（a）Weathering resistance
　　UV and solar rays may cause TPU to become brittle. This change begins at the surface and the material turns yellow, which may lead to the mechanical properties of the material. But it can be avoided by adding UV stabilizer and Yan Fu. Test method: VDE472-805 standard.

　　（b）Resistance to substances, gasoline and grease, acid substances and alkaline solutions.
　　Chemicals will change the properties of TPU materials. The resistance energy to specific chemicals is mainly determined by the concentration and temperature of cheese. In general, TPU has better resistance to gasoline and wetting oil, but if TPU is added to gasoline and wetting oil, the additives and pollutants contained in the material may lead to irreversible damage. TPU has good resistance to ASTM test gasoline, even if it is stored at 100 C for several weeks. At room temperature, TPU can be placed in dilute acid substances and alkaline solutions for a short time.

　　（c）Fire resistance
　　There are a variety of evaluation standards and requirements for the fire performance of TPU. For the cable industry, VDE804TestB is usually evaluated. The FMVSS302 is adopted in the steam industry. All grades meet this requirement. UL94 is an important international standard. Its flame retardancy can not reach HB grade, flame retardant IROGAN 78P4766 for yellow card name, UL 94 VO, thickness between 1.5-2.2 mm. A 85 P and A 85 P 4380 are usually evaluated by V2 and VO, depending on the thickness of the sample. The yellow card project has been applied.

　　（d） What is the resistance to microbiological attack?
　　TPU based on PE is usually used in the field of microbiological attack. According to DIN57472 (VDE472-804), its saponification value is lower than 200mgKOH/g. Meet the requirements of VDE 0282-10.