First of all, which parts of the cold resistance are shown, the rubber molecular chain will decrease with the decrease of temperature, and the hardness, modulus and intramolecular friction will increase. When a certain low temperature is reached, the molecular chain will freeze and the hardening will completely lose its elasticity. Or the elastomer is "plasticized." While this temperature is the Tg glass transition temperature, not all temperatures of the low temperature resistant materials are indicated by Tg because they are not suitable for some amorphous materials.
Let's talk about the factors affecting the low temperature resistance of each component of the formulation.
It can be said that the most important thing in TPE/TPR is SEBS/SBS, and the impact is also the biggest. Styrene and butadiene are hardness and soft segments, respectively, so the lower the styrene content, the better the low temperature resistance of TPE/TPR.
For non-crystalline elastomer materials, the lower the crosslink density, the better the low temperature resistance of the material. The TPE without chemical crosslinking is naturally better than the TPV.
3. Selection of softening oil
Oils such as white oil can reduce the hardness of the elastomer, and have some beneficial effects on the low temperature resistance. However, when selecting white oil, try to choose oils with lower pour point.
4. Selection of filler
Fillers can not be used as much as possible. If necessary, choose some soft or spherical fillers. Although the addition of fillers will not significantly affect the Tg glass transition temperature, it will affect the hardness, modulus and intramolecular friction at low temperatures. So you need to think about it.