硫化体系对246型氟橡胶耐高温性能的影响

研究N，N’-双肉桂叉基-1，6-己二胺（3#硫化剂）和双酚AF／苄基三苯基氯化磷（BPP）硫化体系对246型氟橡胶硫化特性、物理性能和耐高温性能的影响。结果表明，选用2份3#硫化荆或并用比为1．5／0．6的双酚AF／BPP硫化体系的氟橡胶各项性能较好;相对而言，3#硫化剂氟橡胶的拉伸性能较好，硬度较低，有利于加工;双酚AF／BPP硫化体系氟橡胶物理性能和加工性能稍差，但耐高温性能较好。     

二元乙丙橡胶与四丙氟橡胶的并用研究

将二元乙丙橡胶与四丙氟橡胶并用采用过氧化二异丙苯／三烯丙基异氰脲酸酯作为共硫化体系，测出了不同并用比硫化胶的一些性能，结果表明，并用胶所选用的共硫化体系是成功的，并有和胶性能优良。     

丙烯酸酯橡胶/液体氟橡胶并用胶性能的研究

研究液体氟橡胶用量对丙烯酸酯橡胶(ACM)/液体氟橡胶并用胶性能的影响。结果表明:加入液体氟橡胶,并用胶的t_(10)延长,t_(90)缩短,F_L和F_(max)减小,加工性能提升;ACM与液体氟橡胶相容性良好,并用胶的耐寒性能有所下降;随着液体氟橡胶用量的增大,并用胶的物理性能、热空气老化性能、热稳定性能和耐油性能先提高后降低,压缩永久变形增幅增大;当液体氟橡胶用量为5份时,并用胶的综合性能较佳。     

吸酸剂和加工助剂对246型氟橡胶耐高温性能的影响

试验研究吸酸剂和加工助剂种类与用量对氟橡胶耐高温性能的影响。结果表明，不同吸酸剂对氟橡胶性能的影响不同，其中轻质氧化镁氟橡胶耐高温性能优良；添加32#机油为加工助剂的氟橡胶焦烧时间延长，流动性提高，热老化后各项性能保持率良好；32^#机油和硬脂酸铅并用可大幅降低氟橡胶门尼粘度，改善氟橡胶加工性能，对氟橡胶物理性能和耐热老化性能无不利影响。优化配方为：氟橡胶100，炭黑N99020，轻质氧化镁10，32#机油4.     

并用比对氟橡胶/氟硅橡胶并用胶性能的影响

将氟橡胶与氟硅橡胶/硅橡胶混炼胶并用,制备氟橡胶/氟硅橡胶并用胶,研究氟橡胶/氟硅橡胶并用比对并用胶性能的影响。结果表明:随着氟硅橡胶用量增大,并用胶的脆性温度降低,耐低温性能明显提高;当氟橡胶/氟硅橡胶并用比为8/2时,并用胶的微观结构未出现明显分层现象,物理性能较好。     

环保法生产氟橡胶复原胶的研究

为解决传统再生胶脱硫工艺污染性较大的问题,研发了一种化学断硫环保生产新工艺,并最终制得了复原氟橡胶。实际应用时,采用氟橡胶与复原氟橡胶并用基本可保持氟橡胶所有性能,并大幅降低产品成本;复原氟橡胶分别与丙烯酸酯橡胶、丁腈橡胶并用时可大幅提升耐介质性能和耐高温性能。     

含氟烯烃类氟橡胶加速硫化性能的研究

从配方设计的角度出发，研究了胺类和双酚类硫化体系对含氟烯烃类氟橡胶的加速硫化作用。结果表明，采用3#／BPP／双酚AF的并用体系对含氟烯烃类氟橡胶有明显的加速硫化作用。     

环己烷混合液对定子橡胶摩擦磨损行为影响的研究

研究丁腈橡胶(NBR)与氟橡胶(FPM)在环己烷与基础油(20~#机油)混合液中浸泡溶胀和摩擦磨损行为。结果表明:在环己烷混合液中,随着浸泡时间的延长,NBR的质量、硬度和弹性模量变化较大,FPM的质量、硬度和弹性模量变化很小;随着混合液中环己烷比例和负荷的增大,NBR和FPM的磨损量和摩擦因数均增大,FPM的快速磨损转变点的负荷大于NBR;混合液中环己烷比例和负荷较小时,FPM的磨痕较轻;混合液中环己烷比例和负荷较大时,定子橡胶应选择性能更优的FPM,混合液中环己烷比例和负荷较小时,可以选择性价比高的NBR。     

几种耐油橡胶材料的γ辐射效应研究

研究了氟橡胶(FPM)、丁腈橡胶(NBR)和氢化丁腈橡胶(HNBR)3种耐油密封材料的力学性能和耐油性能在不同剂量γ射线作用下的变化,结果表明,在0～200kGy辐射吸收剂量范围内,FPM、NBR和HN-BR的硬度、定伸应力及拉伸强度增大,拉断伸长率降低;FPM和HNBR无论辐照与否,均具有优异的耐热和耐油性能;NBR无法在150℃长期工作。本研究所得试验数据,对优选在射线辐射环境中使用的橡胶密封材料具有实际意义。     

氟橡胶的并用改性研究进展

氟橡胶的特殊性能是由其分子中固有的氟原子结构特点所决定的,但氟橡胶也存在不足之处,如弹性差、撕裂强度低、耐低温性能欠佳、易压缩变形、生胶加工性能差等。为了提高氟橡胶及其制品的性能,国内外学者对氟橡胶进行了大量的改性研究工作,包括主链改性、并用改性、填充改性和表面改性等,其中并用改性具有工艺简单、成本低廉、易于推广等优点,是开发高分子材料新品种的重要途径。本文详细综述了目前氟橡胶并用改性的研究状况。     

Replacement of virgin rubbers by waste ground vulcanizates in blends of silicone rubber and fluororubber based on tetrafluoroethylene/propylene/vinylidene fluoride terpolymer

This study reports the results of investigations on blends of silicone rubber and fluororubber based on tetrafluoroethylene/propylene/vinylidene fluoride terpolymer and the effects of replacement of silicone rubber and/or fluororubber in their 50/50 blend by the respective vulcanizate powders of known compositions. To simulate the aging condition of factory wastes, the silicone rubber or fluororubber vulcanizates were aged for 72 h at 200°C and then converted into powder by mechanical grinding. The fluororubber vulcanizate powder (FVP), mostly spherical in shape with average diameter varying between 2 and 10 μm, exists in a highly aggregated state displaying chainlike structures that, however, break down during blending with virgin rubbers. The silicone rubber vulcanizate powder (SVP) is irregular in shape, with larger particles in the range of 30–100 μm, and the smaller particles exist in highly aggregated chainlike structures, as in the case of FVP, which break down during milling to mostly spherical particles of 2–10 μm in diameter. Measurements of physical properties reveal that the blends of silicone rubber and fluororubber are technologically compatible. SEM photomicrographs of THF‐etched samples show the biphasic structure of the blends, in which the fluororubber forms the dispersed phase in a continuous silicone rubber matrix of lower viscosity. Replacement of silicone rubber in the 50/50 silicone rubber/fluororubber blend by its vulcanizate powder (SVP) increases the Mooney viscosity, but replacement of fluororubber in the blend by its vulcanizate powder (FVP) has little effect on the Mooney viscosity. Monsanto rheometric studies reveal that replacement of silicone rubber by SVP or fluororubber by FVP in the 50/50 silicone rubber/fluororubber blend increases the minimum rheometric torque but decreases the maximum torque, and the effect is more pronounced in the case of SVP. Furthermore, the replacement of silicone rubber in the blend by SVP causes a decline in the physical properties (25% replacement causing about 10% decline in properties, for example), whereas even 75% replacement of fluororubber by FVP has little effect on the physical properties. When both silicone rubber and fluororubber are partially replaced by SVP and FVP in the same blend, properties of the resulting blend composition are controlled more by SVP incorporation, whereas fluororubber replacement has only a marginal effect on blend properties. It is evident from dynamic mechanical spectra that the blends are immiscible in all compositions and addition of SVP or FVP does not affect the glass–rubber transitions of the constituent polymers. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 2326–2341, 2001     

Influence of fluorine interface to the crystallization of poly (vinylidene fluoride)/silicone rubber/fluororubber elastomeric tertiary blends via dynamical curing

ABSTRACT

We demonstrate the influence of fluorine interface to the crystallization of poly(vinylidene fluoride) (PVDF)/silicone rubber (SR)/fluororubber (FKM) tertiary dynamic curing blends. In contrast to PVDF/SR binary blend, the average size of PVDF spherulites turns smaller and the crystallization rate is lower in PVDF/SR/FKM tertiary blend when more fluororubber component was added into the blends at the same crystallization temperature. Incorporation of FKM does not change the crystalline form of PVDF in the blends. The resulting mechanical properties of tensile strength, flexural strength, Izod impact strength and elongation at break for PVDF/SR/FKM tertiary blends are enhanced compared with PVDF/SR binary blend.     

氟橡胶/甲基乙烯基硅橡胶共混弹性体的性能

通过机械共混法制备了氟橡胶(FKM)/甲基乙烯基硅橡胶(MVQ)弹性体,研究了二者的质量比对共混弹性体力学性能、耐油性能和动态力学性能的影响.结果表明,当FKM/MVQ(质量比,下同)为80/20时,共混弹性体具有较好的综合力学性能.随着FKM所占比例的增加,共混弹性体的耐油性能提高.当振动频率为1 Hz时,共混弹性体中MVQ相的玻璃化转变温度(Tg)比MVQ的Tg提高了约5.0 ℃,而FKM相的Tg改变不大;当FKM/MVQ为60/40时,随着振动频率由1 Hz增大到50 Hz,FKM相的Tg升高了12.9 ℃,而MVQ相的Tg变化不大.     

Effects of blend ratio and vulcanizate powders on the processability of silicone rubber/fluororubber blends

While silicone rubber has a much lower shear viscosity than that of fluororubber, the viscosity of silicone rubber/fluororubber blends is closer to that of silicone rubber. All rubber compositions show pseudoplastic behavior. While the viscosity of a 50/50 silicone rubber/fluororubber blend increases on replacement of the silicone rubber by silicone rubber vulcanizate powder (SVP), the effect of fluororubber replacement by the corresponding fluororubber vulcanizate powder (FVP) on the shear viscosity is less pronounced. The difference in viscosity between SVP‐replaced silicone rubber and FVP‐replaced fluororubber becomes less prominent at higher shear rates. Fluororubber exhibits a higher extrudate die swell than that of silicone rubber. The die swell of the silicone rubber/fluororubber blends is higher than are the figures obtained by the additivity rule. Replacement of constituent rubbers in the blend by the corresponding vulcanizate powders causes an increase in the die swell. While the silicone rubber extrudate surface is smooth, the fluororubber extrudate shows melt fracture. The extrudate surfaces of the silicone rubber/fluororubber blends are similar to that of the silicone rubber extrudate. Replacement of constituent rubbers by the corresponding vulcanizate powders increases the roughness of the extrudate surface, which is more prominent in the case of silicone rubber replacement by SVP. SVP can replace 50% of silicone rubber and FVP can replace 75% of fluororubber in the 50/50 silicone rubber/fluororubber blend. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 2377–2387, 2003     

白炭黑/炭黑混合填料对氟橡胶/硅橡胶共混胶性能的影响

采用沉淀白炭黑和高耐磨炭黑作为氟橡胶/硅橡胶共混胶的填料.研究以不同质量比混合的沉淀白炭黑和高耐磨炭黑对氟橡胶/硅橡胶共混胶的硫化特性、门尼粘度、力学性能、耐热老化性能和耐油性能的影响,并通过RPA分析表征填料-填料的相互作用,采用SEM表征白炭黑/炭黑混合填料在氟橡胶/硅橡胶共混胶中的分散性.结果表明,随着混合填料中白炭黑所占比例的增大,氟橡胶/硅橡胶共混胶的硫化转矩升高,焦烧时间(t10)缩短,正硫化时间(t90)延长,门尼粘度增大.氟橡胶/硅橡胶共混胶的力学性能,耐热老化性能和耐油性能都随着混合填料中白炭黑用量增多而提高.RPA分析表明,全部采用白炭黑补强的共混胶Payne效应最明显,炭黑补强的共混胶Payne效应最弱.SEM分析表明,白炭黑在共混胶中分布比炭黑更加均匀,填料聚集体粒径较小.     

The effects of technological compatibility for silicone rubber/fluororubber blends

In this study, silicone rubber (SR) and fluororubber (FKM) blends were prepared and their properties were investigated. The crosslinking rate in the blends was increased with increase of SR content due to the silica filler existing into SR. As the content of FKM in the blends increases, the thermal decomposition temperature of the blends tended to increase and the thermal stability of 25/75 SR/FKM blend was higher than that of any other blends ratios. With the increase of FKM content in the blends, the contact angle of SR/FKM blends decreased and the surface energy increased owing to the change of the polarity of the surface. Dynamic mechanical analysis of 25/75 SR/FKM blend showed two transitions peak at −60.5 and −12.7°C, respectively, indicating the immiscibility. Fourier transform infrared attenuated total reflectance studies showed shifts in the peaks due to specific interactions in the blends, and field emission scanning electron microscopy (FE-SEM) studies revealed that the domain sizes of the blends come to be smaller with increasing FKM content. In the blend with 75 wt % of FKM, we observed that it is technologically compatible due to the increase of physical properties and the decrease of the domain size of FE-SEM in 25/75 SR/FKM blend. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Effects of waste ground fluororubber vulcanizate powders on the properties of silicone rubber/fluororubber blends

We prepared fluororubber (FKM) vulcanizate powder (FVP) via cryogenic grinding of the FKM commonly used in automobiles and assessed the particle size distribution of the resulting powder. We also prepared silicone rubber (SR)/FKM blends at a ratio of 25/75. Varying amounts of FKM were replaced with equal amounts of FVP within the range of 5–40 wt%, and the physical properties of the resulting SR/FKM/FVP blends were investigated and compared. The TGA curves of the SR/FKM/FVP blends obtained during the thermal property investigations indicated that pyrolysis of SR occurred within two temperature ranges, and that the SR/FKM/FVP blends with 5 wt% FVP demonstrated the highest thermal stability. The storage modulus (E') and loss modulus (E″) of the SR/ FKM/FVP blends increased as the FVP content increased. In the SR/FKM/FVP blends with 5 and 10 wt% FVP, very typical elastic‐deformation behavior was observed. On the contrary, in 40 wt% FVP, the rubber properties disappeared. The mean particle size of FVP was 41.75 μm, and particle size distribution measurements of the SR/FKM/FVP blends suggest particle coexistence such that FVP was condensed and separated. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

硅橡胶并用改性研究进展

介绍了国内外硅橡胶与三元乙丙橡胶、丙烯酸酯橡胶、氟橡胶、聚氨酯橡胶、二烯类橡胶、丁基橡胶等并用的研究情况和各种并用胶的优缺点。指出硅橡胶与其他橡胶并用的关键问题是相容性和共硫化特性。     

耐机油氟橡胶的研制

本文研究了填料、助剂对氟橡胶的影响,采用高分子量和低分子量并用技术研制了耐机油性氟橡胶。试验结果表明,当高分子量氟橡胶F—26和低分子量氟橡胶TP—2配比为75/25时,氟橡胶的机械性能和耐油性能最佳。     

改性氟橡胶及其在汽车工业上的应用研究进展

氟橡胶(FKM)是主链或侧链的碳原子上含有氟原子的合成高分子弹性体,具有优异的综合性能。对氟橡胶的性能、改性及其在汽车工业上的应用作了综述,并对改性氟橡胶在汽车工业的应用前景作了展望。