Acrylic Rubber Research Articles

Thermal ageing, degradation and swelling of acrylate rubber, fluororubber and their blends containing polyfunctional acrylates

The thermal ageing and degradation behaviour of acrylate rubber (ACM) fluoroelastomer (FKM), and blends of ACM and FKM containing polyfunctional acrylates were studied in air and nitrogen atmospheres. The blends were also subjected to swelling in different solvents. Thermogravimetric analysis of the blends containing polyfunctional acrylate indicated higher thermal stability of the blends by shifting initiation of degradation to higher temperature. The ageing and degradation of FKM-containing blends resulted in elimination of hydrogen fluoride and formation of some lower molecular weight components. Polyacrylates with higher functionality showed multi-step degradation. Higher levels of polyacrylate in the blend resulted in an additional step of degradation compared to polyacrylate. Swelling studies indicated higher swelling resistance of ACM and FKM containing polyacrylate in solvents having different solubility parameters. Maximum swelling of the blends was observed with the solvents having solubility parameter values comparable to that of blends i.e. in the range of 9–10 MPa 1/2. The swelling index of the blends decreased with increasing level of polyfunctional acrylates. Higher functionality of polyfunctional acrylates decreased the swelling index.

Investigation of the effect of mixing schemes on cross-link distribution and tensile properties of natural–acrylic rubber blends

This article reports a study on the effect of mixing schemes on cross-link distribution and tensile properties of natural–acrylic rubber blends. Sulfur, MBT, ZnO, and stearic acid were used to compound the natural rubber (NR), whereas sodium stearate (soap) and sulfur were used to compound the acrylic rubber (ACM). The overall content of sulfur in the blend was 2.5 phr and the weight ratios of sulfur/MBT and sulfur/soap were kept constant at 1/2 and 1/5, respectively. Three types of mixing schemes were conducted. In scheme 1, the compounding ingredients were added simultaneously to a mixture of the rubbers. In scheme 2, ingredients were added separately to each of the relevant rubbers in separate compounding operations and sulfur was added to the mixture of rubbers at the end. In scheme 3, sulfur was premixed with ACM compound prior to blending with the NR compound. From the tensile test, it was found that the changes in mixing scheme significantly affect tensile properties of the rubber blends. The tensile strengths of the blends prepared by mixing schemes 2 and 3 were higher (5 MPa) than that of the blend prepared by mixing scheme 1. In addition, the tensile elongation increased by ~300% and the modulus increased by ~500 kPa due to the same effect. By performing a differential swelling for various blends, it was found that volume fraction ( V r) of the ACM phase in the swollen gel increased when the mixing scheme was changed from scheme 1 to scheme 2 and 3. On the other hand, V r of NR phase in the swollen gel barely changed with the mixing method. Finally, swollen state 1H-NMR of various blends was carried out and the results were compared to those obtained from the differential swelling technique.

A study on morphology and physical properties of natural–acrylic rubber blends

AbstractMorphology and physical properties of natural–acrylic rubber blends were investigated as a function of blend compositions and mixing methods. In the first method, the masticated natural rubber was cross‐blended with the acrylic rubber for 15 min, followed by a sequential addition of vulcanizing chemicals (ZnO, stearic acid, MBT, sodium stearate, and sulfur), and the mixing was terminated within 15 min. In the second method, the masticated natural rubber was premixed with its relevant vulcanizing chemicals (excepting the sulfur) for 7 min, followed by blending it with the acrylic rubber and sodium stearate for 20 min. Finally, the sulfur was added and the mixing was continued for further 3 min before termination. The resulting blends were vulcanized to their optimum cure time in a compression mold. The rubber sheet was cut into a dumbbell‐shaped specimen, and tensile properties were determined at a cross‐head speed of 500 mm/min. The morphology of the blends was examined with scanning electron microscopy (SEM). The SEM specimen was prepared by cryo‐fracturing, followed by staining with OsO4. It was found that all of the rubber blends were immiscible, as shown by there being two separated phases in the SEM micrographs. The result was in a good agreement with that from a thermal analysis (using a differential scanning calorimeter), which showed two glass transition temperatures. Morphology of the rubber blends changed from a cocontinuous morphology to a dispersed particle morphology as the natural rubber content was increased from 20% to 80% by weight. Increasing the natural rubber content enhanced tensile properties of the rubber blends at the expense of their oil and heat resistance. Most of these properties being examined seemed to be unaffected by the mixing method, with the exception of the retention of tensile strain after aging. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 1532–1539, 2002

Modification of waterborne polyurethane by forming latex interpenetrating polymer networks with acrylate rubber

Polyurethane (PU)/poly(acrylic rubber) (PAR) latex interpenetrating polymer networks based on waterborne PUs were prepared by sequential polymerization with methyl acrylate, ethyl acrylate, or butyl acrylate. The effect of PU/PAR composition and the cross-linking density in the PAR domain as well as in the PU domain has been studied in terms of density, mechanical, and dynamic mechanical properties in addition to the drying rate and the contact angle of the dispersion cast film with water. A high degree of interpenetrations was verified by mechanical properties showing positive deviation with a maximum from the additivity. In addition, incorporation with acrylate polymers having low glass-transition temperatures effectively augmented the hydrophobicity without sacrificing the elasticity of the original PUs. In addition, the acrylate monomers were polymerized by UV irradiation to significantly reduce the reaction time.

Strain rate dependence of fracture in a rubber-toughened epoxy system

The toughening mechanisms in rubber-modified epoxies appear to be viscoelastic in nature since their fracture behavior is dependent on loading rate. This behavior has been studied in detail and modeled for only one system, a model toughened epoxy often used in research work. The present study examines the loading rate effect for a new material based on acrylic rubber by measuring the fracture energy in constant cross-head speed tests conducted over a wide range of speeds. As expected, decreasing the loading rate produced an increase in toughness. Just as in the previous studies, the fracture energies could be modeled with a power law relationship when the loading rate was characterized by the time of failure. Moreover, the parameters involved in the model are quite consistent with the earlier results. For most rates, the behavior was approximately linear elastic with little or no r-curve behavior. Below a critical rate, however, there was a transition to ductile failure with a large r-curve and very high fracture energies. The transition is very sudden which may help explain why some previous studies have observed this effect while others have not.

Molecular design of damping rubber based on polyacrylate‐containing silicone

AbstractA series of damping rubbers based on poly(meth)acrylate and poly(meth)acrylate‐containing silicone rubbers has been prepared. The dynamical mechanical properties were evaluated by using a dynamic mechanical viscoelastometer (DMA). A detailed investigation is reported on the relationship of the damping capability of the poly(meth)acrylate rubbers with their composition and macromolecular architecture. Also discussed is the effect of two kinds of silicone elastomers on the damping performance of the polyacrylate‐containing silicone rubber. The results indicate that, in vulcanized rubber systems, both statistical copolymerization for multiple monomers and blending between immiscible polymers with close Tgs facilitate broadening the glass transition peaks. Furthermore, the molecular design is quite an effective approach in which the multiple monomers whose polymers have a ladder‐changing Tg are used to synthesize the damping rubber with the broad effective functional area. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 746–751, 2002

Properties of polymer-modified cement mortar using pre-enveloping method

A new method, pre-enveloping sand with polymer, was adopted to make polymer-modified cement mortar (PCM). In the research, two kinds of latex, i.e., styrene acrylate rubber and styrene butadiene rubber, were used. The experimental results of physical and mechanical tests showed that, at the same level of polymer cement ratio, pre-enveloping method was better than normal method regarding the performance of the resulted composite. Moreover, in the condition of relatively low addition of polymer, the improvement of physical and mechanical properties, especially the resistance to cycling of freezing–thawing, by the pre-enveloping method was more significant. Additionally, it was found that styrene butadiene rubber can improve the fluidity of the mortar, and mortar with styrene acrylate rubber can maintain the same fluidity as the control sample by adding small quantities of a superplasticizer. Styrene acrylate rubber had no water-reducing ability by itself.

Morphology, mechanical and thermal behavior of acrylate rubber/fluorocarbon elastomer/polyacrylate blends

Novel thermoplastic elastomers derived from binary and ternary blends of polyfunctional acrylates, acrylic rubber (ACM) and fluorocarbon rubber (FKM) were analyzed by using Transmission Electron Microscopy (TEM), Differential Scanning Calorimetry (DSC), Dynamic Mechanical Thermal Analysis (DMTA) and mechanical tests. TEM revealed the presence of a single-phase structure for both acrylate rubber/fluorocarbon elastomer (ACM/FKM) and ACM/polyacrylate binary blends. Increase of FKM concentration in the ACM/FKM/polyacrylate ternary blend resulted in phase separation of FKM from the ternary blend. The FKM formed a dispersed phase with polynodal particle distribution and irregular shape ranging from ellipsoidal to highly elongated form with inclusion of ACM. The FKM/polyacrylate binary blend showed complete phase separation. Ageing of the blend increased the domain size of the dispersed phase. Differential scanning calorimetric (DSC) and DMTA studies showed no major changes in the Tgs of individual polymers in the blend, although the peak tan δ values were affected on changing the composition of the blends. Vulcanization of the thermoplastic elastomer (TPE) changed the phase morphology with increase in particle size. There is a distinct difference in morphology of statically and dynamically vulcanized blends.

Novel Thermoplastic Elastomers from Fluorocarbon Elastomer, Acrylate Rubber and Acrylate Plastics

Views Icon Views Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Cite Icon Cite Search Site Citation M. Abdul Kader, Anil K. Bhowmick; Novel Thermoplastic Elastomers from Fluorocarbon Elastomer, Acrylate Rubber and Acrylate Plastics. Rubber Chemistry and Technology 1 September 2001; 74 (4): 662–676. doi: https://doi.org/10.5254/1.3544965 Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest Search

Reactive blending of functionalized acrylic rubbers and epoxy resins

AbstractA high molecular weight acrylonitrile/butadiene/methacrylic acid (Nipol 1472) rubber is chosen to control processability and mechanical properties of a TGDDM (tetra glycidyl diphenyl methane) based epoxy resin formulation for aerospace composite applications. The physical blend of rubber and epoxy resin, achieved by dissolution of all the components in a common solvent, forms a heterogeneous system after solvent removal and presents coarse phase separation during cure that impairs any practical relevance of this material. A marked improvement of rubberepoxy miscibility is achieved by reactive blending (‘pre‐reaction’) the epoxy oligomer with the functional groups present in the rubber. The epoxy‐rubber ‘adduct’ so obtained appears as a homogeneous system at room temperature and also after compounding with the curing agent. Depending on the nature and extent of interactions developed between the rubber and the epoxy resin during ‘pre‐reaction,’ materials with different resin flow characteristics, distinctive morphologies and mechanical properties after curing were obtained. The effect of ‘pre‐reaction’ on the resin cure reaction kinetics has been also investigated.

Acoustic analysis of composite soft materials. I. Characterization of the core and boundary layer from compressibility of core/shell particles dispersed in poly(vinyl chloride)

The sound velocity of butyl acrylate rubber particles modified by poly(methyl methacrylate) in poly(vinyl chloride) was measured as a function of particle concentration. A model for estimating the adiabatic compressibility of the particle and the boundary layer was proposed. From the model, the partial specific adiabatic compressibility of the particles and the rubber core were evaluated. The adiabatic compressibility of the rubber core was estimated as 3.82 × 10−10 Pa−1. The adiabatic compressibility of the poly(methyl methacrylate) shell is discussed based on the modified model. The study indicates that the shell, including the boundary layer between butyl rubber and poly(methyl methacrylate), is perturbed by the butyl acrylate molecules and is so soft as to be comparable to the rubber. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 2089–2094, 2001

Acoustic analysis of composite soft materials. I. Characterization of the core and boundary layer from compressibility of core/shell particles dispersed in poly(vinyl chloride)

AbstractThe sound velocity of butyl acrylate rubber particles modified by poly(methyl methacrylate) in poly(vinyl chloride) was measured as a function of particle concentration. A model for estimating the adiabatic compressibility of the particle and the boundary layer was proposed. From the model, the partial specific adiabatic compressibility of the particles and the rubber core were evaluated. The adiabatic compressibility of the rubber core was estimated as 3.82 × 10−10 Pa−1. The adiabatic compressibility of the poly(methyl methacrylate) shell is discussed based on the modified model. The study indicates that the shell, including the boundary layer between butyl rubber and poly(methyl methacrylate), is perturbed by the butyl acrylate molecules and is so soft as to be comparable to the rubber. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 2089–2094, 2001

Rheological and Mechanical Properties of Gum and Filled Blends of Acrylate Rubber and Fluororubber

Rheological, mechanical and dynamic mechanical thermal properties of gum and filled acrylate rubber (ACM), fluoro rubber (FKM) and their blends were studied. The systems exhibited pseudo plastic flow behaviour. The shear viscosity of the blends decreased with higher concentration of ACM. There was little effect of temperature on the viscosity of the blends at different shear rates. Addition of filler to the 50/50 (w/w) ACM/FKM blend increased the shear viscosity. The equilibrium die swell decreased with increasing loading of carbon black and was affected by the filler type. A linear generalized relationship was obtained between die swell and maximum recoverable deformation. The activation energy of the melt flow process decreased with an increase in shear rate for all the gum and filled systems except neat ACM, where there was a slight increase in activation energy. The mechanical properties of the filled compounds improved linearly with filler loading. Tan δ peak temperature did not change with filler loading although the values of tan δmaximum decreased. The storage modulus of the blends increased with increasing filler loading, indicating the presence of polymer filler interactions.

Phase Modification of Acrylate Rubber/Chlorinated Polypropylene Blends by a Hindered Phenol Compound

The dynamic mechanical properties and the morphologies for the binary blends of acrylate rubber (ACM) and chlorinated polypropylene (CPP) with 3,9-bis[1,1-dimethyl-2{β-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionyloxy}ethyl]-2,4,8,10-tetraoxaspiro[5,5]-undecane (AO-80), and their ternary systems were investigated. The AO-80 distribution to each phase of an immiscible ACM/CPP blend was studied in term of a shift in glass-transition temperature. It was found that when the AO-80 content is lower than 30% the AO-80 molecules are preferentially dissolved to an ACM continuous phase, whereas as the AO-80 content increases, a part of AO-80 molecules are incorporated to the blend interfaces, and then to the domains of CPP. In addition, the reduction in the domain size of CPP due to adding AO-80 was also observed. A ternary blend of ACM/CPP (7:3) with AO-80 (35%) showed a novel tan δ peak between two peaks corresponding to ACM and CPP. This peak is attributed to an interfacial layer where a super-molecular network is formed. As a result, a ternary blend of ACM/CPP with AO-80 was found to be a very good damping material.

Effect of Interchain Crosslinking on the Shrinkability of Blends Consisting of Low-Density Poly(ethylene) and Ethylene Acrylic Rubber

Two samples have been prepared to study the effect of interchain crosslinking on the heat shrinkability of the blends. In the first sample low-density poly(ethylene) is blended with ethylene acrylic rubbert while in the second one glycidyl acrylate-grafted low-density poly(ethylene) is bleded with ethylene acrylic rubber. it is revealed that interchain crosslinking in the glycidyl acrylate grafted low-density poly(ethylene) and ethylene acrylic rubber improves the heat shrinkability in the second sample.

Effects of a hindered phenol compound on the dynamic mechanical properties of chlorinated polyethylene, acrylic rubber, and their blend

AbstractThe dynamic mechanical properties of binary hybrids of chlorinated polyethylene (CPE) and acrylic rubber (ACM) with 3,9‐bis{1,1‐dimethyl‐2[β‐(3‐tert‐butyl‐4‐ hydroxy‐5‐methylphenyl)propionyloxy]ethyl}‐2,4,8,10‐tetraoxaspiro[5,5]‐undecane (AO‐80) and their ternary hybrids were investigated. The addition of AO‐80 was successful in tailoring the damping profile. The ACM/AO‐80 hybrids show only one relaxation, which is larger than that of pure ACM, whereas for the CPE/AO‐80 hybrids, one novel relaxation appears above the glass‐transition temperature of CPE. In the case of CPE/AO‐80/ACM, a supramolecular network was formed by a crosslink due to hydrogen bonding. The replacement of a part of CPE by ACM increased the value in the middle of two peaks. The AO‐80 molecule, which is a bifunctional hydrogen‐bonding acceptor, was found to act as a compatibilizer. In addition, in such ternary hybrids, the tan δ value in the middle of the two peaks was found to be proportional to the slope of the E′ curve at an identical temperature. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 2468–2473, 2001

Effects of composition and temperature on extrudate characteristics, morphology, and tensile properties of acrylic rubber–blended PVC

AbstractPoly(vinyl chloride) was blended with acrylic rubber over a range of compositions (5–40 wt % of the rubber), using a twin‐screw extruder. Morphological properties of the blends were investigated as a function of rubber content and blending temperature, using a scanning electron microscopy. The mechanical properties of the blends were determined by a tensile test. Smooth extrudates were obtained at the blending temperature of 155°C. At a higher blending temperature (195°C), greater die swell ratio and/or melt‐fractured extrudates were observed, depending on the rubber content. Miscible blends were obtained at low rubber contents (5–10 wt %). A dispersed particle morphology was observed from the extrudates containing the rubber content of 20–40 wt %, at 195°C. The ultimate tensile stress (UTS) and modulus of the blends decreased with the rubber content. The maximum tensile toughness was obtained for the blend with a rubber content of 20%, at a blending temperature of 155°C. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 2523–2534, 2001

SPECIALTY POLYBLEND SYSTEMS OF POLYURETHANE RUBBER AND ETHYLENE ACRYLIC RUBBER (PEROXIDE CURE)

Polyblends of polyurethane (AU) and ethylene acrylic rubber (Vamac) have been prepared using two different blending techniques to develop new polymeric materials. The overall study was carried out using DCP as a curative, where both the phases were vulcanized. The state of cure gradually decreased with the increment of Vamac content. Preblended sample hardness and modulus followed the same trend with state of cure, but the tensile strength and elongation at break increased with increase of the Vamac dose. Preheated preblended samples follow the same trend. IR spectral analysis of the AU/Vamac blend, without any curative, revealed that interchain crosslinking is formed between two elastomers on heat treatment. High-temperature DSC/TGA suggested the enhanced thermal stability of the preheated preblended sample. From SEM study, it is observed that the preheating of the preblend restricts the extraction of single phase in solvents due to the formation of interchain crosslinks.

アクリルゴム/有機フィラー系ハイブリッド制振材料の物性

The damping behavior of organic hybrids prepared from acrylic rubber(AR) and the functional organic filler were investigated. 4, 4', -Thio-bis (3-methyl-6-tert-butylphenol) (F1) and Pentaerythritol tetrakis [3-(3, 5-di-tert-butyl-4-hydroxyphenyl) propionate] (F2) were used as the functional organic molecules. DSC and DMA indicate the miscibility between AR and organic fillers, since these hybrids have a single glass-transition temperature. With increasing filler content, the height of tan δ peak increases accompanying a shift of the peak position to the higher temperature. It was found that Kwei's equation can well describe the DSC result, and the parameter q was calculated to be 46 for AR/F1 and-15 for AR/F2. These results suggested that the AR-F1 interaction is much stronger than the AR-F2. FT-IR study further confirmed that there is a strong hydrogen bond between AR and F1. As a result, the stability of damping properties for AR/F1 is quite good, whereas for AR/F2, it is poor due to a gradual crystallization of F2 in AR matrix.

有機めっき処理金属とアクリルゴムとの直接加硫接着

A novel technique for the direct adhesion between acrylic rubber (ACM) and metals, such as iron, nickel and stainless steel SUS 304 during vulcanization was developed. The metals are first plated with thin polymer films through the electrochemical polymerization of 6-diallylamino-1, 3, 5-triazine-2, 4-dithiol monosodium (DAN), and then adhered directly to acrylic rubber during vulcanization. The modification of metal surface has been also called polymer plating compared with the traditional metal electroplating. The thickness of the polymer film has a significant effect on the peel strength of the adherend of polymer plated metal to ACM. The peel strength of the adherend increases rapidly with the film thickness within about 25nm, and beyond the thickness, maintains enough peel strength showing the rubber cohesive failure with 100% rubber coverage. The peel strength of the adherends decreases with the increase of the amounts of the curing agents but shows rubber cohesive failure in the normal compounding amounts. The curing temperature and time of the rubber have only a little effect on the peel strength of the adherend. The adherend has excellent heat aging resistance and oil resistance.