The most important property of thermoplastic elastomer TPR is its similarity to vulcanized rubber at room temperature. typical tensile strength of TPR is about 30 MPa and elongation is 800%, values that are much higher than those of non-reinforced vulcanized SBR and PB for at least two reasons; first, the molecular network of extended diolefins leads to the formation of PS block micro-regions, which not only act as crosslinks but may also have a filling effect; second, the slippage of diolefin molecular chain entanglements increases the tensile strength. The tensile strength of TPR increases with the rise of St content or molecular weight, and the use temperature also increases with the rise of the molecular weight of styrene block.

　　There are three main factors that affect the yellowing resistance of TPE, TPR transparent or light-colored material, one is the type and origin of the rubber base material, the second is the type of operating oil, and the third is the addition of anti-UV agent.

　　First of all, look at the rubber base material. First of all, TPE with SEBS as the base material has better yellowing resistance than TPR with SBS as the base material. This is because SEBS is the hydrogenation product of SBS thermoplastic rubber. According to the hydrogenation theory mentioned above, the yellowing resistance of TPE transparent material is better than the yellowing resistance of TPR transparent material.

　　Again look at the type of operating oil, some poor quality operating oil, easy to cause TPE transparent material yellowing, so the operating oil manufacturer's production and processing process is very important. Choose the white oil with more hydrogenation times, which can improve its yellowing resistance. In addition, adding antioxidant or anti-aging agent in the operation production process can improve the yellowing resistance of the operating oil.

　　For some transparent or white TPE products with high yellowing resistance requirements, you can consider adding anti-UV agents to the TPE formulation to enhance the yellowing resistance of the material.

　　Most factories currently use naphthenic oil and paraffin oil. Naphthenic oil has better bonding with SBS and SEBS, but it is sticky, while paraffin oil is a straight chain alkane with a smooth feel.

　　-Yellowing resistance - refers to the resistance of the light-colored material to the oxidizing medium when it encounters the strong electronegative (strong oxidizing) medium (or antioxidant), if the resistance of the material to the oxidizing medium is poor, the material is prone to oxidation and yellowing, and the yellowing resistance is poor.

　　Hydrogenation - unsaturated bond (usually refers to carbon-carbon double and triple bonds, but also contains other unsaturated bonds between atoms) of organic or polymeric compound molecules, under the appropriate conditions of action (such as temperature, pressure, initiator and catalyst, etc.) and hydrogen atoms undergoing addition or agglomeration reaction, the destruction of unsaturated double or triple bonds, so that the hydrogen atoms and the original unsaturated bond between the atoms to form a more stable chemical bond (such as carbon-hydrogen single bond). After hydrogenation, at the microscopic level, the chemical stability, oxidation resistance and yellowing resistance of the material are enhanced due to the formation of a more stable single bond structure.