Action mechanism of ester lubricant
During plastic processing, ester lubricants can regulate the processability of materials and then the structure and performance of the finished products, so that the processing can be successfully stopped with comprehensive benefits under the given material and equipment conditions and the finished products with the desired quality can be consumed, that is, energy consumption and material consumption. The output is therefore costly.
So, how does ester lubricant play a role in plastic processing?
It is generally believed that the internal lubrication mechanism of ester lubricants is a pseudo plasticizing mechanism. Therefore, in daily life, oxidized polyethylene wax is also called plasticizer.
At the thermoplastic processing temperature, the polymer chains are separated by the compatible oxidized wax molecules dissolved in the melt, which increases the distance between the polymer chains. Although the distance only needs the molecular level, the intermolecular force is a short-range interaction force, which is sufficient to effectively reduce the interaction force between PVC polymer chains. So as to promote the plasticization of PVC.
The reason why the internal lubrication mechanism of ester lubricants is a "false" plasticizing mechanism is that plasticizers have plasticizing effect at both thermoplastic processing and application temperature, while ester lubricants only have plasticizing effect at thermoplastic processing temperature. In order to achieve this effect, it is obvious that the compatibility of ester lubricants that play the role of internal lubrication is lower than that of plasticizers. The meticulous request is that they are high enough at the thermoplastic processing temperature and low enough at the application temperature. The compatibility of ester lubricant and PVC should be low enough at the application temperature to avoid reverse plasticizing effect of plasticizer at low dosage, which leads to increased brittleness of products.