Visualizing curing process inside polymers

The curing process of polymer materials and structures has a crucial influence on their final properties. However, existing methods are only capable of characterizing their time-resolved information. To comprehensively reveal curing behaviors inside polymers, we report a method that combines optical coherence tomography and quantitative phase imaging for visualizing time- and space-resolved curing degree (or curing rate) distributions. For validation, the curing process of a polymer droplet was monitored by using the proposed method, which not only revealed that the curing rate of the polymer surface is faster than that of the interior but also discovered the depth-dependent gelation process. The experimental results indicate that the proposed method can effectively reveal curing behaviors inside polymers, which opens new possibilities for better understanding curing kinetics.