Acrylic Rubber Research Articles

Poly(vinylidene fluoride)-acrylic rubber partially miscible blends: Crystallization within conjugated phases induce dual lamellar crystalline structure

The miscibility of melt mixed poly(vinylidene fluoride)(PVDF)/acrylic rubber(ACM) blends and the crystal morphology of PVDF in the blends over the whole composition range were investigated by dynamic mechanical analysis (DMA), optical microscopy(OM), Fourier transform infrared spectroscopy (FTIR), small angle X-ray scattering (SAXS), differential scanning calorimeter (DSC), and scanning electron microscopy (SEM). DMA analysis revealed that PVDF is partially miscible within the PVDF rich blends whereas it is fully miscible in the ACM rich blends. Phase diagram was obtained for α-PVDF/ACM blends using OM and DSC measurements. FTIR study showed that PVDF crystallizes in α form in the blends. Dendritic spherulites were observed for the miscible blends as well as for the ACM rich phase in partially miscible blends. Spherulite growth rate in miscible blends was analyzed by Lauritzen Hoffman equation. Blending with ACM increased free energy of folding for PVDF lamella. Lamellar thickness calculated for two conjugated phases in the partially miscible blends showed different values in agreement with the two peaks observed in SAXS profiles of partially miscible blends, suggesting dual lamellar crystal structure.

Poly(vinylidene fluoride)–acrylic rubber partially miscible blends: Phase behavior and its effects on the mechanical properties

A phase diagram of poly(vinylidene fluoride) (PVDF) and acrylic rubber (ACM) was plotted, and the effects of the extent of miscibility on the mechanical properties of the polymer blends were examined. A compressible, regular solution model was used to forecast the phase diagram of this blend. The model prediction, the lower critical solution temperature (LCST) over the upper critical solution temperature (UCST), was done qualitatively according to the experimentally determined phase diagram by differential scanning calorimetry (DSC), optical microscopy, and rheological analysis. These experimental methods showed that this system was miscible in ACM‐rich blends (>50% ACM) and partially miscible in PVDF‐rich blends. A wide‐angle X‐ray diffraction study revealed that PVDF/ACM blends such as neat PVDF had a characteristic α‐crystalline peak. The partially miscible blends displayed up to 350% elongation at break; this was a significant increment of this parameter compared to that of neat PVDF(20%). However, the miscible blends showed elongation of up to 1000% [again, a remarkable increase compared to chemically crosslinked ACM (220%)] and displayed excellent mechanical properties and tensile strength and a large elongation at break. For the miscible and partially miscible blends, two different mechanisms were responsible for this improvement in the mechanical properties. It was suggested that in the partially miscible blends, the rubbery depletion layer between the spherulite and the conventional rubber cavitations mechanism were responsible for the increase in the elongation at break, whereas for the miscible blends, the PVDF spherulite acted as a crosslinking junction. The stretched part of the tensile samples in the partially miscible blends showed characteristic β‐crystalline peaks in the Fourier transform infrared spectra, whereas that in the miscible blends showed α‐crystalline peaks. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 1247‐1258, 2013

Structures and morphologies of in situ polymerized blends of PMMA and ASA

AbstractBlends of poly(methyl methacrylate), PMMA, and the elastomer ASA, a graft copolymer based on poly(acrylonitrile‐co‐styrene) (SAN) and acrylic rubber, were prepared by in situ polymerization and characterized according to structural, mechanical, thermal, and morphological properties. The polymerization conditions, such the presence or absence of a chain transfer agent, stirring and an inert atmosphere, influence the morphological and structural properties of the blends. In spite of the evidences of the partial miscibility between PMMA and SAN phase of the ASA, the blends are heterogeneous and present a complex morphology. The morphology of some PMMA‐ASA blends is made up of an elastomeric dispersed phase in a glassy matrix, with a possible inclusion of the matrix in the elastomeric domains. The selective extraction of the blend components and infrared spectroscopy showed that crosslinking and/or grafting reactions occur on ASA chains during MMA polymerization. The syndiotacticity of PMMA obtained in the presence of ASA increases with the amount of ASA, due to possible interactions between the carbonyl groups of PMMA and the nitrile or phenyl groups of the SAN copolymer. The mechanical properties of the blends were influenced by the compositions of the blends and mainly by the conditions of polymerization. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013

폴리에스터계 동적가교물의 고무함량 및 고무종류에 따른 물성

E-TPE(Engineering Thermoplastic Polyether Ester)는 Ester 관능기를 갖는 Elastomer 소재로서 리사이클이 가능하며 빠른 가공성을 지닌다. 또한 경량성이 뛰어나 자동차의 경우 연비향상에 도움을 주는 친환경 소재로 부각되고 있다. 고무와 엔지니어링 플라스틱의 특성을 모두 가지고 있는 E-TPE는 사용 가능한 온도영역이 넓고, 내열성 및 내유성이 우수하여 자동차 부품소재분나 전기전자분야의 신소재로 주목받고 있으나 국내에서는 원천기술이 부족하여 전량 수입에 의존하고 있는 실정이므로 연구개발이 시급하다. 본 연구에서는 하드 세그먼트로 폴리에스터계(TPEE)를 base로 하여 소프트 세그먼트로 Ethylen-prophylene-Copolymer와 CSM(Choloro sulphonated polyethylene Rubber), VAMAC(Ethylene Acrylic Rubber), NBR(Acrylonitrin Butadiene Rubber)의 탄성체를 1,3-Phenylene-bisoxazoline 가교제로 동적가교 시켜 함량과 첨가된 고무에 따른 물성을 관찰하였다. 그 결과 NBR 첨가된 동적가교물의 물성이 다른 고무에 비해 내열성 및 내유성 향상에 되었음을 확인하였다. E-TPE (Engineering Thermoplastic Polyether Ester) was Ester Elastomer with functional groups as recycling and fast processability. In addition, if the car's lightweight enough to highlight eco-friendly materials that help to improve fuel economy has become. Have all the attributes of the rubber and engineering plastics E-TPE the available temperature area is spacious, heat resistance and oil resistance is excellent but getting attention as a new material in the field of auto parts in the field of electrical and electronic domestic depends entirely on imports by the lack of core technology and has been research and development is urgently needed. In this study, the hard segments, polyester (TPEE) as the base soft elastomers of the segments Ethylen-prophylene-Copolymer and CSM (Choloro sulphonated polyethylene Rubber), VAMAC (Ethylene Acrylic Rubber), NBR (Acrylonitrin Butadiene Rubber), 1, 3-Phenylene-bisoxazoline is dealing with Dynamic Vulcanized by content and added rubber properties, thermal variation observed. As a result, the properties of the dynamic vulcanization with NBR compared to other rubber heat resistance and oil resistance is on the increase.

Peel strength and fatigue resistance of AEM rubber–polyester fabric composites (II); application of hydrated silica, resorcinol, and hexamethoxymethylmelamine (HRH) system and double dip system

In this study, the adhesion between ethylene methyl acrylic (AEM) rubber and polyester fabric treated with double dip system was evaluated and the fatigue resistance of AEM rubber–polyester fabric composites was evaluated. When determined the latex of resorcinol-formaldehyde-latex solution having high compatibility with AEM rubber, chloroprene rubber latex where the cross-linking reaction was possible with amine cross-linking agent showed the highest bond strength in the adhesion of the AEM rubber–polyester fabric composites. The adhesion of AEM compound applying both RF-resin and hexamethoxymethylmelamine which are the adhesion promoters showed the increase of approximately 41.7% compared to the compound without applying them. The compound applying adhesion promoters and carbon black (10 phr)/silica (20 phr) showed the increased adhesion of approximately 21.7% than the compound applying adhesion promoter and carbon black (30 phr). The bond strength of the AEM rubber–polyester fabric composite was excellent when the least amount of cross-linking agent and accelerator were applied to the AEM compound. As the results of fatigue test, the compound with plasticizer and adhesion promoters showed lower accumulated crack length than the compound with adhesion promoters only, and the compound with adhesion promoter and carbon black/silica filler blend showed the lowest crack number and accumulated crack length than the above two compounds, so it can be judged that its fatigue resistance is superior.

Peel strength and fatigue resistance of AEM rubber–polyester fabric composites (I): application of isocyanate adhesive solution

In this research, the adhesion between ethylene methyl acrylic (AEM) rubber and polyester fabric treated with isocyanate and the fatigue properties of the AEM rubber–polyester fabric composites were examined. Experiments were conducted according to the concentrations of isocyanate adhesive solution in order to determine the optimum concentration of the adhesive agent and the results showed that adhesion was the most superior when 14% solution was applied and this was also confirmed by Scanning electron microscope morphology. Moreover, the impregnated polyester fabric was treated at 120, 170, 200, and 230 °C and peel test was conducted in order to determine the optimum curing condition. The results showed that adhesion was the most superior when the polyester fabric was cured for 2 min at 230 °C. It was judged that this resulted from the network structure of isocyanate and the formation of carbodiimide structure at the curing temperature of 230 °C. Comparing to the fatigue properties of the rubber–fabric composites from single dip system and the double dip system, the crack number and the accumulated crack length, the crack propagation was lower when the double dip system was applied. This resulted from the flexibility of the interphase of the polyester fabric–AEM rubber composites by the application of resorcinol-formaldehyde-latex (RFL).

Compatibilization efficiency of carboxylated nitrile rubber and epoxy pre-polymer in nitrile/acrylic rubber blends.

An investigation has been made of the effects from a compatibilizer, viz. carboxylated nitrile rubber (XNBR), on several properties of nitrile rubber (NBR) and acrylic rubber (ACM) blends, including curing characteristics, mechanical, dynamic mechanical and dielectric properties. The presence of XNBR until 10 phr resulted in an improvement of the ultimate tensile properties, especially elongation at break. The mechanical properties associated to the volume fraction of rubber in the network (Vr) and torque values suggest the co-vulcanization phenomenon imparted by the compatibilization. The oil resistance of NBR/ACM (50:50 wt. (%)) blends (compatibilized and non compatibilized) was similar to that observed for pure ACM and significantly higher than NBR. The addition of small amounts of epoxy pre-polymer in combination with XNBR resulted in an additional improvement of the tensile properties. The dynamic mechanical and dielectric properties of the blends were also investigated. The loss modulus values of the compatibilized blends were significantly lower indicating an increase of the elastic characteristics. All blends presented two dielectric relaxation peaks confirming the heterogeneity of the compatibilized blends

New damping materials by fabrication of ACM/PVC alloy into hollow fibers

AbstractNew acrylic rubber hollow fiber damping materials were successfully produced by dry–wet spinning technique. The effect of polymer concentration and blending ratio on ACM/PVC hollow fiber were investigated. The results showed that the tensile strength increased with the increase of polymer content and decreased with the decrease of blending ratio. DMA revealed that varying the size of inner diameter, the loss tangent (tan δ) would change. FTIR proved certain interactions among them. In addition, the position of peak of the glass transition temperature not only shifted to a higher temperature with the increase of PVC content, but also its temperature range of tan δ > 0.3 was 40–65°C, inferring that ACM/PVC mixture is a promising damping‐material. The outer skin and inner skin structure of ACM/PVC hollow fiber by SEM were different from that used in water treatment due to the differences between materials. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013

Electroactive perovskite lead zirconate particles embedded in an acrylic elastomer

AbstractLead zirconate was synthesized via the sol-gel process and calcined at 300°C for 1 h to obtain a Perovskite structure of an orthorhombic form. SEM micrographs indicate that the lead zirconate particles are moderately dispersed in a solid acrylic rubber, AR71. Without an electric field, the particles merely act as a dielectric filler that can absorb and store additional stress. Under electrical field, particle-induced dipole moments are generated, leading to the interparticle interactions, thus creating a substantial increase in the storage modulus. At the small volume fraction of lead zirconate particles of 0.02 embedded in the elastomer matrix, the electrical conductivity increases dramatically by two orders of magnitude. At the volume fraction of merely 0.0002, the storage modulus, or the composite rigidity, increases by a factor of two as the electric field strength is varied from 0 to 2 kV/mm.

Highly efficient toughening effect of ultrafine full-vulcanized powdered rubber on poly(lactic acid)(PLA)

A unique ultrafine full-vulcanized powdered ethyl acrylate rubber (EA-UFPR) was used as the toughening modifier for poly (lactic acid) (PLA). Largely improved tensile toughness was successfully achieved with the incorporation of only 1 wt% EA-UFPR, while the tensile strength and modulus of the blends were almost the same as pure PLA. The highly efficient toughening of PLA by UFPR is mainly ascribed to the strong interfacial interaction between PLA and UFPR and good dispersion of UFPR particles in PLA matrix. Our work provides an effective toughening method to largely improve the mechanical properties of PLA without sacrificing its stiffness, which is very important for the wide application of PLA materials.

자동차용 고무호스의 진동 절연성능 향상에 관한 연구

We considered an approach in terms of materials for improvement of insulation performance of vehicle rubber hoses. Ethylene propylene rubber(EPDM) for heater hoses in cooling system and acrylic rubber(AR) for intercooler hose in intake system were chosen for mixing for the vibration and noise performance. We modified EPDM and AR through changing compound of base polymer, reinforcement fillers and additives. Dynamic mechanical analysis(DMA) was used to measure viscoelastic properties such as shear modulus and loss factor($tan{\delta}$). Vehicle acceleration test was also conducted to observe indoor changes in insulation performance of hoses.

Mechanical properties and crystallization of Poly(L-lactide) films with several percents of ACR nanoparticles

The mechanical properties measurement of Poly(L-lactide) (PLLA) films modified by adding just several percents of acrylic rubber (ACR) nanoparticles showed that the elongation at break and tensile strength increased obviously by comparing with neat PLLA film. The crystallization behavior of modified PLLA blend films was characterized by Differential Scanning Calorimetry (DSC) and Wide-angle X-ray diffraction (WAXD); it was found that the crystallization degree of PLLA was improved with small amount of ACR nanoparticles. The results indicate that ACR nanoparticles not only take the role of the toughening agents for PLLA films, but also increase the crystallization degree of PLLA as nucleation agents, which contribute to the enhancement of the tensile strength and modulus of PLLA films.

Cold‐crystallization behavior of poly(L‐lactide)/ACR blend films investigated by in situ FTIR spectroscopy

AbstractThe cold crystallization behavior of poly (L‐lactide) (PLLA) blend films modified by small amount of acrylic rubber particles (ACR) have been investigated by in situ Fourier‐transform infrared (FTIR) spectroscopy. During the isothermal cold crystallization, the crystallization rate of PLLA is greatly improved with addition of only 1 wt % ACR. However, for PLLA with 8 wt % ACR, the crystallization rate is slower than that of neat PLLA. The relative crystallinity of PLLA with the addition of 1–5 wt % ACR is obviously higher than that of the neat PLLA. For the PLLA blend film with 3 % ACR, the relative crystallinity reaches a maximum. It was found that the addition of ACR particles below 5% accelerated the cold crystallization nucleation process and made the cold‐crystallization rate of PLLA/ACR be quicker than that of neat PLLA. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013

Mechanical and thermal properties of FPM/PHACM/ACM blends

The bisphenol AF/benzyltriphenylphosphonium chloride (BPP) vulcanization system is the most commonly used fluoroelastomer (FPM) vulcanization system. In this article, polyphenol hydroxy acrylic rubber (PHACM) was prepared through a two-step reaction: grafting polymerization and condensation. The properties of FPM/PHACM/acrylic rubber (ACM) blends including vulcanization properties, mechanical properties, aging properties, oil resistance and thermal properties were studied. The results of vulcanization properties show that under the bisphenol AF/BPP vulcanization system, the FPM can achieve covulcanization with PHACM without adding bisphenol AF and get longer scorch time than that of FPM with the same level of bisphenol AF, which means that FPM/PHACM/ACM blends have better processability and curing security. Furthermore, the blends show better mechanical properties and thermal stability. The results of differential scanning calorimeteric analysis show that the FPM and PHACM achieve co-cross-linking and have good compatibility. The glass transition temperature ( Tg) of the blends has been reduced to −18.57°C, which is 8.33°C lower than that of pure FPM, when the content of blends is equal to 100/100. The scanning electron microscopy shows that PHACM can improve interfacial adhesion between the FPM and ACM.

A direct method for the vulcanization of acrylate rubber through in situ coordination crosslinking

In this work, a straightforward method of vulcanizing acrylate rubber (AR) was explored via the introduction of in situ coordination crosslinking. An inorganic metal salt, copper sulfate (CuSO4), was mechanically mixed with AR and heat pressed to prepare a novel crosslinkable AR/CuSO4 composite. The determination of the coordination bonding between the ester groups of AR and copper (II) ions was performed with Fourier transform infrared spectroscopy based on the red shifts of the ester group absorption bands and the disappearance of the coordinated sulfate absorption bands, as well as by electron spin resonance based on the changes in the g-factor of copper (II). The crosslinking procedure of the composite was investigated through dynamic mechanical analysis. In addition, the extent of the crosslinking of the AR/CuSO4 composites was evaluated by observing the swelling behaviors. Scanning electron microscopy was used to investigate the morphology of the composite. The vulcanizates exhibited improved physical properties with high elongation at break due to exchange reaction between the ester groups of AR and CuSO4. An inorganic metal salt, copper sulfate (CuSO4), was mechanically mixed with acrylate rubber (AR) and heat pressed to prepare a novel crosslinkable AR/CuSO4 composite. The coordination reaction between the ester lateral groups and the copper (II) ions was carried out at elevated temperatures. A straightforward method of vulcanizing AR was explored via the introduction of in situ coordination crosslinking.

Study of the orientation‐controlled damping temperature based on selective distribution of oligo‐phenol in acrylate rubber/chlorinated butyl rubber blends

AbstractIn this paper, a series of composites containing of the oligo‐phenol (produced by reacting of 4‐methyl‐phenol with dicyclopentadiene and isobutylene (MPDI)) as organic fillers, and chlorinated butyl rubber (CIIR)/acrylate rubber (AR) as matrix were prepared by melting blending method. The selective distribution phenomenon of organic fillers in the matrix and the damping properties of AR/CIIR/MPDI composites were characterized by DMA, DSC, FT‐IR and SEM, respectively. The results showed that MPDI could form hydrogen bond with AR more easily than with CIIR, which resulted in MPDI dispersing preferentially in AR phase in CIIR/AR composites. And the selective dispersion of MPDI caused that the damping temperature range was orientedly broadened towards the high temperature. Specially, with the content of MPDI increased to 10 wt% in AR/CIIR marix, only the Tg of AR in AR/CIIR composites shifted to higher temperature, which reached to 55.2°C, while the Tg and Tll of CIIR in AR/CIIR composites kept almost unchanged. Otherwise, the temperature range of AR/CIIR/MPDI was expanded to 100.2°C with the tan δ > 0.3. Therefore, it was expected as a promising way to orientedly broaden damping temperature range according to the selective distribution of organic additives in binary systems. POLYM. COMPOS., 2012. © 2012 Society of Plastics Engineers

Enhancement of thermal aging performance and oil resistance of acrylic rubber vulcanisates by adding devulcanised ground fluoroelastomer ultrafine powder as functional filler

In this study, devulcanised ground fluoroelastomer (FKM) ultrafine powder with the sol fraction of 19·8% and the average particle size of ∼1 μm or less was successfully prepared by solid state mechanochemical milling at ambient temperature. This reclaimed FKM can be used as a low cost but effective functional additive for enhancing the thermal aging performance and oil resistance of acrylic rubber (ACM) vulcanisates. The mechanical properties of the ACM–ground FKM blends were significantly improved through the mechanochemical pretreatment of FKM. The ACM–devulcanised FKM blends showed similar curing behaviours and enhanced mechanical properties as compared to pure ACM compound. As devulcanised FKM content increased, the tensile strength of thermal aged (150°C×72 h) ACM vulcanisates increased from 3·9 to 6·4 MPa, by ∼65%; while elongation at break increased from 42·8 to 106·1%, by ∼1·5 times. The ACM–devulcanised FKM blends also exhibited better oil resistance than pure ACM. Dynamic mechanical analysis and scanning electron microscopy–energy dispersive spectroscopy confirmed the well miscibility and superior dispersion of devulcanised FKM in ACM matrix.

선택된 단량체와 가교제에 의한 아크릴고무의 물성 변화에 관한 연구

주단량체로 에틸 아크릴레이트, 부틸 아크릴레이트, 메톡시에틸 아크릴레이트, 가교 단량체로 글리시딜 메타아크릴레이트를 유화중합하여 아크릴고무를 제조한 후, 가교제로써 2,2-bis[4-(4-aminophenoxy)phenyl]propane를 첨가하여 고무컴파운드를 제조하였다. 주단량체의 조성에서 에틸 아크릴레이트의 함량이 증가하면 내열성이 증가하는 경향을 보였는데 이는 아크릴고무의 유리전이온도가 감소되었기 때문이다. 또한 에틸 아크릴레이트의 에스테르 그룹 농도가 3개의 주단량체 중 가장 높기 때문에 에틸 아크릴레이트 함량이 증가할수록 내유성이 향상되었다. 2,2-Bis[4-(4-aminophenoxy)phenyl]propane의 함유량에 따른 영향은 2 phr 첨가까지 인장강도와 신장율은 증가하지만, 그 이상의 첨가에서는 가교밀도의 증가에 따른 점성과 탄성이 감소하여 그 값들이 감소하였다. Acrylic rubber was synthesized using ethyl acrylate. butyl acrylate, methoxyethyl acrylate as main monomers and glycidyl methacrylate as cure site monomer by emulsion polymerization. Rubber compound was made by adding 2,2-bis[4-(4-aminophenoxy)phenyl]propane as crosslinking agent. Increase of ethyl acrylate content in the main monomer ratio resulted in enhancement of heat resistance due to decrease of glass transition temperature in acrylic rubber. And also oil resistance was increased with increasing content of ethyl acrylate because ethyl acrylate has the highest ester concentration in the three main monomers. With content of 2,2-bis[4-(4-aminophenoxy)phenyl]propane, both tensile strength and elongation were increased until 2 phr, but in higher content than that, they decreased owing to reduction of viscosity and elongation by increase of crosslinking density.

Formulation and in vitro evaluation of transdermal drug delivery system for donepezil

The effects of different formulation variables on the transdermal absorption of donepezil were investigated. The permeation of donepezil from various pressure sensitive adhesive matrices was evaluated using flow-through diffusion cell system at 37°C. The penetration of donepezil from the matrices was found to be influenced by the nature of adhesives. 1:1 combination of acrylic rubber hybrid adhesives (Duro-Tak® 87-503A and Duro-Tak® 87-504A) provided good adhesion force and high flux of donepezil. Significant increase in flux was obtained using Brij® 30, Brij® 52, and their combination, as penetration enhancers. Manual assessment using thumb test revealed that patches containing combination of enhancers possessed good adhesive properties. The formulation containing combination of Brij® 30 and Brij® 52, each at the level of 5% v/w with 15% w/w drug load in 1:1 combination of Duro-Tak® 87-503A and Duro-Tak® 87-504A matrix was found to be the best. No significant alteration in morphology and assay values were observed during the physical and chemical stability tests conducted for the study period of 3 months.

S114034 エタノールターボポンプにおけるリップシールの特性評価

Ethanol is recently focused as a new liquid rocket fuel because of its environmental friendliness and easiness to be stored for a long time, though liquid hydrogen and kerosene are commonly used now as liquid fuel for rocket engine. The development of a turbopump for the rocket engine that pressures ethanol to the reaction chamber as liquid fuel is urgently required, but it has not been completed. Particularly, though a performance evaluation of machine components such as shaft seal, bearing and so on is definitely important, there is not enough research on the machine components for operation under ethanol lubrication. We focused the characteristics of lip seals for the turbopump in rocket engine in the study, and designed and developed an experimental apparatus for their performance evaluation under high-pressure and ethanol-lubricated condition. Two kinds of lip seals that made from acrylic rubber and fluorine-containing rubber were prepared. Rotational speed was set constant as 1,000 rpm, and seal pressure was changed from 0.15 to 0.7 MPa for the test. Experimental results showed that friction torque of the lip seals increased with increase in seal pressure because of the increase in the contact pressure between the seal and shaft. Leakage of ethanol from the seal increased until 0.3 MPa as seal pressure, but was almost constant even over 0.3 MPa. We finally concluded that lip seal has a possibility to be applied for the turbopump for ethanol fuel.