Impact of adhesive ingredients on adhesion between rubber and brass-plated steel wire in tire

Proficiency on underlying mechanism of rubber-metal adhesion has been increased significantly in the last few decades. Researchers have investigated the effect of various ingredients, such as hexamethoxymethyl melamine, resorcinol, cobalt stearate, and silica, on rubber-metal interface. The role of each ingredient on rubber-metal interfacial adhesion is still a subject of scrutiny. In this article, a typical belt skim compound of truck radial tire is selected and the effect of each adhesive ingredient on adhesion strength is explored. Out of these ingredients, the effect of cobalt stearate is found noteworthy. It has improved adhesion strength by 12% (without aging) and by 11% (humid-aged), respectively, over control compound. For detailed understanding of the effect of cobalt stearate on adhesion, scanning electron microscopy and energy dispersive spectroscopy are utilized to ascertain the rubber coverage and distribution of elements. X-ray photoelectron spectroscopy results helped us to understand the impact of Cu_XS layer depth on rubber-metal adhesion. The depth profile of the Cu_XS layer was found to be one of the dominant factors of rubber-metal adhesion retention. Thus, this study has made an attempt to find the impact of different adhesive ingredients on the formation of Cu_XS layer depth at rubber-metal interface and establish a correlation with adhesion strength simultaneously.     

偶联剂B对RTV硅橡胶粘接强度的影响

为了提高RTV硅橡胶与金属材料的粘接强度 ,对金属材料表面采用偶联剂处理 ,筛选了多种偶联剂 ,进行了稳定性和加速老化试验 ,测试了试件的剪切强度和扯离强度 ,结果表明偶联剂B具有较佳的性能 ,不仅能够提高粘接强度 ,而且粘接强度稳定     

Enhancing adhesive joints between commercial rubber (SBS) and polyurethane by low-pressure plasma surface modification

The paper presents research on the two-stage process of low-pressure plasma surface modification of a commercial SBS rubber, improving its adhesion to both the polyurethane adhesive in an organic solvent (PU) and the aqueous polyurethane adhesive dispersion (ADPU). The plasma surface modification process was carried out in a flow reactor with parallel plate electrodes, in which plasma was generated by an RF glow discharge (13.56 MHz). In the first stage of the process, the Ar or O₂ plasma was used, and then, as the second stage of the modification process, the treatment was performed in H₂O plasma. The adhesive properties of the plasma-modified SBS rubber surface were determined using the 180^o-peel strength test (PS). These results were correlated with surface properties investigated using contact angle (CA) measurements, FTIR-ATR spectroscopy, XPS spectroscopy and scanning electron microscopy (SEM). The observed improvement in wettability of the plasma modified surface was attributed to the formation of hydroxyl groups, which was confirmed by spectroscopic methods (FTiR-ATR and XPS). The results of the 180^o-peel strength test showed, in turn, a clear relationship between the capacity of adhesive bonding and the amount of oxygen groups (mainly the hydroxyl groups) as well as the surface roughness, determined by SEM microscopy. It was also found that the effects of the plasma surface modification of the SBS rubber were stable for at least 72 h. The results of this work prove that cleaning and etching of the commercial SBS rubber surface in the first stage of its plasma treatment, followed by chemical modification in the second stage, lead to very strong adhesive joints.     

Hydrophobic recovery of repeatedly plasma-treated silicone rubber. Part 1. Storage in air

Silicone rubber is used for a wide variety of biomedical and industrial applications due to its good mechanical properties, combined with a hydrophobic surface. Frequently, however, it is desirable to alter the surface hydrophobicity of silicone rubber. Often this is done by plasma treatments but the effects are usually transient. In this study, surfaces of medical grade silicone rubber have been repeatedly modified by means of oxygen, argon, carbon dioxide, and ammonia RF plasma treatments with a 24 h time interval in between treatments. Treated samples were stored in air prior to surface characterization by water contact angle measurements, X-ray photoelectron spectroscopy (XPS), streaming potential measurements, and profilometry for surface roughness. The carbon percentage of the surfaces decreased after plasma treatment, while the silicon and oxygen percentages increased irrespective of the plasma used. The formation of Si-O-Si bridges between siloxane chains after plasma treatment was demonstrated by the appearance of a new component in the Si_2p peak but the degree to which this occurred differed per gas. Streaming potential measurements in a 10 mM potassium phosphate buffer indicated a more negatively charged surface for treated samples compared to untreated samples (-23.3 mV at pH 7.0). Surface roughness increased slightly for repeatedly plasma-treated samples from R_A = 0.35 μm to R_A = 0.46 μm, while scanning electron microscopy showed the presence of several 'cracks' spanning the surface after repeated treatment. Argon, carbon dioxide, and ammonia plasmas significantly reduced the advancing water contact angle from 115° to 58°, 72°, and 85°, respectively, on a more permanent basis (especially when the treatments were repeated after recovery). Oxygen plasma effects on water contact angles generally disappeared within 5 h, also after repeated treatment.     

增强橡胶与金属材料粘接的表面处理技术

表面处理是提高橡胶与金属材料粘接性能的重要工艺之一。介绍了目前橡胶和金属几种常用的表面处理技术,如橡胶表面采用的卤化法、硫酸法、等离子体法、紫外线法和臭氧法以及电晕处理法等,金属表面采用的机械法、化学法、阳极氧化法、镀黄铜法、硅烷偶联剂处理法等,提出了橡胶金属粘接表面处理技术的发展方向。     

镀层对钢丝帘线与橡胶粘合性能的影响

研究高铜镀层(铜质量分数为0.670)和低铜镀层(铜质量分数为0.635)钢丝帘线与橡胶的粘合性能.结果表明,高铜镀层钢丝帘线与橡胶的初始粘合性能较好,但其老化后粘合性能下降明显;只要胶料配方合理,低铜镀层钢丝帘线与橡胶的初始粘合性能可接近高铜镀层钢丝帘线,而其老化后粘合性能明显优于高铜镀层钢丝帘线.     

Hydrophobic recovery of repeatedly plasma-treated silicone rubber. Part 2. A comparison of the hydrophobic recovery in air,water, or liquid nitrogen

Surfaces of medical grade silicone rubber (Q7-4750, Dow Corning) were modified by repeated (six times) RF plasma treatments using various discharge gases: oxygen, argon, carbon dioxide, and ammonia. The treated samples were stored for a period of 3 months in ambient air, water, or liquid nitrogen. Subsequently, the temporal behavior of the effects of the plasma treatment on the physicochemical surface properties of the silicone rubber was investigated using water contact angle measurements and X-ray photoelectron spectroscopy (XPS). Hydrophobic recovery during 3 months storage in ambient air was considerable and nearly complete for all four plasmas used. Hydrophobic recovery was almost completely suppressed during storage in liquid nitrogen, and only a minor increase of around 10° in advancing water contact angle was observed for all four plasma treatments. Also during storage of treated samples in water, hydrophobic recovery was minimal and initiated again by returning the treated samples to ambient air. XPS analyses showed that argon, carbon dioxide, and ammonia plasma-treated silicone rubber all had increased carbon percentages at the expense of oxygen and silicon after storage in water, or in liquid nitrogen, compared with after storage in ambient air. Interestingly, the carbon content of oxygen plasma-treated silicone rubber decreased during storage in water, or in liquid nitrogen, compared with storage in ambient air, while its oxygen and silicon percentages increased.     

Effect of the thermal history of a rubber composite on the adhesion strength

In this study, the geometry of the tyre cord adhesion test (TCAT) was used to evaluate the adhesion strength between rubber and fibre. The activation energy (ΔE) of rubber compound used in this study was 72.43 kJ mol^?1 and the difference of cure state between the inside and outside regions of the TCAT specimen with curing time was elucidated using the value of ΔE. The difference in cure state between the inside and outside regions of the TCAT specimen corresponded to the effect of 5.06 min of curing time. The cure state of the inside region of the TCAT specimen greatly affected the final adhesion strength and the results were confirmed by additional experiments. It was concluded that optimum adhesion between rubber and cord could not be obtained in a TCAT specimen unless the additional curing time to reach the optimum cure state of the inside region of the TCAT specimen was taken into account. Copyright © 2004 Society of Chemical Industry     

仿生材料多巴胺对橡胶/钢丝帘线黏合性能的影响

选用子午线轮胎胎体胶料配方作为基本配方,以钢丝帘线作为骨架材料,采用自行研发的橡胶与钢丝帘线动态黏合性能的测试方法,考察了多巴胺及传统黏合体系对橡胶/钢丝帘线动态黏合性能的影响,并探讨了多巴胺替代间苯二酚作为无毒环境友好型黏合剂的可行性。结果发现,钴盐黏合体系赋予了橡胶与钢丝帘线较好的动态黏合,多巴胺体系赋予了较好的静态黏合,间甲白体系居中,3种黏合体系并用可赋予最好的动、静态黏合性能。橡胶/钢丝帘线的动、静态黏合力均随着多巴胺用量的增加而增大,但在拉伸疲劳后出现下降。     

超细碳酸钙表面处理及其在RTV硅橡胶中的应用(一)

采用自制的超细碳酸钙悬浊液,在碳酸钙表面包覆二氧化硅,改善碳酸钙的应用性。采用吸油值、耐酸性、沉降体积等测试方法衡量二氧化硅的包覆效果。实验结果表明能够在碳酸钙表面形成较为紧密的二氧化硅膜。     

Modification of a nitrile-phenolic bonding agent by addition of an interfacial agent: effect on the practical adhesion between nitrile rubber and metal

—The mechanism of vulcanization bonding of a nitrile rubber (NBR) elastomer to metal with a single-coat nitrile-phenolic bonding agent is discussed. A nitrile-phenolic bonding agent consisting of NBR, phenol formaldehyde (PF) resin, and vulcanizing agents was modified with an interfacial agent (p-cresol formaldehyde resin) and the effect of interfacial agent addition on the practical adhesion between metal and the NBR elastomer after vulcanization was investigated. The adhesion strength was measured in terms of the metal-to-NBR elastomer peel strength using the bonding agent. The addition of p-cresol formaldehyde (PCF) resin to the bonding agent with a proportionate reduction of PF resin initially improved the peel strength; a maximum was reached at about 20% PCF content and then decreased with a further increase in the PCF content. The improvement in peel strength produced by the addition of PCF resin is attributed to the increased chemical bonding between NBR and the phenolic resin. The drop in peel strength above 20% PCF content is explained by the increased diffusion of the bonding agent into the NBR elastomer, away from the bond line, leading to a starved glue line. The mechanism for the optimum performance at about 20% PCF resin content is believed to be due to the balance of diffusion and chemical crosslinking.     

炭黑和白炭黑与偶联剂Si 69的相互作用

采用抽提分析、X射线光电子能谱和透射电子显微镜研究了偶联剂(Si69)改性炭黑和白炭黑。结果表明，发黑和白炭黑均与Si69产生了化学作用，并且白炭黑与Si69的作用要比炭黑与Si69的作用更明显。     

Derivatization of discharge-treated LDPE: an extension of XPS analysis and a probe of specific interactions in adhesion

Specific reactions for the derivatization of oxygen-containing functional groups in polymer surfaces have been developed in order to improve the precision of analysis by X-ray photoelectron spectroscopy (xps). These have been used to probe the chemical composition of low density polyethylene (ldpe) surface-modified by electrical discharge treatment. Simultaneously the effect of derivatizing particular groups on the auto-adhesive behaviour of these surfaces has been examined. Two independent specific interaction mechanisms have been identified.     

Effect of silane treatment on adhesion of adhesive-bonded carbon fiber reinforced nylon 6 composite

In this study, a silane coating, KH560, along with an abrasion pretreatment procedure for carbon fiber reinforced PA 6 composite with 30% mass fiber (C_f/PA6) and AA6061-T4 was developed. Composition and structure of this silane coating and effect of this coating on the strength and water resistance of the adhesive-bonded C_f/PA6 and AA6061 were investigated. Test results revealed that silane pretreatment improved the static strengths of the adhesive-bonded C_f/PA6-C_f/PA6 and C_f/PA6-AA6061 by 23% and 21%, respectively. X-ray photoelectron spectroscopy (XPS) analysis of the adhesive-bonded treated C_f/PA6 indicated that the improvement in strength was primarily attributed to the formation of Si-O-Si and Si-N covalent bonds on the surface of C_f/PA6, which enhanced the bond adhesion between the silane coating, adhesive, and adherends. In addition, abrasion of adherends prior to silane pretreatment further improved the strengths of the adhesive-bonded C_f/PA6-C_f/PA6 by another 20%. While silane and abrasion-silane treatment improved the strength of the adhesive-bonded C_f/PA6-C_f/PA6 and C_f/PA6-AA6061 in ambient conditions, the strength of water immersed silane coated joints with and without abrasion was decreased by about 50% (i.e., immersed in water at 54 °C for one week). All tested bare and treated joints with and without water immersion exposure were fractured in adhesive mode. Analyses of the test results revealed that to improve the failure mode and bond strength it is necessary to form a Si-N functional group in the silane coating by thoroughly cleaning and removing the contaminants and weak layers on the surface of C_f/PA6.     

Dry adhesion study of polyester/melamine clear coats on galvanized steel

The dry adhesion strength of polyester/melamine clear coats varying in their branching degrees were applied on galvanized steel panels and investigated by pull-off and T-bend testing. It was found that pull-off tensile adhesion is mainly dominated by the type of coating and less influenced by the pretreatment of the substrate. In contrast, the critical T-bend strain is mainly affected by the surface treatment of the galvanized layer with higher stiffness but lower ductility compared to the clear coat. Pull-off tensile strength at room temperature is correlating with the glass transition temperature T_g and a strong viscoelastic contribution is ascribed to the work of adhesion. Samples with adhesive as well as cohesive failure modes were further investigated by X-ray photoelectron spectroscopy (XPS) to determine the interfacial chemistry. Angle-resolved XPS data suggest that the nitrogen from the melamine crosslinker plays a decisive role for the adhesion of the coatings. Regarding the melamine distribution a micro- and a nanostructural effect has to be considered: while maximum melamine concentrations over coating depth are usually found in the bulk region of these clear coats, this work proposes that the remaining melamine at the interface segregates towards the metallic substrate.     

低温等离子法提高芳纶布与硅橡胶粘接性能的研究

采用低温等离子法处理芳纶布,并在硅烷偶联剂的作用下,考查低温等离子处理对芳纶布与硅橡胶粘接性能的影响。研究结果表明,经低温等离子处理过的芳纶布,其表面粗糙度和羟基含量明显提高,同时在乙烯基三乙氧基硅烷(A151)作用下,芳纶布与硅橡胶间的粘接性能明显改善,且随着处理时间的延长,改善幅度增加。     

硅烷偶联剂对纳米二氧化硅/硅橡胶复合材料界面作用及性能的影响

利用单官能团偶联剂六甲基二硅氮烷(HMDS)及双官能团偶联剂γ-甲基丙烯酰氧基丙基三甲氧基硅烷(KH-570)分别对纳米Si O2进行表面改性,制备了改性Si O2/甲基乙烯基硅橡胶(MVQ)复合材料,研究了2种偶联剂对Si O2的改性效果,表征了改性Si O2在MVQ中的分散状态,且考察了2种偶联剂对复合材料结合胶、动态力学性能、交联密度及拉伸性能的影响。结果表明,HMDS和KH-570都能实现对Si O2改性接枝,且2种改性Si O2具有相同的摩尔接枝率;HMDS改性Si O2分散于基体中,且存在一定量团聚体,而KH-570改性Si O2的分散性较好,部分达到原生粒子级分散,颗粒与基体相容性提高;低应变条件下,Si O2经改性后,复合材料的储能模量(G')和损耗因子(tanδ)下降,且KH-570改性体系的G'低于HMDS改性体系,而tanδ高于HMDS改性体系;在高应变条件下,未改性与改性Si O2/MVQ复合材料的G'趋于一致,而KH-570改性体系的tanδ低于HMDS改性体系;改性Si O2/MVQ复合材料具有更高的交联密度和拉伸性能,且KH-570改性体系的交联密度和拉伸性能均高于HMDS改性体系。     

Effect of bis(3‐triethoxysilylpropyl) tetrasulfide on the crosslink structure,interfacial adhesion,and mechanical properties of natural rubber/cotton fiber composites

Bis(3‐triethoxysilylpropyl) tetrasulfide (TESPT) was used to improve the interfacial adhesion between cotton fiber and natural rubber (NR). The crosslink density, interfacial adhesion, mechanical properties, dynamic mechanical properties, and morphology of NR/cotton fiber composites were investigated. The composites with TESPT had higher crosslink density, better mechanical properties, higher initial modulus, and higher yield strength than the composites without TESPT because of the difference in interfacial adhesion. The results of an interfacial adhesion evaluation, the high storage modulus and low damping values of the composites with TESPT, and the coarse surfaces of the pullout fibers implied the enhancement of interfacial adhesion. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Effect of non‐oiled sulfur concentration on the adhesion between nitrile rubber and nylon cord

The effect of non‐oiled sulfur concentration on the adhesion between nitrile rubber (NBR) and dipped or undipped Nylon 6,6 cords is discussed. The results show that using undipped cords with NBR (grade 34/50) enhance adhesion. In this article, the crosslink density of different nitrile rubber mixes were estimated to illustrate their effect on adhesion. The resistance to heat aging and ionizing radiation were also studied. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 74: 762–771, 1999     

偶联剂类型对溶聚丁苯橡胶/白炭黑复合材料性能的影响

从力学性能、动态压缩疲劳生热、动态力学性能等方面对比了分别由SnCl_4和SiCl_4偶联的溶聚丁苯橡胶(SSBR)与白炭黑所制备复合材料的性能,并利用测定结合橡胶含量、橡胶加工分析仪及Kraus模型等手段探讨了两种SSBR与白炭黑的相互作用。结果表明,与用SnCl_4偶联所制备的SSBR相比,经SiCl_4偶联制得的SSBR与白炭黑的相互作用力更强,白炭黑的分散性更好。所制备SSBR/白炭黑复合材料的力学性能更好,压缩温升更低,滚动阻力更小,抗湿滑性能更好。