Study On Multi-Phase System Morphology And Thermal Resistance Of EPDM

Ethylene-propylene-diene terpolymers (EPDM) is a synthetic rubber and contains pendant unsaturation on main structure; it is inherently resistence to degradation by heat, light and oxygen. By study on vulcanization, filler and multiplicity crosslinking system, search the influence of different compounding ingredients to preference.Semi-efficient vulcanization system can form compact corss-linking networks, keep rubber mechanical properities in high tempreture. On conventional vulcanization syetem, sulfer is a key factor, second is sulfer donor- DTDM & TMTD. TMTD can affect hot-air aging; accelerator PZ can speed up vulcanization process. Antioxident can not help heat aging resistence due to unsaturation of EPDM.Super abrasion furnace (SAF) carbon black can help to improve mechanical properities in high tempreture; proper amount of silica can also improve heat tensile strength and tear strength. Plasticiser paraffin will not affect mechanical properities in normal and high temperature. Crystallization of EPDM can affect multiplicity crosslinking system on mechanical properities. Adding less then 40 phr IIR in EPDM can improve hot-air tensile strength and tear strength.Multiplicity crosslinking system with sulfer, sulfer donors and peroxide get excellent heat aging resistence properties. Acidity accelerator TMTD will affect decomposition of DCP, it is recommended to apply DTDM as main accelerator. Peroxide DCP will decompose during aging process which will create new crosslinking networks, increase of DCP amount can help to improve heat aging resistence.The dynamic properties of rubber sample measured by RPA shows that with the increase amount of IIR, the dynamic modulus of EPDM compound increase with increasing of frequency, decrease with increasing of temperature and strains, loss factor increased. After vulcanization, properties of EPDM vulcanizates dynamic modulus and loss factor are almost the same as EPDM compound, with the increase of temperature, dynamic modulus and loss factor reach peak at 70℃.