橡胶-填料相互作用对丁苯橡胶/白炭黑复合材料性能的影响

本文研究了硅烷偶联剂原位改性白炭黑对溶聚丁苯橡胶(SSBR)性能的影响,结果表明,通过哈克转矩流变仪对含有偶联剂的SSBR/白炭黑混炼胶进行原位热处理后可明显减弱混炼胶的Payne效应,改善白炭黑在橡胶基体中的分散.原位热处理方法能够明显提高硫化胶的300%定伸应力,降低动态压缩温升,同时可使硫化胶在0℃附近具有较高的损耗因子(tanδ),60℃附近具有较低的tanδ.对不同聚合方式得到的丁苯橡胶,即溶聚丁苯橡胶与乳聚丁苯橡胶(ESBR)/白炭黑复合材料的力学性能及动态力学性能进行了研究,结果表明,白炭黑在SSBR2305中分散效果优于在ESBR1502中;采用偶联剂原位改性白炭黑可以使SSBR2305硫化胶获得与ESBR1502硫化胶相当的物理机械性能,更理想的动态力学性能,从而得到力学性能、抗湿滑性、滚动阻力及耐磨性更加均衡的理想轮胎材料.通过对具有不同偶联效率的SSBR/白炭黑体系的微观结构与性能研究发现,随偶联效率的增加,其结合橡胶含量增加,Payne效应减弱;高偶联效率的S-SBR具有较低的动态压缩温升及较好的耐磨性.     

一种新型硅藻土填充橡胶纳米复合材料研究

橡胶的填料问题一直是人们的研究热点,针对炭黑和白炭黑在橡胶生产中存在的污染问题,本文选用成分结构与白炭黑类似的硅藻土来填充各种橡胶。首先对硅藻土进行了改性,并对不同改性剂改性硅藻土用于填充橡胶进行了研究。结果表明2.5份偶联剂Si69的改性效果最佳。通过机械共混法制备了改性硅藻土/橡胶纳米复合材料,通过力学性能测试确定了比较适合硅藻土填充的橡胶是氟橡胶、三元乙丙橡胶和丙烯酸酯橡胶。绿色环保且价格低廉的硅藻土可以替代白炭黑增强填充氟橡胶、三元乙丙橡胶和丙烯酸酯橡胶。     

T(4-Mop)PS4卟啉与牛血清蛋白相互作用的研究

以四-(4-甲氧基-3-磺酸基苯)卟啉(T(4-Mop)PS4)为探针,通过T(4-Mop)PS4与牛血清白蛋白(BSA)的相互作用,建立了测定BSA的电化学分析方法。T(4-Mop)PS4的峰电流变化(ΔIp)与BSA在2.0×10-6～1.0×10-5mol.L-1范围内呈良好的线性关系,检出限为1.2×10-6mol.L-1;对5.0×10-6mol.L-1BSA平行测定8次,其相对标准偏差为2.0%,回收率为95%～104%。组氨酸、缬氨酸、苯丙氨酸、丝氨酸、异白氨酸、谷氨酰胺、苏氨酸等氨基酸对BSA的测定不产生干扰。采用紫外可见光度法、荧光光谱法和线性扫描伏安法(LSV)研究了T(4-Mop)PS4与BSA之间的相互作用,并测定了二者相互作用的结合常数和结合比。研究表明,T(4-Mop)PS4与BSA之间主要以疏水作用力结合,形成了1∶1的稳定复合物。     

光谱法研究氧氟沙星-铽络合物与脱氧核糖核酸的相互作用

以氧氟沙星 铽 (Tb3+ )作为荧光探针 ,利用荧光光谱、吸收光谱研究了氧氟沙星 铽 (Tb3+ )络合物与脱氧核糖核酸 (DNA)的相互作用。研究表明 :在实验条件下 ,脱氧核糖核酸能显著增强氧氟沙星 Tb3+ 体系的荧光 ,据此建立了脱氧核糖核酸的测定方法 ,线性范围为 5 .0× 1 0 - 6 ～ 1 .0× 1 0 - 4mol L ;检出限为 1 .7× 1 0 - 6mol L,通过人血清中DNA测定的回收率实验 ,结果令人满意。实验还表明 :氧氟沙星 Tb3+ 探针与DNA分子之间主要是沟槽式结合。     

聚合物复合材料填充剂的表面性质及其分散性的研究

本文通过反气相色谱技术研究了未处理的、硅烷偶联剂处理的和钛酸酯偶联剂处理的三种Al(OH)_3粉末的表面性质,并通过塑化仪和扫描电子显微镜研究了Al(OH)_3填充聚丙烯体系的流变行为及其在聚丙烯中的分散效果.结果表明Al(OH)_3的表面性质对其在聚丙烯介质中的分散效果有着重要的影响.     

Fc-Arg(NO2)-Gly-Asp(OMe)-OMe的合成及其与牛血清白蛋白的相互作用

以二茂铁,Gly,Asp和BOC-Arg(NO2)-OH为原料,采用液相合成法,以HBTU及HOBt为缩合剂合成了二茂铁-肽化合物Fc-Arg(NO2)-Gly-Asp(OMe)-OMe（5）,其收率为38.7%,并对化合物5进行了表征。采用电化学、紫外-可见吸收光谱及荧光光谱等研究了近生理条件下其与牛血清白蛋白(BSA)的相互作用,讨论了其对BSA构象的影响。实验结果表明化合物5与BSA间相互作用为静态猝灭过程,反应结合位点数为0.856,结合常数为1.75×103 L•mol-1,并依据能量转移理论确定了其与BSA相互作用的最近距离为2.14 nm。     

一维C_(36)聚合物的C_(36)分子间的电-声相互作用

在用半经验自洽场晶体轨道方法计算能带结构的基础上，并在平均场近似和形变势理论框架下，研究了四种一维线性 C36聚合物模型的 C36分子间电 声耦合常数及其对超导相变和金属 绝缘体相变的影响 .计算结果表明，一维线性 C36聚合物的 C36分子间电 声耦合常数极小，对超导相变和金属 绝缘体相变的影响可以完全忽略 .     

相变过程对等规聚丙烯/炭黑复合材料中填料网络的影响

采用柔和混合方法制备出炭黑(CB)填充等规聚丙烯(iPP)复合材料,CB在iPP熔体中可以进行团聚而形成填料网络,采用动态流变-电阻同步测试的方法,研究原位结晶-熔融过程对所形成网络的影响.实验结果表明,经历原位结晶-熔融后复合材料中可以被动态流变实验检测到的填料网络消失,这是由于结晶和熔融过程中都会影响填料网络结构,而熔融过程中网络的破坏更为显著.相变后网络的重建过程说明,相变过程不能完全破坏熔体中形成的团聚结构,填料网络容易重新形成.     

加工工艺对炭黑填充聚合物双基体复合材料导电性能的影响

制备了炭黑(CB)填充高密度聚乙烯(HDPE)/乙烯-醋酸乙烯酯共聚物(EVA)双基体复合材料,研究了加料顺序、混合时间对复合材料导电性能的影响.结果表明,CB主要分布在HDPE相中;采用CB首先填充EVA然后与HDPE混合,或采用EVA/HDPE共混物与CB混合的加工策略,均可获得导电性较优的导电复合材料.然而,混合过程显著影响CB填充双基体复合材料的导电性.采用EVA/HDPE共混物与CB混合法加工复合材料,导电性受相形态演化影响较小.     

偶极-偶极相互作用的探讨(Ⅱ)

增强拉曼光谱和红外光谱是研究金属电极上吸附分子间振动相互作用的有力工具．分子间的振动相互作用主要通过它们的偶极场，吸附分子吸附峰强度的转移与它们的电子极化率的屏蔽作用密切相关·相关势近似（CoherentPotentialApprokimation，CPA）已广泛用于讨论分子间的振动相互     

Insights into the Payne Effect of Carbon Black Filled Styrene-butadiene Rubber Compounds

As a widely used reinforcing filler of rubber, carbon black(CB) often enhances the nonlinear Payne effect and its mechanism still remains controversial. We adopt simultaneous measurement of rheological and electrical behaviors for styrene-butadiene rubber(SBR)/CB compounds and CB gel(CBG) during large deformation/recovery to investigate the contribution of conductive CB network evolution to the Payne effect of the compounds. In the highly filled compounds, the frequency dependence of their strain softening behavior is much more remarkable than that of their CB network breakdown during loading, while during unloading the unrecoverable filler network hardly affects the complete recovery of modulus, both revealing that their Payne effect should be dominated by the disentanglement of SBR matrix. Furthermore,the bound rubber adjacent to CB particles can accelerate the reconstruction of continuous CB network and improve the reversibility of Payne effect. This may provide new insights into the effect of filler network, bound rubber, and free rubber on the Payne effect of CB filled SBR compounds.     

Filler-polymer interactions in filled polybutadiene compounds

Bound rubber in a filled rubber compound is formed by physical adsorption and chemisorption between the rubber and filler. Polybutadiene (PB) is composed of three components of 1,2-, cis-1,4-, and trans-1,4-units. Filler-polymer interactions in PB compounds filled with carbon black or silica were studied by analyzing microstructures of the bound rubbers with pyrolysis-gas chromatography. Differences in the filler-polymer interactions of the 1,2-, cis-1,4-, and trans-1,4-units were investigated. The filler-polymer interaction of the 1,2-unit is stronger than those of the cis-1,4- and trans-1,4-units. The interaction of the 1,2-unit with silica is stronger than with carbon black. Bound rubber content is decreased by treatment with ammonia. Change of the bound rubber composition after the ammonia treatment was also studied.     

Mechanical Properties of Silicon Carbon Black Filled Natural Rubber Elastomer

A pyrolyzed ash containing about 50% carbon,named silicon carbon black(SiCB),was prepared by the anoxic pyrolysis of rice husk.Fourier transform infrared spectroscopy(FTIR),thermogravimetric analysis(TGA), Brunauer-Enunett-Teller(BET),transmission electron microscopy(TEM)and universal material testing machine were used to analyze the stress-strain relationship,Mullins effect and static viscoelastic properties of SiCB-filled vulcanized natural rubber(NR),and SiCB was compared with a commercially available semi-reinforcing fumace(SRF) carbon black.The results show that the vulcanized natural rubber filled with SiCB had similar reinforcing properties to those of that filled with traditional SRF,but obvious differences between them exist in stress-strain properties and stress softening resistance.We tried to discuss the related phenomena with the aid of the modified two-layer theory. And it is successfully predicted and verified that SiCB has good compression resistance and obvious stress relaxation advantages in compression stress relaxation.     

Influence of Liquid Isoprene Rubber on Strain Softening of Carbon Black Filled Isoprene Rubber Nanocomposites

The reinforcement of rubbers by nanoparticles is always accompanied with enhanced dissipation of mechanical energy upon large deformations. Methods for solving the contradiction between improving reinforcement and reducing energy dissipation for rubber nanocomposites have not been well developed. Herein carbon black(CB) filled isoprene rubber(IR)/liquid isoprene rubber(LR) blend nanocomposites with similar crosslink density(ν_e) are prepared and influence of LR on the strain softening ...     

炭黑填充聚苯乙烯熔体流变行为

研究了炭黑(CB)填充聚苯乙烯(PS)熔体的稳态和动态流变行为. CB/PS复合体系在CB体积分数φ=0.06时发生逾渗转变. 结果表明, 低应变区熔体模量降低主要归因于粒子-粒子及粒子-高分子间作用力的破坏, 高应变下模量的急剧下降则主要与高分子链间解缠结有关. 采用“两相”模型拟合线性动态流变行为, 发现应变放大因子A_f(φ)、填充相模量及松弛指数与温度有关. A_f(φ)~φ关系符合Guth方程和扩散控制的粒子簇聚集模型. “粒子相”形状参数与聚集体分维度均随温度升高而有所降低, 说明CB粒子聚集体因团聚而趋于各向同性, 应变放大效应减弱. “粒子相”特征模量G'_f1(φ)和G"_f0(φ)与φ关系满足标度律. 当φ > 0.06时, G'_f1(φ)和G"_f0(φ)及其标度指数均随温度升高而明显降低, 其G'_f1(φ)变化幅度略大于G"_f0(φ), 说明“粒子相”弹性与黏性组分具有不同的温度依赖性. 随着温度升高, 扩散控制的CB粒子团聚过程加快, 应变放大效应减弱.     

白炭黑填充羧基丁苯橡胶的多层次微观结构研究

分别采用悬浮液吸附混合法、胶乳混合并开炼法制备填充份数0~300 phr、0~60 phr的羧基丁苯橡胶/白炭黑(XSBR/A200)复合物,采用温度调制示差扫描量热法(TMDSC)研究复合物的玻璃化转变行为,采用动态流变法研究A200的补强机理.TMDSC测试结果显示,粒子表面玻璃化层含量与填充份数呈线性关系,且与混合方式无关.流变与TMDSC测试结果对比显示,A200粒子表面存在两层分子能动性不同的受限层,其中玻璃化层内层不能发生玻璃化转变,受限外层可发生玻璃化转变,但在高频下呈刚性行为.根据等价球形模型,在半径为6.8 nm的A200粒子表面,玻璃化层与受限外层厚度分别为1.0和1.6 nm.     

乙烯类聚合物-炭黑复合物的PTC效应

本文以低密度聚乙烯(LDPE)和乙烯-醋酸乙烯酯共聚物(EVA)为基材,炭黑(CB)为导电微粒,探讨了聚合物-炭黑复合物的结构对正温度系数效应(PTC)增强与减弱的影响和炭黑含量与PTC效应的关系以及交联结构对PTC现象的稳定作用.     

CSF纳米炭黑硫化橡胶的性能

天然橡胶;丁苯橡胶;丁腈橡胶;硫化;气密性;导电性;CSF纳米炭黑硫化橡胶的性能     

Nonlinear rheological behavior of silica filled solution‐polymerized styrene butadiene rubber

The reinforcement and nonlinear viscoelastic behavior have been investigated for silica (SiO₂) filled solution‐polymerized styrene butadiene rubber (SSBR). Experimental results reveal that the nonlinear viscoelastic behavior of the filled rubber is similar to that of unfilled SSBR, which is inconsistent with the general concept that this characteristic comes from the breakdown and reformation of the filler network. It is interesting that the curves of either dynamic storage modulus (G′) or loss tangent (tan δ) versus strain amplitude (γ) for the filled rubber can be superposed, respectively, on those for the unfilled one, suggesting that the primary mechanism for the Payne effect is mainly involved in the nature of the entanglement network in rubbery matrix. It is believed there exists a cooperation between the breakdown and reformation of the filler network and the molecular disentanglement, resulting in enhancing the Payne effect and improving the mechanical hysteresis at high strain amplitudes. Moreover, the vertical and the horizontal shift factors for constructing the master curves could be well understood on the basis of the reinforcement factor f(φ) and the strain amplification factor A(φ), respectively. The surface modification of SiO₂ causes a decrease in f(φ), which is ascribed to weakeness of the filler–filler interaction and improvement of the filler dispersion. However, the surface nature of SiO₂ hardly affects A(φ). © 2007 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 2594‐2602, 2007     

改性炭黑及其增强橡胶的研究

从炭黑在橡胶中的应用出发,介绍了炭黑的结构、各种炭黑改性的方法以及改性炭黑对橡胶物理机械性能的影响。