The photooxidative stability of an aromatic segmented poly(urethane-urea) (PUU) elastomer, stabilised with a range of carbon black fillers, was assessed after very low UVA doses as a means to identify components that are highly susceptible to UV degradation, and suggest better design of such materials. Fourier-transform infrared (FTIR) analysis indicated rapid degradation of the urea bonds in the hard segments, followed by chain scission and photo-Fries reaction of the urethane linkages. In the soft segments, the oxidation of the original ether groups resulted in the formation of large amounts of ester groups, while some crosslinking of the ether groups was also evident. Carbon black provided moderate protection against degradation, with the smallest-sized particles being the most effective. Protection was evidenced by reduced surface cracking as well as an increased resistance to chemical changes in both the soft segments and hard segments. Even so, significant degradation was still evident at low UV doses suggesting that further stabilisation is required to increase the UV durability of these elastomers and improve their long-term performance.

在极低的UVA剂量后评估了用一系列炭黑填料稳定的芳族链段聚（氨基甲酸酯-脲）（PUU）弹性体的光氧化稳定性，以鉴定高度易受UV降解的组分，并建议更好地设计此类材料。傅立叶变换红外（FTIR）分析表明，硬链段中的脲键迅速降解，随后发生断链和氨基甲酸酯键的光-弗里斯反应。在软链段中，原始醚基的氧化导致大量酯基的形成，同时醚基的一些交联也很明显。炭黑提供了适度的抗降解保护，最小的颗粒是最有效的。通过减少的表面开裂以及增加的对软链段和硬链段的化学变化的抵抗力证明了保护作用。即便如此，在低紫外线剂量下仍显着降解，这表明需要进一步稳定化以提高这些弹性体的紫外线耐久性并改善其长期性能。