Blooming on Polymers

Discolorations on polymers are often caused by phase separation of the material's components. This phenomenon is often referred to as polymer blooming and is caused by the incompatibility of certain additives with the polymer or other ingredients. 
Figure 1 shows an optical microscope image of crystalline defect on Polypropylene (PP), that was analyzed with Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS). For a definite identification of the crystal components, the chemical composition of the surface was recorded in imaging mode. Figure 2 shows the presence of lithium stearate (blue). The region of the crystal is characterized by the stabilizer Ultranox 626 (green) and the base polymer (PP, red).  The crystalline needle structure is clearly observable.  The height of the enriched additive material was 8 µm.