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溶胶-凝胶-硫化法制备硅橡胶吸附萃取搅拌棒 总被引:1,自引:1,他引:0
采用溶胶-凝胶-硫化法,以甲基乙烯基硅橡胶和乙烯基封端硅橡胶为原料制备了厚壁硅橡胶吸附萃取搅拌棒(stir bar for sorptive extraction,SBSE)。采用分段硫化和多阶程序升温老化防止涂层脱落和龟裂,一次涂渍涂层厚度约150~250μm,280℃下无流失,使用寿命可达150次。利用所制备涂层,结合自制热解析系统(thermal desorption system,TDS),建立了SBSE-TDS-CGC-FID测定水样中6种多环芳烃(polyaromatichydrocarbons,PAHs)的方法。方法的线性范围为0.3~1000μg/L,检出限为0.002~0.011μg/L,相对标准偏差在0.92%~6.14%之间。该方法能够满足欧盟2005/69/EC指令对多环芳烃低于10 mg/kg的检测要求。 相似文献
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以十三氟辛基三乙氧基硅烷、四甲基二乙烯硅氧烷、乙烯基三甲氧基硅烷和正硅酸乙酯为原料,通过水解缩合制备了乙烯基含氟硅树脂。乙烯基硅橡胶和乙烯基含氟硅树脂为基质材料,含氢硅油为交联剂,硅氢加成制备了改性硅橡胶杂化膜材料。透气性能测试表明,当含氟硅树脂质量分数50.0%时,膜的成膜性和富氧性能之间达到最佳平衡点,30℃和0.01 MPa压差下,P(O2)为628 Barre,a(O2/N2)为3.36。与普通乙烯基硅橡胶交联膜比,这种有机―无机杂化膜在保持原有氧气透过系数的基础上,较好的改进了氧氮分离性能。 相似文献
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基于考虑了悬垂链的橡胶弹性统计模型,通过引入应变放大因子,建立了硅橡胶纳米复合材料的基于微观机制的本构关系,其中利用硅橡胶分子信息(分子量M、乙烯基含量wt_(Vi)%)、乙烯基反应程度(q)估算获得本构方程中的交联点间链段分子量(Mc),网络链(network strands)体积分数(Φ)等参数,通过拟合确定了与纳米粒子相关的部分参数(初始应变放大因子X_0,极限应变放大因子X_∞,衰减因子z),对掺杂白炭黑的单组分及长短链配合硅橡胶拉伸应力-应变数据进行拟合,在采用相同X_∞,z值情形下,拟合曲线仍能与实测值符合较好(拟合的Adj.R-Square值分别为0.99576、0.99596)。基于微观物理机制的本构关系能够成为联系微观分子结构参数与宏观应力的桥梁,本文工作有望为更有针对性地改进和优化硅橡胶的性能提供依据。 相似文献
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采用填加SiO_2增强的甲基乙烯基硅橡胶混炼压片。通过~(60)Co-γ射线引发辐射硫化,利用共辐照方法,将N-乙烯基吡咯烷酮接枝到该硅橡胶上,制备了高纯度医用水凝胶。本文较系统地研究了接枝单体浓度、辐照剂量率、剂量、温度和接枝试片厚度等因素对接枝共聚反应的影响。建立了接枝速率与单体浓度、剂量率之间的动力学关系式:R_g=k[M]~(4/5)D~(1/2)。讨论了反应机制和接枝区域。 相似文献
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加成型液体硅橡胶的研究进展 总被引:1,自引:0,他引:1
结合加成型液体硅橡胶的硫化原理,综述了加成型液体硅橡胶导热性能、耐高温性能及粘结性能的最新研究进展,发现加入金属氮化物导热填料是提高加成型液体硅橡胶导热性能的有效途径;改善分子结构是提高加成型液体硅橡胶耐高温性能的主要途径;共混粘结促进剂是提高加成型液体硅橡胶粘结性能的重要途径。介绍了加成型液体硅橡胶的最新应用领域,提出功能化加成型液体硅橡胶,如3D个性化打印硅橡胶、人体器官硅橡胶、高折光封装硅橡胶等功能材料是未来加成型液体硅橡胶的发展方向。 相似文献
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The present study investigated the effects of two types of natural rubber and different blend ratios on the cure, tensile properties and morphology of natural rubber/recycled chloroprene rubber blends. The blends of natural rubber/recycled chloroprene rubber were prepared by using laboratory two-roll mill. The result showed that the cure time prolonged with the addition of recycled chloroprene rubber (rCR). Comparability, natural rubber/recycled chloroprene rubber (SMR L/rCR) blendcured rapidly than epoxidized natural rubber/recycled chloroprene rubber (ENR 50/rCR) blend. The addition of rCRalso caused a decrement in the tensile strength and elongation at break for both rubber blends. The SMR L/rCR blendsshowed higher tensile strength and elongation at break compared to those of ENR 50/rCR blends at any blend ratios. 相似文献
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As environmental regulations are getting stricter, tire industries for automobiles have shown much interest in substituting silica for conventional carbon black partially or entirely. To take full advantage of silica as fillers for rubbers, it is essential to find a reasonable rubber system that shows an excellent performance with silica reinforcement. Therefore, in this study, several different rubber compounds comprising the same amount of silica were prepared with several different rubber systems, respectively. The processability, curing characteristics, and mechanical and viscoelastic properties of the rubber compounds were investigated to analyze the performance of the rubber compounds as tire tread materials. Among the rubber compounds studied, SBR1721 compound comprising natural rubber (NR) and styrene butadiene rubber (SBR) with high styrene content was considered the most appropriate for application to tire tread materials. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献
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Analytical method for determination of the bound rubber composition of a filled SBR/BR blend compound was developed using measurement of the bound rubber content and microstructural analysis of the unbound rubber composition. Various filled SBR/BR blend compounds with different blend ratios were prepared using SBRs with different microstructures. This method included measurement of the bound rubber content, extraction of the unbound rubber, microstructural analysis of the unbound rubber composition, and process for determination of the bound rubber composition. Composition of the unbound rubber was analyzed using liquid proton nuclear magnetic resonance spectroscopy (H-NMR) and transmission Fourier transform infrared spectroscopy (FTIR). It was found that the analytical results using H-NMR had less experimental errors than those using transmission-FTIR. The raw SBR/BR blends were also analyzed in order to evaluate level of the experimental errors. Average SBR/BR ratios of the unbound rubbers were obtained using the 1,2- and 1,4-unit contents determined by the H-NMR analysis. The bound rubber compositions were obtained using the bound rubber contents and the average unbound rubber compositions. It was found that most of the bound rubbers had higher SBR ratios than the formulation value. 相似文献
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Haijing Wang Xiuli Fan Hong Yu Jiayang Li Xia Cui Xia Xu 《Journal of separation science》2023,46(19):2201041
Taraxacum kok-saghyz Rodin (TKS) has abundant natural rubber in its root and the molecular weight of its natural rubber is higher than that in Hevea brasiliensis. Thus, TKS is an excellent alternative for the commercial production of natural rubber. The content and molecular weight of natural rubber are two qualitative indicators. Efficient determination for both indicators is still a challenge. In this study, we developed a method to simultaneously determine the content and molecular weight of natural rubber in TKS with pyrolysis-gas chromatography-mass spectrometry. The content of natural rubber was quantified by internal standard method. We optimized the pyrolysis temperature and chromatographic method during content determination. The limits of detection and quantification were 0.47 and 1.56 μg, respectively. In addition, the arachidonic acid methyl ester, an unsaturated fatty acid proposed from the α-end group of natural rubber, was quantified to obtain the number of natural rubber polymers. Based on the content and the polymer number, we also quantified the molecular weight of natural rubber. Thus, the content and molecular weight of natural rubber were simultaneously determined in TKS. Our study provides a new perspective for the high throughput analysis of natural rubber. 相似文献
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N.C. Dafader M.E. Haque F. Akhtar 《高分子科学》2005,(5):497-501
The effect of storage on physico-chemical properties of non-irradiated natural rubber and radiation vulcanized natural rubber (RVNR) were evaluated. The rubber films were stored under two different conditions, namely in open air and sealed polyethylene bags. The antioxidant, tris(nonylated phenyl) phosphite (TNPP) was used for preventing degradation of RVNR films. Gel content, cross-link density, tensile strength at break and 500% elongation of rubber films were measured. The results show that the retention (%) of tensile properties of rubber films with TNPP is higher than that of rubber films without antioxidants. The rubber films stored in polyethylene bags also show better retention of tensile properties than those of rubber films stored in open air. 相似文献
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根据作者已建立的准网络形态模型和推导出的基体层厚度计算公式,从实验上研究了橡胶粒子的分布对聚氯乙烯(PVC)/丁氰橡胶(NBR)共混物脆韧转变的影响.结果表明,不仅无规形态PVC/NBR共混物存在脆韧转变主曲线,而且准网络形态PVC/NBR共混物也存在脆韧转变主曲线.但是两条主曲线明显不重合,表明橡胶粒子的分布对PVC/NBR共混物脆韧转变有显著影响.而且准网络形态PVC/NBR共混物的临界基体层厚度比无规形态PVC/NBR共混物的临界基体层厚度大得多,表明准网络形态比无规形态明显有利于增韧.因此临界基体层厚度不仅是基体的特征参数,还是界面粘结和橡胶粒子分布的函数. 相似文献
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高密度燃料HDF-1与橡胶的相容性研究 总被引:3,自引:0,他引:3
报道了在室温和70 ℃下橡胶材料G402氟硅胶、丁腈胶5171、丁腈胶4170、贮囊橡胶用合成的高密度燃料HDF-1浸泡后性能如伸长率、邵尔硬度、重量、面积体积的变化,并与采用3号喷气燃料(RP-3)实验结果进行对照。用红外光谱测定了燃料浸泡前后橡胶组成的变化。实验结果表明,G402氟硅胶和贮囊对于HDF-1和RP-3有相近的相容性,丁腈胶5171对HDF-1的相容性比对RP-3的相容性稍差,丁腈胶4170对HDF-1的相容性比对RP-3的相容性更差的结果。因此,丁腈胶5171和丁腈胶4170不能用于HDF-1储存和输送,原使用RP-3系统的橡胶密封件不能直接使用HDF-1。 相似文献