The Study On Producing High Abrasion Tire Rubber By Gutta-Percha Substituting Part Of NR

Gutta-Percha material engineering theory points that Gutta-Percha can blend with rubbers. Because of having double bond in its structure, it is vulcanized conveniently when blended with other rubbers. Blending and vulcanization can gain excellent rubber materials.Under the direction of Gutta-Percha material engineering theory, the paper uses natural Gutta-Percha that substitutes part of NR to produce high abrasion tire rubber through blending with BR. The work including: formula selecting, observe microstructure of NR/BR/Gutta-Percha vulcanizate through SEM and TEM, study crystal behavior of Gutta-Percha in the vulcanizate through using DSC, discuss effects of crystal behavior of Gutta-Percha on the properties of vulcanizate, analyse dynamic mechanical properties and wet-skid resistance of vulcanizate by using DMA. The result shows that the formula (NR 50phr, BR 30phr, Gutta-Percha 20phr, stearic acid 5phr, magnesia 2phr, zinc oxide 2phr, antioxidant D 1phr, high abrasion fine furnace black 50phr, aromatic oil 5phr, sulfur 2phr, accelerant DM 2phr) is the most excellent. Comparison with traditional tire rubber, the vulcanizate of above formula has higher modulus at 100%, modulus at 300%, shore A hardness, abrasion resistance and flex cracking resistance, wet-skid resistance of the vulcanizate is also good, especially abrasion resistance and flex cracking resistance are much better, but its tensile strength, elongation at break and rebound resilience are a little lower. The blend that contains Gutta-Percha has a very good property of besieging roller, when placed and cooled, the blend is getting harder and harder. SEM photographs find that because of Gutta-Percha existence, compatibility of NR, BR, and Gutta-Percha becomes worse, and with Gutta-Percha content increasing, the compatibility of NR, BR, and Gutta-Percha is becoming worse and worse. TEM photographs show that the microstructure of NR/BR/Gutta-Percha vulcanizate belongs to distribution state of two different sea-island decentralization, and with Gutta-Percha content increasing, the microstructure of vulcanizate changes unobviously. DSC testing shows that Gutta-Percha still has crystal ability in the NR/BR/Gutta-Percha vulcanizate, crystal ability of Gutta-Percha decreases in the blend that contains the same Gutta-Percha content along with curing degree increasing, Gutta-Percha in the blend has no crystal ability when sulfur content is more than 3phr. Abrasion resistance and flex crackingresistance of vulcanizate reduce seriously along with curing degree increasing, in order to get vulcanizate that has fine abrasion resistance and flex cracking resistance, control sulfur content strictly that is less than 3phr. DMA testing shows that with Gutta-Percha content increasing, internal friction decreases, and improves dynamic mechanical properties. The tan 6 at 0°C is increasing along with Gutta-Percha content increasing.It is a very good way that natural Gutta-Percha substituting part of NR produces high abrasion tire.