2. (horse rubber)Brown or nearly red marble texture block.
3. Horse rubber remains unchanged at 25 ~ 30 ℃, has plasticity at 60 ℃, and partially decomposes and melts at 100 ℃.
4. Horse rubber can absorb oxygen and become brittle under sunlight in the air.
5. Relative density 0.92.
6. Insoluble in water, slightly soluble in hot ethanol, soluble in chloroform and petroleum ether.