What is the reason for the poor thermal stability of PC / ABS plastic bottles?

- Dec 19, 2019-

In general, the thermal stability of PC / ABS plastic bottle is related to the thermal stability of PC and ABS. However, due to the strong polar ester group, which is highly susceptible to trace water, acid ions of PC, ABS in the thermal conditions and degradation synthesis of residual additives, therefore, the PC part is a part of the crucial impact on the thermal stability of PC / ABS, and therefore requires more attention.


PC plastic bottles are easy to degrade. On the left is the structure of personal computer and various chemical bond conditions, which can occur in a simple high-temperature isopropyl chain fracture, high shear conditions, carbonate bond rearrangement reaction, and in a small amount of water, alcohol, ABS resin schematic synthesis of residual alkaline electrolyte and catalyst, flame retardant, HALS greatly increase the degradation rate of metal salt, the following rights are schematic electricity The brain is degraded by alcohol and attack.


In addition, the current PC plastic bottle manufacturers usually have terminated the treatment in the synthesis process, but there are still some residual hydroxyl groups, especially in some products with high mobility and internal wide molecular weight distribution.


Therefore, in order to solve these problems, we can start to improve the method by adding antioxidants and granules to fully dry. The free radical mechanism of the decomposition of antioxidants and hydrogen peroxide produced in the process of degradation by capture, but the water and alcohol produced are difficult to play a role, and due to the migration itself, the basic factor of the product will be damage. However, the strong sensitivity of ester group of water content in PC treatment is less than 0.02%, and the following is the impact of drying time and temperature on water content of PC material. As can be seen, in order to obtain the following safety line of moisture content, the granular material needs to be dried at least at 120 ℃ for more than 4 hours, then many plants can meet this condition due to the influence of equipment, efficiency and other factors.