h for (PTSA), (2‐NSA), (1,5‐NDSA), and H2SO4, respectively. Ethyl acetate hydrolysis was performed as a model reaction to probe the activity of the catalysts in homogenous reactions to compare with the heterogenous hydrolysis reaction occurring at the PET surface. The higher catalytic activities for PET hydrolysis of the PTSA, 2‐NSA, and 1,5‐NDSA than H2SO4 was attributed to improved wetting by the reaction media and affinity of the aryl sulfonic acid catalysts for the PET surface.

Effect of electrolyte and carbon material on the electrochemical performance of high-voltage aqueous symmetric supercapacitors

“…To test the electrodes wettability [43,44], the deionized water droplets of 0.2 lL were formed at the end of the syringe and deposited at random locations on each material surface. The reported contact angle values were averaged on ten measurements.…”

Depolymerization within a Circular Plastics System

“…102 An in-depth probing into aryl sulfonic acid catalysts by Abedsoltan et al was revealing. 103 Using PTSA, 2-naphthalenesulfonic acid (2-NSA), and 1,5-naphthalenedisulfonic acid (1,5-NDSA) PTSA, 2-NSA, and 1,5-NDSA respectively. Interestingly the bifunctional 1,5-NDSA was a slower and less active catalyst than PTSA.…”

“…Yang et al used p -toluenesulfonic acid (PTSA) and achieved a 96.2% TPA yield after 90 min at 150 °C, while maintaining this performance across 5 cycles . An in-depth probing into aryl sulfonic acid catalysts by Abedsoltan et al was revealing . Using PTSA, 2-naphthalenesulfonic acid (2-NSA), and 1,5-naphthalenedisulfonic acid (1,5-NDSA) (Figure ), >90% TPA yields were observed at 150 °C.…”

“…102 An in-depth probing into aryl sulfonic acid catalysts by Abedsoltan et al was revealing. 103 Using PTSA, 2-naphthalenesulfonic acid (2-NSA), and 1,5-naphthalenedisulfonic acid ( (Figure 5), >90% TPA yields were observed at 150 °C. However, longer reaction times were needed of 3, 3 and 8 h for PTSA, 2-NSA, and 1,5-NDSA respectively.…”

Mechanism and kinetics of enzymatic degradation of polyester microparticles using a shrinking particle–shrinking core model

“…Shrinking Particle (SPM) and Shrinking Core (SCM) models are widely used to describe transport phenomena in solid-fluid chemical reactions, [19][20][21][22][23][24][25] including polymer degradation. [26][27][28][29][30][31] These models by themselves can describe homogenous acid or base hydrolysis of polyethylene terephthalates, but cannot accurately describe the multi-step heterogenous enzymatic degradation of polymers. We postulated that a combined Shrinking Particle (SPM) -Shrinking Core (SCM) model which accounts for each step involved in polymer degradation would more accurately reflect the enzymatic degradation kinetics of polymer microparticles, compared with previously developed kinetic models.…”