基于乘用车轮胎胎面胶粉的再生橡胶的制备及性能

通过力化学再生法制备了以废轮胎胶粉为原料的再生橡胶，研究了不同活化剂420用量对再生橡胶性能的影响，测试表明：再生橡胶含硫键断裂生成了硫自由基，随着活化剂含量的增加，再生橡胶的邵氏硬度和交联密度持续降低；拉伸强度、断裂延伸率和凝胶含量均先升高后降低，在活化剂用量为0.9 phr时，拉伸强度和断裂延伸率最大，再生橡胶的凝胶含量最大为19.7%。 微观形貌发现，废轮胎胎面胶粉的颗粒较为分散，再生橡胶的结构颗粒相互粘连，孔洞和缺陷较多，再生橡胶的门尼黏度随着活化剂含量的增加而降低。 综合来看，活化剂420的最佳含量为0.9 phr，再生橡胶各项性能最优。     

橡胶疲劳失效影响因素及提升策略

橡胶在使用过程中会承受一定载荷从而导致疲劳失效,其失效源于裂纹扩展且最终可能导致材料完全断裂。本文对橡胶耐疲劳性能通用研究方法、橡胶疲劳破坏机理进行总结,并综述了机械载荷历史、填料、动态键、环境等因素对橡胶疲劳性能的影响,最后对橡胶疲劳研究面临的挑战和发展方向进行了展望。     

轮胎胎面胶料性能及其机理研究进展

滚动阻力、抗湿滑性能和耐磨性能是轮胎使用过程中最重要的三项性能,然而它们之间存在着严重的相互制约关系,同时提高这三项性能对胎面材料研发仍是一个挑战。本文从橡胶复合材料黏弹性的角度,综述了填料网络结构、填料-橡胶相互作用等对胎面胶料的滚动阻力、抗湿滑性能、耐磨性能的影响及其机理研究进展。通过橡胶分子结构优化以及填料改性,降低胶料中的填料网络结构,提高填料-橡胶相互作用,有利于提高胎面胶料的综合性能。     

石墨烯/橡胶纳米复合材料研究进展

石墨烯结合了碳纳米管导电和黏土片层的结构特征,为发展高性能、多功能聚合物纳米复合材料提供了新的方向.石墨烯/橡胶纳米复合材料近年来引起广泛关注.众多研究结果表明石墨烯是橡胶的理想填料之一,为高性能橡胶改性提供了新途径.本文介绍了石墨烯/橡胶纳米复合材料的3种主要制备方法,即乳液共混法、溶液共混法和机械混炼法,以及材料的物理机械性能、电学性能、气体阻隔性能和热学性能,并分析了该类材料的发展前景和存在问题.     

双烯类液体橡胶的研发进展

液体橡胶作为合成橡胶的重要种类,是室温下能流动的橡胶材料。本文介绍了液体橡胶的性能特点及分类,着重阐述了双烯类液体橡胶即液体聚丁二烯橡胶、液体丁腈橡胶、液体异戊橡胶、液体丁苯橡胶和液体氯丁橡胶的结构特征、性能特点及主要用途,并进一步探讨了它们的研发、生产和使用情况。液体橡胶便于实现生产连续化和自动化,且加工方便,顺应时代发展的"低碳"潮流。从产品种类、牌号,应用范围等方面对今后的发展提出了建议。     

聚硫橡胶和环氧树脂互穿网络和共聚网络

本文以丙烯酸酯封端的聚硫橡胶，环氧封端的聚硫橡胶分别同双酚环氧树脂合成互穿网络和共聚网络，并研究了它们的相结构和性能。结果表明，所有样品都具有低温柔性和良好的力学性。     

橡胶补强填料的研究进展

随着汽车行业的发展,在"安全、环保和节能"方面,对轮胎的性能提出了更高的要求,因此对轮胎原料—橡胶的补强研究越来越多。本文详细介绍了补强填料补强橡胶的机理、补强填料的分类及改性途径,概述了传统补强填料炭黑、白炭黑及炭黑/白炭黑双向填料的性能和研究现状,综述了新型补强填料硅酸盐类、碳酸盐类及其它常用新型种类和性能,指出新型填料拓展了橡胶补强技术和功能橡胶材料领域的研究思路,应加强橡胶补强填料的开发、补强机理探讨和拓展补强复合材料的表征和检测手段,以满足橡胶行业发展的需求。     

橡胶增韧塑料机理

综述了橡胶增韧塑料机理研究的发展与现状,着重探讨了橡增韧机理中有关脆韧转变的定量研究,同时也讨论了分散相的形态参数、界面相容性和韧性测试条件以及分散相与基体的性能等因素对橡胶增韧塑料性能及增韧的影响,最后提出了橡胶增韧塑料研究的发展趋势。     

橡胶硫化促进剂的研究进展

作为橡胶加工成形过程中最重要的步骤之一,橡胶硫化直接影响橡胶制品的性能。与单用硫黄相比,少量的促进剂与硫磺配合可以极大地提高硫化速率,改善硫化胶的性能。但目前橡胶硫化促进剂普遍具有潜在的人类健康和环境风险问题,同时硫化促进效能较低、功能单一。因此,开发无毒、无或少氧化锌、高效、多功能的新型硫化促进剂对橡胶工业具有非常重要的意义。本文首先简要介绍了橡胶硫化促进剂的发展历程,然后综述了近年来新型橡胶硫化促进剂的研究进展(包括离子液体促进剂、新型二硫代氨基甲酸盐类促进剂、稀土促进剂、以及含新型副促进剂的硫化并用体系等),并对橡胶硫化促进机理、新型橡胶硫化促进剂的设计进行了展望。     

湿法改性石墨烯在制备橡胶复合材料中的应用

橡胶由于其高弹性、良好的生物相容性、耐化学腐蚀及长期使用的稳定性等优点,在众多领域已有一百多年的应用历史。一般来说,在生胶硫化之前需要加入增强填料、润滑剂、偶联剂和促进剂等各类添加剂,以达到使用要求的性能。其中增强填料起到提高橡胶强度、提高橡胶耐磨耐热性、延长橡胶使用寿命的作用。相比于炭黑或者二氧化硅这些传统增强填料,新兴纳米材料石墨烯由于其优异的性能,只需极少量便可使橡胶的性能显著增强。然而,石墨烯片层之间的范德华力严重的阻碍了其在高分子机体内的分散,其在橡胶基体的分散性直接决定了石墨烯对于橡胶材料的增强效果。近年来,越来越多的研究开始关注通过在溶液中的湿法改性,包括物理或化学的方法来改性石墨烯,促进它与橡胶二者界面的相互作用,提高石墨烯在橡胶基体中的分散效果。本文总结了近几年湿法改性石墨烯在制备石墨烯/橡胶复合材料方面的研究进展。     

漫谈高分子物理学的源起和发展

以漫谈方式简要回顾了高分子物理学的源起和发展历程,提出了以橡胶弹性理论作为高分子物理学发展源头的观点,揭示了高分子物理学中一些占主导地位的理论能取得成功的内在原因,以期为今后该学科的发展提供一些有益的启迪.     

Qualitative and Quantitative Determination of The Polymer Content in Rubber Formulations

The objective of this paper is to show an easy and rapid way to determine qualitatively and quantitatively the type of polymer or polymer blend used in a rubber formulation. The most common polymers used manufacturing rubber products were tested and characterized by both their decomposition temperature and the curve profile. Thermogravimetric analysis, which is considered to be used mainly for quantitative purposes, turned out to be a rather useful analytical tool to obtain qualitative information of such elastomeric mixtures. This revised version was published online in August 2006 with corrections to the Cover Date.     

Radiation-Induced Conductivity of Polymer Composites Filled by Finely Divided Oxides

The radiation-induced conductivity of polymer composites based on polyisoprene rubber filled with finely divided oxides of various chemical natures was studied in the continuous irradiation mode. It was shown that the radiation conductivity is closely related to the molecular mobility of the rubber. It was found that a change in the character of thermal motion of fragments of rubber macromolecules, which is caused by interaction with the filler, could considerably enhance the radiation-induced conductivity of a polymer composite.     

Dispersing behavior of recycled rubber particles

The hydrophobic nature of recycled rubber particles presently limits their use only in non-aqueous media. Recycled rubber particles were chemically modified by preparation of amphiphilic semi-interpenetrating polymer networks using poly(acrylic acid) as the hydrophilic polymer. The resulting composite particles are water dispersible and suitable for various aqueous media applications.     

Heterogeneous polymer systems. IV. Mechanism of rubber particle formation in rubber-modified vinyl polymers

A mechanism for the formation of rubber particles in the polymerization of solutions of rubber in vinyl monomers is presented. A polymeric oil-in-oil emulsion is formed in the first phase of the polymerization. This polymeric oil-in-oil emulsion is transtormed into a solid dispersion of rubber in vinyl polymer in the second phase of the polymerization. A phase inversion takes place in the emulsion in the first phase of the polymerization. Rubber solution droplets are formed at the phase inversion point. These droplets harden as the polymerization proceeds and are gradually transformed into the solid, crosslinked rubber particles of the final polymer.     

Development of a rubber elongation factor, surface-imprinted polymer-quartz crystal microbalance sensor, for quantitative determination of Hev b1 rubber latex allergens present in natural rubber latex products

Molecularly imprinted polymers (MIPs) for screening to detect rubber latex allergens (Hev b1) in natural rubber based products were designed as artificial recognition polymeric materials coated onto a quartz crystal microbalance (QCM). The polymers were prepared using a stamp imprinting procedure after mixing optimum amounts of methacrylic acid–vinylpyrrolidone–dihydroxyethylene bisacrylamide and Hev b1 latex allergen proteins, obtained from rubber gloves. QCM measurements showed that the resulting polymer layers after removal of the proteins used in their preparation could incorporate structures and features down to nanometer scale of protein templates into the imprinted polymer much better than a non-specific control polymer under controlled sensor conditions and an optimized polymerization process. This selective polymer but not the non-selective polymer clearly distinguished between the latex allergen Hev b1 and proteins such as lysozyme, ovalbumin and bovine serum albumin, with a selectivity factor of from 2 to 4, and the response of the rubber elongation factors by an astonishing factor of 12. The imprinted cavities recognized specific binding sites and could distinguish among related hevein latex allergenic proteins isolated from fresh natural rubber latex; Hev b1, Hev b2, and Hev b3 with a selectivity factor of from 4 to 6. The different QCM measurements obtained presumably reflected slightly different conformations and affinities to the MIP binding sites. The sensor layers selectively adsorbed Hev b1 within minutes in amounts ranging from 10 to 1500 μg L⁻¹ and with a detection limit of 1 μg L⁻¹. This work has demonstrated that this new sensor provides a fast and reliable response to natural rubber latex protein, even after being extracted from the matrix of rubber gloves.     

Features of rubber swelling in transformer oil,according to NMR data

NMR spectroscopy, NMR relaxation, and NMR with a pulsed magnetic field gradient methods are used to study the swelling of the elastomers based on ethylene-propylene rubber, butadiene-nitrile rubber, and fluororubber SKF-26 in transformer oil. Components corresponding to the fractions of oil and polymer network are identified. It is shown that the affinity of the polymers toward transformer oil displays an increase in the orderly sequence of ethylene-propylene rubber, fluororubber, and butadiene-nitrile rubber; the stability of the polymers towards carbon tetrachloride falls in the same sequence. Based on an analysis of the spin–spin relaxation time depending on the degree of swelling, it is found that fluororubber elastomers are characterized by the formation of a polymer network that prevents further sorption, In contrast, elastomer based on ethylene-propylene rubber gives no indication of the formation of a rigid polymer network.     

白炭黑增强型硅橡胶的组成及抗原子氧性能分析

为明确空间级硅橡胶的化学组成及填料添加对材料物理性能的影响, 采用填料复合方式制备硅橡胶高聚物材料, 并通过化学成分测试、 原子氧暴露试验及力学性能测试等研究其结构组成与物理性能. 经微观粒径测试得出硅橡胶中白炭黑填料粒径主要分布在8~16 μm; 经傅里叶变换红外光谱(FTIR)、 核磁共振波谱( ¹H NMR和 ²⁹Si NMR)和溶胶凝胶渗透色谱(GPC)测试得出硅橡胶中含有Si—Me, Si—Ph, Si—O—Si等基团和甲基、 苯基等官能团, 其分子量分散系数为1.56, 并进一步推断出硅橡胶的分子结构及基胶与交联剂的反应类型为脱羟胺型; 经原子氧暴露试验及力学试验证实, 与未改性白炭黑填充的硅橡胶高聚物材料相比, 经硅烷改性白炭黑填充的硅橡胶高聚物材料表现出更好的抗原子氧性能, 动态力学测试后储能模量高54%, 并具有更好的应力应变响应性能. 研究结果表明, 采用表面改性处理方式可增强填料与硅橡胶基质的相互作用, 从而提高填料复合型硅橡胶高聚物材料的抗原子氧性能及综合力学性能.     

Structure-Property Relationships in Rubber-Modified Styrenic Polymers

Styrenic polymers and copolymers are often impact modified with rubber particles. The efficiency of rubber toughening depends mainly on the size of the rubber particles and the degree of cross-linking. The deformation rate, the temperature, the orientation of the polymer molecules and the efficiency of rubber grafting also influence rubber toughening. It is thought that on impact, cavitation inside the rubber particles occurs which reduces the detrimental dilatational stress in the bulk polymer without forming cracks in the brittle matrix or at the rubber-matrix interface. Crazing and shearing are facilitated if the rubber particles can easily cavitate. This can be achieved by either avoiding too much cross-linking or by adding oil (silicone oil in the case of ABS) into the rubber particles, which acts as nuclei for void formation. An electron spectroscopic imaging method is described which allows visualizing the location of the oil. Already after cooling silicone oil modified ABS samples down to liquid nitrogen temperature rubber cavitation is observed. This cavitation is caused by the thermal stress developing due to the differences in thermal expansion coefficient between the rubber phase and the SAN-matrix and is facilitated by silicone oil. Voiding also leads to an increase of light scattering, which can be detected by an optical microscope using dark field illumination.