New product development or major reformulation of high-durability exterior coatings is among the highest-risk projects a coatings lab can undertake. This is due to the years-long exterior exposure time required to validate a new product’s performance, in addition to the standard formulation and test cycle time of several months. There are many attributes associated with the assessment of a coating’s weatherability, such as grain crack resistance, adhesion, chalking, etc. In the architectural semi-gloss to high-gloss space, an emphasis has rightly been placed on gloss retention as a distinguishing attribute between high-performance and economy product classes.
Loss of gloss from exposure leads to not only a change in the desired aesthetic, but also provides the first visual indication of polymer degradation, and therefore, the initiation of additional property loss. It is important that the formulator utilizes all tools available to build confidence in their coatings as early in the formulation screening stage as possible, to ensure the right samples are selected for long-term, real-world exposure studies. We have employed a spectroscopic technique that differentiates UV durability on the order of weeks rather than months or years. This method uses time-resolved functional group analysis by ATR-FTIR and acts as an indicator of relative gloss durability in acrylic coatings.