Rubber Composite Materials Research Articles

B-21 シューズソールリサイクル材複合ゴムの開発(弾性体の開発と分析評価)

B-21 シューズソールリサイクル材複合ゴムの開発(弾性体の開発と分析評価)

Study on Short Basalt Fiber Reinforced Fluorine Rubber Composites

Fluorine rubber has excellent performance, such as cold resistance, heat resistance, ozone resistance thermal properties and so on. However, fluorine rubber is poor in the mechanical properties. In order to improve its availability of fluorine rubber, short basalt fiber/ fluorine rubber composite materials were prepared by using short basalt fiber as reinforcement, and its mechanical properties and compatibility were studied. The influence of the surface treatment on short basalt fibers, short basalt fiber content on the mechanical properties of short basalt fiber reinforced fluorine rubber composites were studied. The best formulation of short basalt fiber/ fluorine rubber composite materials were determined by testing Shore A hardness, tensile strength and elongation at break. The results show that the formula obtained best mechanical properties is 100 phr fluorine rubber, 10 phr short basalt fiber, and 2.5 phr KH-550. And further demonstrate that compatibility of short basalt fiber / fluorine rubber with KH550 is best by SEM and IR analysis. And prepare excellent performance of fluorine rubber composite materials.

Performance Evaluation of Spring for the Vehicle Suspension System Using the Nonlinear Finite Element Method

Air spring is used for the suspension system and it affects the vehicle stability and riding comfort by improving the impact-relief, braking, and cornering performance. Air Spring is comprised of the upper plate, lower plate, and rubber sleeve. Rubber sleeve is the composite material, which is made up of combination of rubber and Nylon, and the characteristics are changed according to the shape of rubber-sleeve, the angle of reinforcement cord. In this study, the distribution of internal stresses and the deformation of rubber composite material are analyzed through the nonlinear finite element method. The result showed that the internal maximum stresses and deformations about the changes of cord angle caused the more the Young's modulus decrease, the more maximum stress reduced.

Effect of Electrical Conductivity and Physical Performance about Vulcanization System in Conductive Silicon Rubber

Vulcanization methods of conductive silicon rubber are described in this paper. Several common vulcanization agents are also be introduced. The conductivity and mechanical properties of the conductive silicon rubber composite materials are effected by vulcanization systems. The influence degree is introduced by respectively using different vulcanization method, vulcanizing time and vulcanizing temperature. The research progress of vulcanization system of conductive polymer composites is elaborated.

Quantitative Electron Tomography of Rubber Composites

Rubber composite materials have many applications, one example being tyre manufacture. The presence of a filler material in the composite (such as carbon black or silica) causes its mechanical properties to differ in several ways when compared to pure rubber such as viscoelastic behaviour (the Payne effect), increased tensile strength and improved wear resistance. To fully understand these properties, it is necessary to characterise how the filler material is organised on the nanoscale. Using composite materials representative of those found in tyres, this work illustrates the use of electron tomography and machine learning methods as tools to describe the percolation behaviour of the filler; in this case, we focus on the largest proportion of particles absorbed into one single object as a function of particle spacing.

Enhancing the Piezoresistance Senstivity and Repeatability of Carbon Nanotube/Silicone Nanocomposites

The nanocomposites of carbon nanotube/polymer have been studied to explore their piezoresistance properties, which can be used as smart materials in the fields like biomedical engineering, robotic engineering, and advanced instrumentation. The differences in piezoresistance behavior of the previous studies were explained by the less uniformity of carbon nanotubes. To clarify the resistance versus deformation relations for carbon nanotube/silicone rubber composite materials, we have fabricated composite materials with various nanotube and carbon black contents. The measurements show that the resistance versus deformation sensitive range is depends on both the content of nanotube and carbon black, while the tiny variation of content of the carbon black affects largely the total piezoresistance sensitivity and repeatability. The experiment shows that adequate amount of carbon balck mixed with carbon nanotube can improve the piezoresistance repeatability. The deformation induced variation of the conducting percolation network shall be the dominating mechanism for the piezoresistance behavior of carbon nanotube/silicone rubber composites.

Influence of tire-cord layers and arrangement direction on the physical properties of polyester tire cord reinforced with chloroprene rubber composite materials

AbstractPolyester tire cord is used as reinforcement for making chloroprene rubber (CR) composite materials. This study investigated the influences of polyester tire-cord layers and arrangement direction on the mechanical properties of CR composite materials. The experimental results indicate that the optimal temperature and heating time for CR vulcanization are 170°C and 35 min, respectively. This processing condition enabled CR to achieve rapid vulcanization and exhibit optimal mechanical properties. The hardness and compression stiffness of the CR composites increased with increasing tire-cord layers. This phenomenon reduced the occurrence of creep under long-term loading but increased the compression set. In addition, when the arrangement direction of the tire cord and the stretching direction of CR were perpendicular, crack formation and growth easily developed, which reduced the bending-fatigue resistance of CR.

Novel HDPE/ground tyre rubber composite materials obtained through in‐situ polymerization and polymerization filling technique

ABSTRACTNovel hybrid materials composed by a high density polyethylene (HDPE) matrix and powdered rubber coming from scrap tyres (ground tyre rubber [GTR]) were prepared. Two methods were followed: ethylene was polymerized by a metallocene catalyst (Cp2ZrCl2/methylaluminoxane) in the presence of a toluene dispersion of the filler (in‐situ polymerization); and the ethylene was polymerized out after supporting the aluminum‐based co‐catalyst onto the rubber particles surface (polymerization filling technique). The experimental conditions were varied in order to achieve the best catalyst productivity. All the synthesized composites were characterized in order to investigate the occurrence and the extent of interactions between HDPE macromolecular chains and the GTR components and their effects onto the final properties, by comparison with a composite where GTR was included into the matrix through blending in the melt. Scanning electron microscopy, atomic force microscopy, and solvent extractions were performed to this aim. The amount of thermoplastic matrix bonded to the filler was determined, and the extracted polymer was characterized by size exclusion chromatography and differential scanning calorimetry. Finally, stress–strain behavior of the composites obtained, respectively, by catalytic polymerization and melt mixing was compared. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40313.

Study of Applying Aramid Fiber Treated Insurface to EPDM Rubber Composite Materials

The surface of aramid fiber is very smooth and chemical inert.The adhesiveness of aramid fiber with EPDM rubber materials is not good.So the tensile strength of EPDM rubber composite materials is influenced seriously.This paper modified the surface of aramid fiber with silicon coupling agentKH-550. We test the chang of fibers in surface with the ESCA,and the result is that content of carbon decreased ,while content of nitrogen and oxygen element increased.The activity of surface of fiber has been increased. Strength of composite materials increased from 2.58MPa to 3.22 MPa . The SEM photos of samples indicate that the weight of EPDM rubber on surface of EPDM rubber is more than untreated fiber composite materials .The treating effect on aramid fiber is best when the concentration of KH-550 is 5%,5hours.

Detection of internal cracks in rubber composite structures using an impact acoustic modality

The objective of this study is to investigate the use of impact acoustic signals to non-intrusively inspect rubber composite structures for the presence of internal cracks, such as those found in an automobile tyre. Theoretical contact dynamic models for both integral and defective rubber structures are developed based on Hertz's impact model, further modified for rubber composite materials. The model generates the prediction of major impact dynamic quantities, namely the maximum impact force, impact duration and contact deformation; such parameters are also theoretically proven to be correlated with the presence of internal cracks. The tyre structures are simplified into cubic rubber blocks, to mitigate complexity for analytical modelling. Both impact force and impact sound signals are measured experimentally, and extraction of useful features from both signals for defect identification is achieved. The impact force produces two direct measurements of theoretical impact dynamic quantities. A good correlation between these experimental discriminators and the theoretical dynamic quantities provide validation for the contact dynamics models. Defect discriminators extracted from the impact sound are dependent on both time- and frequency-domain analyses. All the discriminators are closely connected with the theoretical dynamic quantities and experimentally verified as good indicators of internal cracks in rubber composite structures.

Study on Short Basalt Fiber Reinforced Silicone Rubber Composites

Silicone rubber has excellent performance, such as cold resistance, heat resistance, ozone resistance, thermal properties and insulating properties and so on. However, silicone rubber is in the state of semi-liquids and it is very soft, so the mechanical properties of silicone rubber are very poor. In order to improve its availability of silicone rubber, short basalt fiber / silicone rubber composite materials were prepared by using short basalt fiber as reinforcement, and its mechanical properties and compatibility were studied. The best formulation of short basalt fiber / silicone rubber composite materials were determined by testing Shore A hardness, tensile strength and elongation at break, and the morphology structure and compatibility of short basalt fiber / silicone rubber composite materials were discussed by scanning electron microscope and infrared spectrum, prepare excellent performance of silicone rubber composite materials.

Genetic Algorithm–Based Design and Development of Particle-Reinforced Silicone Rubber for Soft Tooling Process

In order to enhance the solidification rate of soft tooling process, design of a silicone rubber composite mold material is carried out based on multiobjective optimization (MOO) of conflicting objectives. The elitist nondominated sorting genetic algorithm (NSGA-II), a genetic algorithm–based MOO tool, is used to find the optimum parameters first by obtaining the Pareto-optimal front and then selecting a single solution or a small set of solutions for manufacturing applications using a suitable multi-criterion decision making technique. Based on the optimal design parameters, an experimental study in soft tooling process is carried out in particle-reinforced silicone, and it is observed that the solidification time is minimized appreciably keeping the same advantages of soft tooling process.

Development of a detailed aircraft tyre finite element model for safety assessment

This paper describes the development of a detailed finite element (FE) model of an aircraft test tyre in order to investigate its performance and assess its safety criteria. It is noticed that rubber and fabric composite materials are the major components of this tyre model and their characterization requires tests and correlation. The characterization of such materials is of great importance in the model development process.Due to its complicated mechanical behaviour that exceeds the linear elastic theory, rubber is generally considered as hyperelastic material in FE analysis. It can be defined by a stored energy function with various coefficients that need to be determined by a series of experimental test data. The key issue is to define an appropriate energy function that can provide good fit with the experimental test data.Initially, a full-scaled LS-Dyna FE model has been development to replicate the actual geometry of the target test tyre. The material properties of each individual component have been characterized and correlated with industrial uniaxial tension test data. The inflation and static load simulations have been analyzed basing on the characterized tyre model, indicating its reliability.The dynamic simulations that aim to duplicate tyre load upon aircraft landing scenarios have also been analyzed. Following the comments and guidelines from aircraft industrial data, the dynamic simulations have covered the tyre loading scenarios from normal (soft) landing, hard landing to crash landing under different aircraft landing weights and vertical speeds. The tyre deflection rate and the contact load have been chosen as the safety criteria. The simulation analysis, results and comments have been discussed in detail.The modelling and correlation processes described in this paper aim to demonstrate the importance of hyperelastic material characterization in developing a detailed FE tyre model. Such a predictive model can be effectively used during tyre design process to allow manufacturers to assess its availability, and also add to the general drive towards the use of more virtual prototypes in an area traditionally reliant on experimental testing.

Preparation and Performance of cis‐Polybutadiene Rubber Composite Materials Reinforced by Organic Modified Palygorskite Nanomaterials

The hydrophilic character of palygorskite has been modified by grafting organic group and controlling surface energy for improving compatibility of palygorskite in rubber matrix using palygorskite as cis‐polybutadiene rubber fillers. The effects of coupling modification on the performance of cis‐polybutadiene rubber materials filled with palygorskite were investigated, and the influence of coupling agent dosage on their mechanical properties was also studied. The results indicated that the mechanical performance of cis‐polybutadiene rubber materials reinforced by modified palygorskite could be improved significantly, and the tensile strength and tearing strength increased by 122.5% and 107.6% at the optimal dosage (15%) of coupling agent 3‐mercaptopropyl trimethoxysilane. Moreover, the reinforcement mechanism of rubber composite materials as prepared was also analyzed.

Improvement of Bending Fatigue Strength for Hybrid Cords with Carbon and Glass Fibers

Synchronous belts are rubber-composite materials with rubber, helical cords and facing fabrics. The helical cord is the tension member of the belt and is made of glass fibers, aramid fibers, or steel wires. Recent trends require increasingly high stiffness for the rubber belts. The use of carbon fibers and hybrid cords with carbon fibers are considered to be an effective way to achieve high stiffness for helical cords. This paper presents the study is to improve the bending fatigue strength of hybrid cords, where the center strand is made of carbon fibers, and the outer strands are made of glass fibers. The optimum cord composition for good bending fatigue durability is discussed following experimentation, mechanical analysis using a simplified mechanical model and FEM analysis. The model reasonably explained the initiation of the fatigue failure initiation site in the hybrid cords. The optimum cord composition was proposed for the bending fatigue strength basing on the simplified mechanical model. This was verified by experimental data showing good fatigue life. The use of such helical cords can considerably extend the operating life of synchronous belts.Copyright © 2009 by ASME

Research on Vulcanization Process of Short Fiber-Rubber Composite Material

Vulcanization process is the last step of manufacturing rubber products. For tire tread which is made of short fiber rubber composite material, vulcanization is complex due to during vulcanization process the flow of mixed rubber maybe change short fibers orientation. As a result, during vulcanization process, several pieces of iron wire have been put in the mold to play the role of tire patterns for the first step research. The experimental results indicate that the flow of mixed rubber would not change short fibers orientation greatly, and physical and mechanical properties of short fiber-rubber composite material keep as good as that vulcanized without iron wire.

Effects of Oil Palm Empty Fruit Bunch Filler on the Electrical Tree Propagation in Silicone Rubber

This paper presents the study on the effects of oil palm empty fruit bunch (OPEFB) micro-filler on electrical tree propagation in silicone rubber composite material. In this study, the oil palm empty fruit bunch (OPEFB) filler with mean size of 32μm was employed as an electrical tree inhibitor. The sample for this electrical tree experiment was in the form of leaf-like specimen which was characterized as filled sample and non-filled sample. The filled sample contained 1 wt% of OPEFB filler while the non-filled specimen contained no fillers. Obtained results show that the lengths of electrical trees in filled silicone rubber were shorter than tree length of non-filled silicone rubber for 60minutes propagation time. This tree length difference shows that the OPEFB micro-filler helped to retard the growth of electrical tree. Therefore, this new organic filler is found to be useful for electrical tree inhibitor in high voltage insulation.

Experimental investigation on equivalent properties of particle reinforced silicone rubber: Improvement of soft tooling process

The main disadvantage in soft tooling process using conventional flexible reactive polymeric mould materials, namely silicone rubber, is the longer solidification time of (wax/plastic) patterns that yields to reduce the rapidity of the process to a great extent, which is not desirable in the present competitive market. The approach of particle reinforcement with mould materials is introduced here to reduce the cooling time of soft tooling process and the resulting cooling time is experimentally investigated in considering a case of manufacturing of a typical wax pattern with aluminium particle–reinforced silicone rubber mould material. It is observed that cooling time is significantly condensed, particularly with higher loading condition of aluminium filler. This is due to the increase of equivalent thermal conductivity of mould material. However, it is also noticed that at the same time, the stiffness of mould becomes high due to the increase of equivalent modulus of elasticity of mould material. Therefore, in order to effectively utilize the particle-reinforced silicone rubber for preparing mould, it is important to have a perceptive on the equivalent thermal conductivity and modulus of elasticity of composite mould materials with different filler loadings. Based on this realization, an extensive study is carried out to find the effect on equivalent thermal properties and modulus of elasticity of silicone rubber composite mould materials with the reinforcement of various metallic and non-metallic filler particles independently through rigorous experimentation and correlation of experimental findings with the models cited in literatures.

Electrical Properties of Novel Lead Zirconate/Synthetic Rubber Composite Materials

Problem statement: Perovskite lead zirconate exhibits in an orthorhombic formation at a temperature below the Curie temperature, TC. Approach: The orthorhombic is non-centrosymmetric which is capable of spontaneous polarization (electronic, ionic and orientation), depending on their composition and volume fraction. Results: The results from FTIR spectroscopy, XRD patterns, and SEM indicate that the lead zirconate particles are dispersed in Acrylic Rubber (AR72) matrix. At a small amount of lead zirconate particulates present in the AR72 matrix, at nearly 0.3986% V/V (AR72/PZ_5), the electrical conductivity increases dramatically by two orders of magnitude. Conclusion/Recommendations: Our synthetic Rubber (AR72)/lead Zirconate (PbZrO3) composite materials can be successfully used as the candidate materials of soft Electroactive (ER) actuators, sensors, artificial muscles, and smart engineering devices.

The Performance of Barium Sulfate/Nature Rubber Composites Using in Sport Shoes

Modified barium sulfate (MBS) /nature rubber(NR) composite materials were prepared by direct blending methods. Barium sulfate was modified by coupling agent Si-69, titanium esters and stearic acid. Tensile property, hardness and wear resistance of composite materials were studied by various methods. The results showed that the modified barium sulfate fillers had great effect on the reinforcement of the composites.