I. Overview

The glass transition temperature of polymer has a direct impact on the film forming temperature of lotion. Generally, the higher the glass transition temperature of polymer is, the higher its low film forming temperature is.

The factors affecting the glass transition temperature of polymers are not only related to the type and quality of monomers used in the synthesis of the polymer, but also to the relative molecular weight of the polymer and the type and quantity of plasticizers added.

The larger the molecular weight of a polymer, the higher its glass transition temperature

If an external plasticizer is used in the resin, it will lower the glass transition temperature of the polymer, and the amount of decrease in glass transition temperature is generally proportional to the amount of plasticizer added.

When the configuration of functional monomers in copolymers is opposite, the glass transition temperature will increase due to the attraction of functional groups.

When the copolymer contains hydrophilic functional groups, it will lower the glass transition temperature.

For room temperature dry coatings, low glass transition temperature is beneficial for film formation. Low glass transition temperature polymer films have low surface hardness and poor stain resistance, but good elasticity.

For drying latex coatings used in assembly lines, when the glass transition temperature of the polymer is low, foaming is prone to occur during the drying process. At this time, it is necessary to use polymers with the highest glass transition temperature possible to reduce the chance of latex particles on the surface of the paint film forming a film before water evaporation.