国内外乙丙橡胶生产技术现状及发展趋势

乙丙橡胶是合成橡胶中发展最快的品种之一,由于其具有卓越的耐候性、耐臭氧性和电绝缘性等特性,广泛应用于汽车部件、电线电缆等方面。主要介绍了国内外乙丙橡胶的生产情况及技术现状,并论述了未来乙丙橡胶的生产技术发展趋势。     

三元乙丙橡胶耐磨性能研究

研究了生胶品种、硫化体系、填充体系和加工助剂等因素对三元乙丙橡胶耐磨性能的影响。实验结果表明:胶种选用高乙烯含量,高门尼粘度的非充油型乙丙橡胶,硫化体系采用硫磺/硫载体并用的有效硫磺硫化体系,填充体系采用高结构炭黑N220以及Si-69改性过的气相法白炭黑AS-200并用体系,同时配合0.5份左右的爽滑粉,都能有效提高EPDM胶料的耐磨性能。     

乙丙橡胶新产品开发

介绍了乙丙橡胶生产方法,国内乙丙橡胶生产工艺,吉林石化乙丙橡胶应用情况,吉林石化润滑油系列乙丙橡胶J-0010和密封条系列乙丙橡胶J-4090的研究开发过程及内容。     

对乙丙橡胶生产工艺的几点探究

<正>乙丙橡胶(EPR)是继Zieg1er-Natta催化剂的发明、聚乙烯和聚丙烯的出现后问世的一种以乙烯。丙烯为基本单体的共聚橡胶,分为二元乙丙橡胶(EPM)和三元乙丙橡胶(EPDM)两大类。前者是乙烯和丙烯的共聚物;后者是乙烯、丙烯和少量非共轭二烯烃的共聚物。EPR具有许多其它通用合成橡胶所不具备的优异性能,加之单体价廉易得,用途广泛。目前,     

乙丙橡胶在碱液中界面老化的初步研究

采用表面粗糙度测试、傅里叶变换红外光谱(FTIR)和X射线光电子能谱仪(XPS)等方法研究了在碱液环境中乙丙橡胶表面老化前后的变化规律。结果表明,随着老化时间的延长,橡胶表面粗糙度逐渐增大。XPS测试结果表明乙丙橡胶表面C-C含量降低,而C=O和O=C-O含量增加,这是乙丙橡胶老化的标志。老化后乙丙橡胶的FTIR测试结果表明,在1742cm-1和1162cm-1处对应于C=O和C-O-C的伸缩振动,进一步证实了XPS的结果。     

亚临界流体与高剪切应力对EPDM废胶粉脱硫反应的影响

在废旧三元乙丙橡胶粉(WEPDM)与未硫化三元乙丙橡胶(EPDM)混合物的熔融挤出过程中,采用改变亚临界流体品种和提高双螺杆挤出机螺杆转速的方法,研究了亚临界流体品种与高剪切应力对脱硫共混物DEPDM/EPDM的凝胶含量、门尼黏度、溶胶红外光谱及脱硫共混物共混三元乙丙橡胶与原EPDM共混再硫化材料EPDM/(DEPDM/EPDM)力学性能的影响,对再硫化材料的试样断面形貌也进行了扫描电镜观察。结果表明,亚临界流体水或醇的存在均能促进脱硫、解交联反应的进行,特别是在以亚临界乙醇水(7∶3)混合物作为反应介质的条件下,脱硫反应中交联S-S键断裂选择性明显增大,所得产物凝胶含量降低,门尼黏度增大,其再硫化材料力学性能也明显增加。挤出机的螺杆转速和脱硫反应温度均存在最佳值(220℃,600~800 r/min)。在以醇水混合物为反应介质的最佳条件下(220℃,600~800 r/min),其脱硫共混物共混EPDM再硫化材料EPDM/(DEPDM/EPDM)的拉伸强度和断裂生长率分别达到26.7 MPa和606.3%。     

特种弹性体应用将增长

特种弹性体应用将增长据Ｆｒｅｅｄｏｎｉａ集团公司预测，受轻型车辆生产走出１９９１年低谷复苏的影响，到１９９６年世界特种弹性体生产每年将以３．３％的速度增长。预计总的增长速度要比轻型车辆的增长速度慢，这是由于“大品种”特种弹性体──包括乙丙橡胶、丁基橡...     

乙丙橡胶生产技术发展趋势及市场分析

介绍了乙丙橡胶(EPR)生产技术的最新发展趋势及进展,分析了国内外乙丙橡胶的生产消费现状及发展前景。2009年世界乙丙橡胶的总生产能力约为127.7万t,总消费量约为115.0万t。预计2014年总消费量将达到135.0万t。2009年,我国乙丙橡胶的总生产能力为2.0万t,消费量为19.0万t,预计到2014年总消费量将达到约24.0万t。针对我国乙丙橡胶的生产状况及未来发展所面临的挑战,提出了今后的发展对策。     

正辛基三乙氧基硅烷对白炭黑补强三元乙丙橡胶材料的影响

研究了正辛基三乙氧基硅烷、乙二醇对白炭黑填充三元乙丙橡胶的力学性能、硫化特性的影响,以及压缩蠕变特性与动态力学性能的影响。研究结果表明:添加正辛基三乙氧基硅烷可改善三元乙丙橡胶的蠕变性、降低压缩永久变形。随着硅烷用量的增加,三元乙丙橡胶的蠕变、压缩永久变形有所减小,在用量4~5份时效果较好。硅烷用量增加,使白炭黑填充三元乙丙橡胶的玻璃化转变温度上升、损耗因子增加。正辛基三乙氧基硅烷在EPDM/白炭黑中的效果优于KH-550和KH-792硅烷。     

三聚氰胺氰尿酸盐/红磷/FR600协同阻燃乙丙橡胶的研究

采用垂直燃烧仪、氧指数仪、马弗炉和烟密度箱对三聚氰胺氰尿酸盐(MCA)、红磷及成碳剂FR 600协同阻燃乙丙橡胶的阻燃性能进行了分析表征。研究结果表明,MCA、红磷及FR 600有显著的协同阻燃效应。与MCA阻燃乙丙橡胶相比,红磷和FR 600的加入可以提高体系的成碳率,使得碳层更紧密,乙丙橡胶的氧指数和垂直燃烧等级得到提高。FR 600可以有效降低乙丙橡胶的烟密度。MCA、红磷及成碳剂FR 600的最佳质量配合比分别为84∶24∶12。     

The mechanical properties of ternary composites of polypropylene with inorganic fillers and elastomer inclusions

The effect of elastomer volume fraction and phase morphology on the elastic modulus of ternary composites polypropylene (PP)/ethylene-propylene rubber (EPR)/inorganic filler containing 30 vol % of either spherical or lamellar filler has been investigated. Phase morphology was controlled using maleated polypropylene (MPP) and/or maleated ethylene-propylene elastomer (MEPR). As revealed by SEM observations, composites of MPP/EPR/filler exhibit separation of the filler and elastomer and good adhesion between MPP and the filler, whereas composites of PP/MEPR/filler exhibit encapsulation of the filler by MEPR. Composite models were utilized to estimate upper and lower bounds for the elastic modulus of these materials, which is strongly dependent on the morphology of the ternary composite. A model based on the Kerner equation for perfect separation of the soft inclusions and rigid fillers gives a good prediction of the upper limit for relative elastic modulus as a function of filler and elastomer volume fractions. The lower limit, achieved in the case of perfect encapsulation, depends significantly on the particle shape. Good agreement was found between experimental data and lower limits predicted using the Halpin-Tsai equation for lamellar filler and the Kerner-Nielsen equation for spherical filler. In order to calculate reinforcing efficiency of the core-shell inclusions, the finite element method (ANSYS 4.4A, GT STRUDL) has been used.     

Effect of elastomer on polypropylene/nylon-12 blends

Various compositions of polypropylene (PP)/nylon-12 blends with elastomer were prepared. Morphologies and mechanical properties of the blends were studied. In particular, the effect of ethylene-propylene (EP) elastomer and maleic anhydride-grafted ethylene propylene elastomer (Ma-g-EP) on the PP/nylon-12 blends were investigated. The results showed that PP/nylon-12 blends have inferior mechanical properties because of their poor compatibility and dispersion. The EP elastomer has a limited effect on the blends since the mechanical properties of PP/nylon-12 blends were controlled by their interface. The Ma-g-EP elastomer improved the mechanical properties of PP/nylon-12 blends through improvement of the interface between PP and nylon-12, and compatibility between the elastomer and nylon-12. Differential scanning calorimetry (DSC) and scanning electron microscopy (SEM) were used to characterize microstructures. The dispersion of components and the compatibility between PP and nylon-12 were significantly improved with addition of the Ma-g-EP elastomer.     

Effect of morphology on the behaviour of ternary composites of polypropylene with inorganic fillers and elastomer inclusions

The effects of phase morphology, interfacial adhesion, rigid filler particle shape and elastomer volume fraction on the tensile yield strength of polypropylene (PP) filled with inorganic filler (CaCO₃ or Mg(OH)₂) and ethylene-propylene elastomer (EPR) were investigated. Separation of the filler and elastomer particles was achieved using maleic-anhydride-grafted PP (MPP) to enhance the filler-matrix adhesion. Encapsulation of the rigid filler by the elastomer was achieved using maleic-anhydride-grafted EPR (MEPR) to increase the filler-elastomer adhesion. The two limiting morphologies differ significantly in mechanical properties under tensile loading at the same material composition. Elastomer particles separately dispersed in the matrix enhance the shear banding in the bulk matrix which prevents the crazes growing from the filler surface from becoming unstable and, thus, increases the ductility of the material. Encapsulation by an elastomer layer on the filler surface relieves triaxial stresses at the filler surface, changing the major local failure mechanism from crazing to shear yielding and, hence, increasing the ductility of the material. Increase of the elastomer volume fraction also causes, in both cases, an increase in matrix ductility. Composite models are used to predict upper and lower limits of yield strength (_y) for the two limiting morphologies over an interval of elastomer volume fractions (V _e) from 0 to 0.2 at a constant filler loading of 30 vol.% and over a filler volume fraction from 0 to 0.4 at a constant EPR content in the matrix. Satisfactory agreement was found between the experimental data and theoretical predictions.     

采用β成核动态硫化PP/EPDM共混物增韧聚丙烯

采用β成核的动态硫化iPP/EPDM共混物即热塑性硫化胶(TPV)改性聚丙烯,并与通用增韧剂聚烯烃弹性体(POE)、三元乙丙橡胶(EPDM)增韧聚丙烯进行比较,考察了增韧体系的力学性能、热性能和相形态.结果表明,随增韧剂含量的增加,增韧体系的拉伸屈服强度和弯曲模量均有所下降,而冲击强度提高.TPV改性体系的强度、模量和...     

Crumpling and Unfolding of Montmorillonite Hybrid Nanocoatings as Stretchable Flame‐Retardant Skin

Flame‐retardant coatings are widely used in a variety of personnel or product protection, and many applications would benefit from film stretchability if suitable materials are available. It is challenging to develop flame‐retardant coatings that are stretchable, eco‐friendly, and capable of being integrated on mechanically dynamic devices. Here, a concept is reported that uses pretextured montmorillonite (MMT) hybrid nanocoatings that can undergo programed unfolding to mimic the stretchability of elastomeric materials. These textured MMT coatings can be transferred onto an elastomeric substrate to achieve an MMT/elastomer bilayer device with high stretchability (225% areal strain) and effective flame retardancy. The bilayer composite is utilized as flame‐retardant skin for a soft robotic gripper, and it is demonstrated that the actuated response can manipulate and rescue irregularly shaped objects from a fire scene. Furthermore, by depositing the conformal MMT nanocoatings on nitrile gloves, the firefree gloves can endure direct flame contact without ignition.     

Failure mechanics in ternary composites of polypropylene with inorganic fillers and elastomer inclusions

The effects of phase morphology, interfacial adhesion and filler particle shape and volume fraction on the fracture toughness of polypropylene (PP) filled with CaCO₃ or Mg(OH)₂ and ethylene-propylene elastomer (EPR) were investigated. Separation of the inorganic filler and elastomer particles was achieved using maleic-anhydride-grafted PP (MPP) to enhance the inorganic filler-matrix adhesion. Encapsulation of the rigid filler by the elastomer was achieved by using maleic-anhydride-grafted EPR (MEPR) to increase the inorganic filler-elastomer adhesion. The two limiting morphologies differed significantly in fracture toughness under impact loading at the same material composition. A model for a mixed mode of failure, accounting for the plane strain and plane stress contributions to the strain energy release rate,G _c, was used to predict the upper and lower limits forG _c for the two limiting morphologies over an interval of elastomer volume fractions,v _e, from 0–0.2 at a constant filler volume fraction,V _f = 0.3, and over the filler volume fraction from 0–0.4 at constant EPR content. The role of material yield strength in controlling fracture toughness has been described successfully using Irwin's analysis of plastic zone size. The presence of elastomer enhances both the critical strain energy release rate for crack initiation,G _c, and the resistance to crack propagation as expressed by Charpy notched impact strength for the two limiting morphologies. Satisfactory agreement was found between the experimental data and predictions of upper and lowerG _c limits.     

Polymers Move in Response to Light

Significant advances have recently been made in the development of functional polymers that are able to undergo light‐induced shape changes. The main challenge in the development of such polymer systems is the conversion of photoinduced effects at the molecular level to macroscopic movement of working pieces. This article highlights some selected polymer architectures and their tailored functionalization processes. Examples include the contraction and bending of azobenzene‐containing liquid‐crystal elastomers and volume changes in gels. We focus especially on light‐induced shape‐memory polymers. These materials can be deformed and temporarily fixed in a new shape. They only recover their original, permanent shape when irradiated with light of appropriate wavelengths. Using light as a trigger for the shape‐memory effect will extend the applications of shape‐memory polymers, especially in the field of medical devices where triggers other than heat are highly desirable.     

热塑性弹性体的研究与产业化进展

化学合成型和共混型热塑性弹性体类型、市场概况、产业化进展及最新研究发展方向进行了论述。介绍了几种具有市场应用前景的新型热塑性弹性体品种,如聚酰胺类TPE、热可逆共价交联类TPE、茂金属催化聚烯烃类TPE、甲壳型液晶类TPE、生物基TPE、新型热塑性硫化橡胶等,对它们的制备方法、性能特点及市场发展概况进行了详细论述,并对它们的应用领域和产业化方向进行了评述和展望。     

Water Based Silicone Elastomer Controlled Release Tablet Film Coating 1: Free Film Evaluation

A latex which is a polymerized and cross-linked product of hydroxyendblocked polydimethylsiloxane and an alkoxysilane has been evaluated as a controlled release tablet film coating system. With adequate reinforcement of colloidal silica, the silicone elastomer latex formed solid elastomeric free films upon drying. Polyethylene glycols of different molecular weights were incorporated in the coating system to enhance the permeability of the silicone elastomer to hydrophilic and ionic species. Free films derived from the three-component silicone elastomer dispersions were evaluated by various physical and chemical methods with respect to their suitability as an aqueous controlled release film coating system.     

Compatibility and morphology of blends of isotactic and atactic polypropylene

The compatibility and morphology of blends of isotactic and atactic polypropylene have been studied by several means: X-ray scattering, differential scanning calorimetry, and electron microscopy. It was found that the atactic polymer was located mainly inside the spherulites of the isotactic polypropylene on a scale approximately equal to that of the crystalline lamellae. This means that these two polymers were more intimately mixed than are blends of polypropylene and ethylene-propylene copolymer, in which the location of the copolymer is unrelated to the spherulite structure. This difference can be explained by the fact that atactic and isotactic polypropylene are miscible in the melt, whereas polypropylene and ethylene-propylene copolymer are not.