硅橡胶/氟橡胶共混胶的硫化及热稳定性

采用机械共混法制备了质量比为10/90的硅橡胶/氟橡胶共混胶,研究了共硫化体系和硫化条件对其力学性能的影响,并通过傅里叶变换红外光谱分析了其化学组成,通过动态力学分析研究了其结构相容性,用热重法探讨了其热稳定性。结果表明,最佳的共硫化体系为过氧化二异丙苯/三烯丙基异三聚氰酸酯体系,一段硫化宜为温度170℃、压力10 MPa、时间30 min,二段硫化宜为温度200℃、时间6 h。在共混胶中硅橡胶与氟橡胶存在部分的相容性;少量硅橡胶的加入可以拓宽氟橡胶的使用温度,使其耐热性能有所提高,耐低温性能有所改善。     

白色填料对氟橡胶/硅橡胶共混胶性能的影响

研究了气相法白炭黑、沉淀法白炭黑、硅藻土、硅酸钙和氟化钙对氟橡胶/硅橡胶共混胶的力学性能、耐热老化性能、耐油性能和低温性能的影响,并通过橡胶加工分析(RPA)表征填料对氟橡胶/硅橡胶共混胶的补强作用.结果表明,有填料的共混胶的力学性能、耐油性能和脆性温度比无填料时明显升高;填充气相法白炭黑的共混胶的力学性能、耐热老化性能和耐油性能最好.RPA分析表明,气相法白炭黑对共混胶的补强作用最好.     

氟橡胶与硅橡胶共混胶的性能研究

研究了氟橡胶(FKM)与硅橡胶(MVQ)共混胶以及采用氟硅橡胶(FSR)为增容剂制作的FKM/MVQ共混胶性能。结果表明,氟橡胶与硅橡胶共混可改善氟橡胶的耐低温性能,但其力学性能降幅较大;以氟硅橡胶为增容剂可改善2种橡胶的相容性,其共混胶兼具硅橡胶的耐热性和耐寒性、氟橡胶的耐油性,成本较低。     

共混比对氟橡胶氟硅橡胶共混胶性能的影响

氟橡胶是一种主链及侧链上的碳上连接有氟原子的一种合成高分子弹性体。氟橡胶具有优异的耐油、耐高温、耐酸碱、耐高真空等性能,同时由于氟原子的存在,使分子链极性增加、耐低温性能变差,这极大限制了氟橡胶的应用范围。笔者拟通过将其与氟硅橡胶共混来改进氟橡胶低温性能。我们选用苏威公司生产型号为PL958的氟橡胶,该规格氟橡胶具有自由基硫化反应位点,可以与氟硅橡胶实现共硫化。结果表明,氟橡胶/氟硅橡胶共混比为8:2时,共混胶具有优异的综合性能。     

氟橡胶与硅橡胶共混物及其制备方法

氟橡胶与硅橡胶共混物及其制备方法     

MVQ-g-TFEMA对氟橡胶/硅橡胶共混胶的增容作用

通过高温力化学接枝法制备硅橡胶接枝甲基丙烯酸-2,2,2-三氟乙酯(MVQ-g-TFE-MA),作为氟橡胶/硅橡胶共混胶的增容剂。研究增容剂用量对氟橡胶/硅橡胶共混胶的力学性能、耐油性能和低温性能的影响,采用DMA研究共混胶中氟橡胶和硅橡胶的相容性。结果表明,添加的MVQ-g-TFEMA的质量分数为4.6%时,共混胶具有良好的力学性能。随着增容剂的质量分数从0增至11.5%,共混胶的耐油性能提高,脆性温度从-36.8℃下降至-48.3℃。DMA分析表明,增容剂MVQ-g-TFEMA改善了共混胶中氟橡胶和硅橡胶的相容性。     

气相白炭黑对氟橡胶／硅橡胶共混胶性能的影响

采用气相白炭黑补强氟橡胶／硅橡胶共混胶。研究了气相白炭黑的用量和比表面积对氟橡胶／硅橡胶共混胶的力学性能、耐热老化性能和耐油性能的影响,并采用SEM观察了共混硫化胶的拉伸断面形貌。研究表明,随着气相白炭黑的用量从0份增加到50份,气相白炭黑的比表面积从120m^2·g^-1增大到380m^2·g^-1,共混胶的力学性能和耐油性能提高,而耐热老化性能下降;当气相白炭黑用量为40份,且比表面积为220m^2·g^-1时,共混硫化胶具有较好的综合性能。SEM照片表明,随着气相白炭黑用量增大,其在氟橡胶／硅橡胶共混胶中的分散均匀性下降;当气相白炭黑比表面积为220m^2·g^-1时,气相白炭黑的分散性较好。     

氟橡胶/甲基乙烯基硅橡胶共混胶的性能

研究了氟橡胶(FKM)与甲基乙烯基硅橡胶(MVQ)的共混比、1,4-双叔丁基过氧异丙基苯(BIBP)硫化剂和三烯丙基异三聚氰酸酯(TAIC)助硫化剂用量以及硫化温度对FKM/MVQ共混胶硫化性能和力学性能的影响。结果表明,当FKM/MVQ共混比为50/50、硫化剂BIBP用量为1.0份、助硫化剂TAIC用量为2.5份、硫化温度为160℃时,FKM/MVQ共混胶的硫化性能和力学性能最优,硫化时其最大转矩为19.34 dN·m,拉伸强度为5.29 MPa,扯断伸长率为230.68%。     

氯醚橡胶/超细全硫化粉末硅橡胶共混物的结构与性能

采用熔融共混工艺制备氯醚橡胶(ECO)/超细全硫化粉末硅橡胶(UFPSiR)共混物,并对共混物的相态结构与性能进行研究.结果表明,UFPSiR在ECO中的分散性较差,粒径为微米级;UFPsiR与ECO的相容性不好,ECO/UFPSiR共混物的物理性能与ECO/硅橡胶共混物差别不大,但耐热氧老化性能较好,加入少量UFPsiR能够显著减小共混物的压缩永久变形.     

再生硅橡胶/甲基乙烯基硅橡胶共混物的性能

采用机械剪切破碎法制备再生硅橡胶,并将其掺入到甲基乙烯基硅橡胶中制备再生硅橡胶/硅橡胶共混物,研究了再生硅橡胶含量、硫化促进剂2,5-双(叔丁基过氧化)-2,5-二甲基己烷和沉淀法白炭黑用量对共混物硫化特性和力学性能的影响,通过傅里叶变换红外光谱、动态力学分析仪和扫描电子显微镜对共混物和硅橡胶进行了分析。结果表明,随着共混物中再生硅橡胶含量的增加,共混物的硫化速率变慢,力学性能降低,当再生硅橡胶质量分数为46.9%时,共混物的综合力学性能较好。当2,5-双(叔丁基过氧化)-2,5-二甲基己烷用量为0.5份(质量)且沉淀法白炭黑用量为15份时,共混物具有良好的力学性能。机械剪切破碎法没有引起再生硅橡胶化学性质的变化;共混物的玻璃化转变温度与硅橡胶接近,但其损耗因子峰值下降;共混物中填料的分散均匀性介于再生硅橡胶与硅橡胶之间。     

Morphology and properties of poly(vinylidene fluoride)/silicone rubber blends

Blends of poly(vinylidene fluoride) (PVDF) and silicone rubber (SR) were prepared through melt mixing. The morphology, rheology, crystallization behavior, mechanical properties, dynamic mechanical properties and thermal properties of the PVDF/SR blends were investigated. The blend with 9 wt % of SR showed spherical shape of disperse phase whereas the blend with 27 wt % of SR resulted in irregular shape of rubber phase. The rheology showed that the complex viscosity and storage modulus of the blends decreased with increasing the SR content. The mechanical properties of the blends were decreased with increasing the SR content but that were significantly improved after dynamical vulcanization. The crystallization temperature of PVDF phase in PVDF/SR blends was increased. The incorporation of SR improved the thermal stability of PVDF/SR blends, and the temperature at 10% mass loss of the blends increased to about 489°C compared with 478°C of the pure PVDF. The mass of residual char in experiment of the blends was lower than that obtained in theory. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 39945.     

我国氟、硅橡胶工业发展现状及建议

介绍了氟、硅橡胶的性能和应用,对我国氟、硅橡胶工业发展现状进行了概述,提出了存在的问题及发展建议。指出:针对氟橡胶产品品种少、加工手段落后的现状应加大新产品的开发力度;加强应用产品的研究,努力形成配套供货的优势;加强技术服务和技术合作,积极开展应用配方研究。对硅橡胶应开发和建立具有经济规模的生胶及混炼胶装置,开发混炼胶系列品种和高品质品种。     

Dielectric and mechanical properties of polystyrene/acrylonitrile–butadiene rubber blends

The dielectric and mechanical properties of polystyrene(PS)/acrylonitrile–butadiene rubber (NBR) blends were studied with the aim of improving the insulation properties of NBR. Compatibility investigations, performed with viscosity and dielectric methods and confirmed with the calculated heat of mixing, indicated that such blends were incompatible. To overcome the problem of phase separation between NBR and PS, we chose epoxidized soya bean oil to act as a compatibilizer and added 3% to the blends under investigation. This led to the conclusion that a sample containing 10% PS (either pure or scrap) possessed the most suitable electrical and mechanical properties. For this reason, the sample was chosen for studying the effect of the addition of three types of fillers (quartz, talc, and calcium carbonate) in increasing quantities (up to 80 phr) on the dielectric and mechanical properties. The variation of the dielectric properties with temperature (20–60°C) was also investigated. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 540–552, 2002     

Tensile properties and interfacial adhesion of silicone rubber/polyethylene blends by reactive blending

Two‐phase blends of silicone rubber (SR) and linear low density polyethylene (LLDPE) were prepared by reactive blending using peroxide crosslinking agent of SR. The tensile strength and elastic modulus of the SR were found to be increased by reactive blending with LLDPE without sacrifice of the elongation. The improvement of the tensile properties is attributed to the strong adhesion at the interface between SR matrix and LLDPE domain due to the chemical reaction by peroxide. The observation by polarized optical microscopies revealed that the debonding did not occur at the interface, but the LLDPE domains were elongated to longer one. Despite the elongation of the LLDPE domain, the blends exhibited good deformation recoverability. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46192.     

蜂窝结构复合硅橡胶泡沫材料的制备与性能

采用同步硫化技术制备了蜂窝结构理面复合硅橡胶泡沫材料。对材料进行了ＳＥＭ照片分析,并测试了材料的拉伸和压缩应力－应变曲线。结果表明：蜂窝结构硅橡胶泡沫材料内部为大小不等但相互边通的开孔网络结构、泡沫与硅橡胶之间无明显界面;拉伸性能比开孔硅橡胶泡沫材料高得多;压缩性能与开孔硅橡胶泡沫相近。     

硅橡胶/PVPP水凝胶共混型吸水膨胀材料的制备及性能研究

采用共混法制备硅橡胶/聚乙烯基吡咯烷酮(PVPP)水凝胶吸水膨胀材料,研究其吸水膨胀性能和物理性能.试验结果表明,随PVPP水凝胶用量的增大,硅橡胶/PVPP水凝胶复合材料表面亲水性显著提高,体积膨胀率增大,物理性能降低.     

Effect of compatibilizers on the miscibility of natural rubber/silicone rubber blends

In this study, the blending system of natural rubber (NR) and silicone rubber (SR) at 70/30 ratio was investigated. Two kinds of graft polymers, polysiloxane‐g‐octane with different grafted ratios (polymers A, B, and C) and polysiloxane‐g‐(3,7‐dimethyl‐6‐octylene) (polymer D), were designed and synthesized to serve as compatibilizers. Dynamic mechanical analysis and scanning electron microscopy analyses showed that the compatibilizers improved the compatibility between NR and SR, and resulted in improved mechanical properties. For example, the tensile strength of the blends with compatibilizer C was 11.7 MPa, whereas that of the blends without any compatibilizer was only 7.86 MPa. The larger the grafted ratios, the better the compatibilization effect of the graft polymer. The differences in compatibilization effects between non‐reactive (polysiloxane‐g‐octane) and reactive [polysiloxane‐g‐(3,7‐dimethyl‐6‐octylene)] compatibilizers can be attributed to their different chemical compositions. The crosslink density obtained from solid‐state nuclear magnetic resonance indicated that the reactive compatibilizer (polymer D) engaged in the crosslink reaction through the active vinyl at the side chains, which effectively inhibited the decreasing trend of the crosslink density caused by the addition of compatibilizers. POLYM. ENG. SCI., 54:355–363, 2014. © 2013 Society of Plastics Engineers     

Recycling of silicone rubber waste: Effect of ground silicone rubber vulcanizate powder on the properties of silicone rubber

The silicone rubber vulcanizate powder (SVP) obtained from silicone rubber by mechanical grinding exists in a highly aggregated state. The particle size distribution of SVP is broad, ranging from 2 µm to 110 µm with an average particle size of 33 µm. X‐ray Photoelectron Spectroscopy (XPS) and Infrared (IR) Spectroscopy studies show that there is no chemical change on the rubber surface following mechanical grinding of the heat‐aged (200°C/10 days) silicone rubber vulcanizate. Addition of SVP in silicone rubber increases the Mooney viscosity, Mooney scorch time, shear viscosity and activation energy for viscous flow. Measurement of curing characteristics reveals that incorporation of SVP into the virgin silicone rubber causes an increase in minimum torque, but marginal decrease in maximum torque and rate constant of curing. However, the activation energy of curing shows an increasing trend with increasing loading of SVP. Expectedly, incorporation of SVP does not alter the glass‐rubber transition and cold crystallization temperatures of silicone rubber, as observed in the dynamic mechanical spectra. It is further observed that on incorporation of even a high loading of SVP (i.e., 60 phr), the tensile and tear strength of the silicone rubber are decreased by only about 20%, and modulus dropped by 15%, while the hardness, tension set and hysteresis loss undergo marginal changes and compression stress‐relaxation is not significantly changed. Atomic Force Microscopy studies reveal that incorporation of SVP into silicone rubber does not cause significant changes in the surface morphology.