【摘要】 鉴于三元乙丙橡胶（EPDM）与改性甲基乙烯基硅橡胶（NMVQ）具有一定的相容性，通过改变EPDM/NMVQ共混胶的硫化时间来调控两相交联网络状态，并研究该状态对共混胶动态力学性能、耐高温性能、耐老化性能及耐水蒸气性能的影响。结果表明，随着硫化时间的延长，EPDM相的交联密度快速增加，其弹性模量从与NMVQ相接近的水平逐渐偏离，使得EPDM/NMVQ共混胶的力学强度既受总交联程度的影响，又受两相弹性模量匹配程度的作用，最终拉伸强度呈现先上升后下降的趋势。当硫化时间为307 s时，EPDM/NMVQ共混胶具有较好的力学性能，常温下拉伸强度可达13.0 MPa、扯断伸长率可达414%,150℃下拉伸强度可达5.6 MPa、扯断伸长率可达249%；当硫化时间为685 s时，该共混胶的耐老化性能较好。采用NMVQ对EPDM改性可提高其耐水蒸气性能，EPDM/NMVQ共混胶在120℃水蒸气中老化72 h后拉伸强度仍可达6.8 MPa、扯断伸长率可达236%，相较于EPDM硫化胶分别提高了21.43%和101.71%。更多还原

【Abstract】 Based on the compatibility between ethylene-propylene-diene rubber(EPDM) and modified methyl vinyl silicone rubber(NMVQ), the twophase crosslinking network state was regulated by changing the vulcanization time of EPDM/NMVQ blends, and the effects of the two-phase crosslinking network state on the dynamic mechanical properties,high-temperature resistance, aging resistance and water vapor resistance of the blends were studied.The results showed that with the extension of vulcanization time, the crosslinking density of EPDM phase increased rapidly, and its elastic modulus gradually deviated from the level close to that of NMVQ, so that the mechanical strength of EPDM/NMVQ blends were affected by both total crosslinking degree and matching degree of two-phase elastic modulus, and the final tensile strength showed a trend of increase first and then decrease. When the vulcanization time was 307 s, the EPDM/NMVQ vulcanizates had good mechanical properties. The tensile strength could reach 13.0 MPa and elongation at break could reach 414% at room temperature, while the tensile strength could reach 5.6 MPa and elongation at break could reach 249% at 150 ℃. When the vulcanization time was 685 s, the aging resistance of blends was better. The water vapor resistance of EPDM could be improved by modified EPDM with NMVQ. The tensile strength and elongation at break of EPDM/NMVQ blends could still reach 6.8 MPa and 236% after aging for 72 h 120 ℃ at water vapor,which were 21.43% and 101.71% higher than those of EPDM vulcanizates, respectively.更多还原