Low-temperature decomposition of epoxy resin

Abstract

We report a new method using a heating medium for the thermal decomposition of epoxy resin (EP) at temperatures ranging from 50 to 200 o C. EP decomposition also occurred below 50 o C during a 6-day period to generate bisphenol A (BPA) at concentrations as high as 5 ppm. When polyethylene glycol was used as a heating medium, we determined the kinetics of the EP decomposition at low temperature. We determined the apparent activation energy of the overall decomposition to be 40.8 kJ/mol and the frequency factor to be 2.3 Ý10 3 by monitoring the rate of BPA formation. Thus, EP is clearly unstable upon the application of heat.

Predicting Drifting Polystyrene Degradation in World Oceans Based on Thermal Decomposition

“…2,36,37 As shown in Figure 1, detected chemicals may be derived from plastics degradation. BPA was derived from PC 38 or EPX, 39 and PAE was from polyvinyl chloride (PVC) plasticizer 40 and polyethylene terephthalate (PET).…”

“…However, SOs with constant ratios of SM:SD:ST = 1:1:5 do not occur naturally and are therefore degraded products from PS. ,, As shown in Figure , detected chemicals may be derived from plastics degradation. BPA was derived from PC or EPX, and PAE was from polyvinyl chloride (PVC) plasticizer and polyethylene terephthalate (PET).…”

“…Chemicals such as SOs from PS, BPA from PC or EPX, and PAE from plasticizers of PVC or PET are generated in the temperature range from 30° to 50 °C. ,− Unlike plastics (macromolecules), these chemicals are soluble in water and exert direct toxic effect on marine ecosystems.…”

Waste Polystyrene Degradation in the World Oceans: Newly identified sources of Contamination

“…Based on SO-free PS decomposition, one MT of puri ed PS was found to degrade at a rate of 0.3g per year at 30 °C, at an activation energy of 42.0 kJ mol -1 . 10,17 The careful decomposition of other thermoplastics at natural temperature range kinetically are generate into monomers at low activation energy (Extended Data sTable 4): the heat resistant plastics PC and EPX 22 generate BPA, PET and PVC generate PAE and polyurethane (PU) generate diisocyanate. The toxicity of these monomers is endocrine- 23 , teratogenic- 24 and reproductive- 23,24 affects and potentially mutagen or carcinogenic 24,25,26 is well known (Extended Data sTable 4).…”

Waste Polystyrene Degradation in the World Oceans: Newly identified sources of Contamination

“…Based on SO-free PS decomposition, one MT of purified PS was found to degrade at a rate of 0.3g per year at 30 °C, at an activation energy of 42.0 kJ mol -1 . 10,17 The careful decomposition of other thermoplastics at natural temperature range kinetically are generate into their basic structural units, monomers: the heat resistant plastics PC and EPX 22 generate BPA, PET and PVC generate PAE and polyurethane (PU) generate diisocyanate. The toxicity of these monomers is endocrine- 23 , teratogenic- 24 and reproductive- 23,24 affects and potentially mutagen or carcinogenic 24,25,26 is well known (Extended Data sTable 4).…”