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To broaden the knowledge of cytotoxicity of latex in vitro against cultured human cancer cells, this paper examined the latex biocompatibility in vitro via cytotoxicity against a panel of healthy and cancer cells., To broaden the knowledge of cytotoxicity of latex in vitro against cultured human cancer cells, this paper examined the latex biocompatibility in vitro via cytotoxicity against a panel of healthy and cancer cells.

As naphthenic tyre oils increase their market shares as a result of the decline of aromatic extracts, there is an interest in an enhanced understanding of their performance in tyre rubber compounds. We have previously compared naphthenic tyre oils with their Group I based counterparts, i.e. DAE, TDAE and RAE. A reduction of rolling resistance achieved by selecting an appropriate tyre oil often followed. It is well in line with requirements of car manufacturers. In this study we utilized a multiple variables experimental design approach for an enhanced understanding of final rubber properties. It was observed that the approach could be used well. Furthermore, the selected approach can be employed as an efficient tool for compound development and optimization, as well as for the development of novel tyre oils., As naphthenic tyre oils increase their market shares as a result of the decline of aromatic extracts, there is an interest in an enhanced understanding of their performance in tyre rubber compounds. We have previously compared naphthenic tyre oils with their Group I based counterparts, i.e. DAE, TDAE and RAE. A reduction of rolling resistance achieved by selecting an appropriate tyre oil often followed. It is well in line with requirements of car manufacturers. In this study we utilized a multiple variables experimental design approach for an enhanced understanding of final rubber properties. It was observed that the approach could be used well. Furthermore, the selected approach can be employed as an efficient tool for compound development and optimization, as well as for the development of novel tyre oils.

5THR is our special tangential rotor, aimed at improving the quality and productivity of high silica loaded compounds. This rotor was developed by flow analysis, basically experimental and laboratory mixer trials. High silica loaded compounds need a mixing rotor with high energy input and fine temperature control performance. It not only retains the advantages of a tangential rotor’s intake and discharge performance but also has hybrid advantages, such as a similar level of high-energy input and surface area of intermesh rotors. 5THR’s unique sectional shape, wing arrangement and special cooling system make these performances possible. Data will be presented to show this rotor’s versatility with high silica recipes, as well as, tyre and non-tyre carbon black recipes., 5THR is our special tangential rotor, aimed at improving the quality and productivity of high silica loaded compounds. This rotor was developed by flow analysis, basically experimental and laboratory mixer trials. High silica loaded compounds need a mixing rotor with high energy input and fine temperature control performance. It not only retains the advantages of a tangential rotor’s intake and discharge performance but also has hybrid advantages, such as a similar level of high-energy input and surface area of intermesh rotors. 5THR’s unique sectional shape, wing arrangement and special cooling system make these performances possible. Data will be presented to show this rotor’s versatility with high silica recipes, as well as, tyre and non-tyre carbon black recipes.

The objective of the Canaopt project (French joint project) is to study the factors which impact on the consistency of natural rubber. The variability of NR has an important effect on NR compounds properties: Mooney viscosity, cure speed and scorch time, mechanical and dynamic properties (damping and stiffness)., The objective of the Canaopt project (French joint project) is to study the factors which impact on the consistency of natural rubber. The variability of NR has an important effect on NR compounds properties: Mooney viscosity, cure speed and scorch time, mechanical and dynamic properties (damping and stiffness).

The change of dump temperature plays an important role on filler-filler and filler-rubber interactions of silica-filled natural rubber (NR) compounds with the use of bis-triethoxysilylpropyltetrasulfide (TESPT) as a coupling agent. By increasing dump temperature, Payne effect (i.e. filler-filler interaction) decreases, while bound rubber content (i.e. filler-rubber interaction) and Mooney viscosity substantially increase. The optimum properties are achieved when the dump temperature reaches approximately 135oC. The results suggest that two significant reactions simultaneously take place during mixing; 1) the silanization reaction between silica and silane, and 2) the coupling reaction of sulfur contained in TESPT towards rubber molecules. In addition, the inevitably rubber-rubber crosslink can occur due to the sulfur donation of TESPT. The cure characteristic of unfilled NR compound (without elemental sulfur) combined with TESPT and diphenylguanidine (DPG) as an accelerator confirms that free sulfur released from TESPT readily reacts with NR at the temperature as low as 120oC., The change of dump temperature plays an important role on filler-filler and filler-rubber interactions of silica-filled natural rubber (NR) compounds with the use of bis-triethoxysilylpropyltetrasulfide (TESPT) as a coupling agent. By increasing dump temperature, Payne effect (i.e. filler-filler interaction) decreases, while bound rubber content (i.e. filler-rubber interaction) and Mooney viscosity substantially increase. The optimum properties are achieved when the dump temperature reaches approximately 135oC. The results suggest that two significant reactions simultaneously take place during mixing; 1) the silanization reaction between silica and silane, and 2) the coupling reaction of sulfur contained in TESPT towards rubber molecules. In addition, the inevitably rubber-rubber crosslink can occur due to the sulfur donation of TESPT. The cure characteristic of unfilled NR compound (without elemental sulfur) combined with TESPT and diphenylguanidine (DPG) as an accelerator confirms that free sulfur released from TESPT readily reacts with NR at the temperature as low as 120oC.

Dielectric elastomers (DEs) can give rise to surprisingly large deformations by applying an electric field. Because of the lightweight, large strain, and high energy density etc., DEs find many applications in industry such as artificial muscles and sensors. Among various DEs, graphene based DEs have attracted much attention because of its high dielectric constant (k) and unique layered structure. In this study, some new methods were used to improve the electromechanical performance of graphene based DEs. First, we prepared carboxylated nitrile rubber (XNBR) DE with extremely high dielectric constant at quite a low percolation threshold via the directionally distribution of graphene oxide nanosheets (GONS) in XNBR latex and the in-situ thermal reduction of GONS at a low temperature. Second, we prepared GONS-encapsulated carbon nanosphere (GO@CNS) hybrid/XNBR dielectric composite with high k, low dielectric loss and large actuated strain at a low electric filed by latex compounding. Third, we prepared poly (dopamine) encapsulated GONS/elastomer composites with low dielectric loss and improved breakdown strength and actuated strain at a low electric field. The improvement in the electromechanical performance of graphene based DEs facilitates the wider application of DEs., Dielectric elastomers (DEs) can give rise to surprisingly large deformations by applying an electric field. Because of the lightweight, large strain, and high energy density etc., DEs find many applications in industry such as artificial muscles and sensors. Among various DEs, graphene based DEs have attracted much attention because of its high dielectric constant (k) and unique layered structure. In this study, some new methods were used to improve the electromechanical performance of graphene based DEs. First, we prepared carboxylated nitrile rubber (XNBR) DE with extremely high dielectric constant at quite a low percolation threshold via the directionally distribution of graphene oxide nanosheets (GONS) in XNBR latex and the in-situ thermal reduction of GONS at a low temperature. Second, we prepared GONS-encapsulated carbon nanosphere (GO@CNS) hybrid/XNBR dielectric composite with high k, low dielectric loss and large actuated strain at a low electric filed by latex compounding. Third, we prepared poly (dopamine) encapsulated GONS/elastomer composites with low dielectric loss and improved breakdown strength and actuated strain at a low electric field. The improvement in the electromechanical performance of graphene based DEs facilitates the wider application of DEs.

In this study, heat-fusion properties of linear low density polyethylene (LLDPE) and polyethylene terephthalate (PET) with different kinds of compatibilizers, including glycidyl moiety or maleic anhydride moiety in its chemical structure. When LLDPE blended with each compatibilzer was heat fused with PET film, it was found that the peeling energy of LLDPE blended the compatibilizer including glycidyl moiety was much higher than those of neat LLDPE/PET as well as LLDPE blended the compatibilizers including maleic anhydride moiety/PET at any conditions. This is because the functional groups of glycidyl moiety in the compatibilizer can improve the compatibility of LLDPE and PET interface, and as a result, it can enhance the heat-fusion properties of PET/LLDPE. Furthermore, on FT-IR measurement, the absorption assigned to aromatic ester peaks can be observed clearly at the surface of LLDPE after peeling test, indicating that some sorts of PET remained on the surface of LLDPE film with the compatibilizer including glycidyl moiety even after peeling test. Therefore, LLDPE with the compatibilizer including glycidyl moiety can be utilized to produce the heat-fused PET/LLDPE films, In this study, heat-fusion properties of linear low density polyethylene (LLDPE) and polyethylene terephthalate (PET) with different kinds of compatibilizers, including glycidyl moiety or maleic anhydride moiety in its chemical structure. When LLDPE blended with each compatibilzer was heat fused with PET film, it was found that the peeling energy of LLDPE blended the compatibilizer including glycidyl moiety was much higher than those of neat LLDPE/PET as well as LLDPE blended the compatibilizers including maleic anhydride moiety/PET at any conditions. This is because the functional groups of glycidyl moiety in the compatibilizer can improve the compatibility of LLDPE and PET interface, and as a result, it can enhance the heat-fusion properties of PET/LLDPE. Furthermore, on FT-IR measurement, the absorption assigned to aromatic ester peaks can be observed clearly at the surface of LLDPE after peeling test, indicating that some sorts of PET remained on the surface of LLDPE film with the compatibilizer including glycidyl moiety even after peeling test. Therefore, LLDPE with the compatibilizer including glycidyl moiety can be utilized to produce the heat-fused PET/LLDPE films

Natural rubber (NR), a high molecular weight polymer has mainly found applications in automotive industries. Modification of its cis-1,4 polyisoprenic structure by chemical methods can diversify its applications. One-step chemical modification including epoxidation, maleinization and hydrogenation has been known for improvement of oil and heat resistance which are mostly applied in automotive sector. Researches on multi-step chemical modification will be presented for finding new area of applications. The chemical reactions which are epoxidation followed by degradation and addition of photosensitive molecule can be applied for photocurable coating. While the chemical reactions including epoxidation, followed by ring opening reaction can be resulted in a precursor for further step modification of controlled graft copolymerization using atom transfer radical polymerization. Another interesting pathway for chemical modification of NR is to use the reactions of epoxidation, degradation and reduction for preparation of hydroxyl rubber which can be applied as precursors for preparation of block copolymer and polyurethane based natural rubber., Natural rubber (NR), a high molecular weight polymer has mainly found applications in automotive industries. Modification of its cis-1,4 polyisoprenic structure by chemical methods can diversify its applications. One-step chemical modification including epoxidation, maleinization and hydrogenation has been known for improvement of oil and heat resistance which are mostly applied in automotive sector. Researches on multi-step chemical modification will be presented for finding new area of applications. The chemical reactions which are epoxidation followed by degradation and addition of photosensitive molecule can be applied for photocurable coating. While the chemical reactions including epoxidation, followed by ring opening reaction can be resulted in a precursor for further step modification of controlled graft copolymerization using atom transfer radical polymerization. Another interesting pathway for chemical modification of NR is to use the reactions of epoxidation, degradation and reduction for preparation of hydroxyl rubber which can be applied as precursors for preparation of block copolymer and polyurethane based natural rubber.

The weight reduction in rubber products is one of the important subjects. There are several methods of weight reduction in the rubber compound, for example, thin-walled rubber, foam moulding, reduction of heavy filler, and use of light filler. There is a hollow filler as a light filler. The hollow filler has the empty space inside and its density is lighter than other fillers. The hollow filler is considered effective for the weight reduction. However, the hollow filler is sometimes broken under strong stress. Therefore, in using the hollow filler, it is needed to mix weakly or to choose a hollow filler with enough resistance for strong stress. In this study, we investigated the compression behaviours of various hollow fillers by using the micro compression tester. Then, we compounded the rubber with various hollow fillers and discussed the relationship between the state of hollow fillers and the density of rubber compound, The weight reduction in rubber products is one of the important subjects. There are several methods of weight reduction in the rubber compound, for example, thin-walled rubber, foam moulding, reduction of heavy filler, and use of light filler. There is a hollow filler as a light filler. The hollow filler has the empty space inside and its density is lighter than other fillers. The hollow filler is considered effective for the weight reduction. However, the hollow filler is sometimes broken under strong stress. Therefore, in using the hollow filler, it is needed to mix weakly or to choose a hollow filler with enough resistance for strong stress. In this study, we investigated the compression behaviours of various hollow fillers by using the micro compression tester. Then, we compounded the rubber with various hollow fillers and discussed the relationship between the state of hollow fillers and the density of rubber compound

ADC 12, which is suitable for casting and machining, is one of the common aluminum alloys for automobiles. However the corrosion resistance of ADC12 is insufficient in comparison with other aluminum alloys. Therefore excessive corrosion of ADC12 occurred when salt water contact it. In particular, the corrosion occurred at sealing gap between rubber gasket and aluminum alloy and it caused leakage. It is considered that surface roughness of aluminum and water repellent property of sealing gap affect intrusion of salt water into the sealing gap. In this study, the method to prevent the corrosion at the sealing surface was investigated focusing on the surface roughness and water repellent property., ADC 12, which is suitable for casting and machining, is one of the common aluminum alloys for automobiles. However the corrosion resistance of ADC12 is insufficient in comparison with other aluminum alloys. Therefore excessive corrosion of ADC12 occurred when salt water contact it. In particular, the corrosion occurred at sealing gap between rubber gasket and aluminum alloy and it caused leakage. It is considered that surface roughness of aluminum and water repellent property of sealing gap affect intrusion of salt water into the sealing gap. In this study, the method to prevent the corrosion at the sealing surface was investigated focusing on the surface roughness and water repellent property.

Fluorinated natural rubber were prepared by two-step chemical modification which is a new route to prepare fluoropolymers. In the first reaction, hydroxylated natural rubber was successfully synthesized via hydroxylation in the presence of tungsten complex catalyst with hydrogen peroxide as an oxidant. In the second step, esterification of hydroxylated natural rubber using fluorine-containing acyl chloride under mild conditions was conducted, leading to natural rubber bearing fluoro groups. ATR-FTIR and 1H NMR spectroscopies were used to elucidate the structure of fluorinated liquid natural rubber., Fluorinated natural rubber were prepared by two-step chemical modification which is a new route to prepare fluoropolymers. In the first reaction, hydroxylated natural rubber was successfully synthesized via hydroxylation in the presence of tungsten complex catalyst with hydrogen peroxide as an oxidant. In the second step, esterification of hydroxylated natural rubber using fluorine-containing acyl chloride under mild conditions was conducted, leading to natural rubber bearing fluoro groups. ATR-FTIR and 1H NMR spectroscopies were used to elucidate the structure of fluorinated liquid natural rubber.

Brominated natural rubber (BrDPNR) was prepared by bromination of deproteinized natural rubber (DPNR) with N-bromosuccinimide (NBS) in a dichloromethane solution. The BrDPNR was characterized by 1D and 2D-NMR spectroscopy. The bromine atom content of the BrDPNR was dependent on the amount of NBS; that is, higher the amount of NBS, the higher the bromine atom content of the BrDPNR. The glass transition temperature of BrDPNR increased from -68°C to -16°C as amount of bromine atom increased. Cis-trans isomerization of isoprene units during the bromination was found by NMR measurements., Brominated natural rubber (BrDPNR) was prepared by bromination of deproteinized natural rubber (DPNR) with N-bromosuccinimide (NBS) in a dichloromethane solution. The BrDPNR was characterized by 1D and 2D-NMR spectroscopy. The bromine atom content of the BrDPNR was dependent on the amount of NBS; that is, higher the amount of NBS, the higher the bromine atom content of the BrDPNR. The glass transition temperature of BrDPNR increased from -68°C to -16°C as amount of bromine atom increased. Cis-trans isomerization of isoprene units during the bromination was found by NMR measurements.

Rechargeable magnesium (Mg) battery is noteworthy and expecting as one of next-generation candidates for large energy storage devices. In this work, we have prepared a gel polymer electrolyte (GPE) consisting of poly(tetrahydrofuran) (PTHF) network with triethylene glycol dimethyl ether (G3) electrolyte including magnesium bis(trifluoromethanesulfonyl)imide (Mg(TFSI)2) as salt. The ionic conductivity of GPE exhibited the highest conductivity to be 1.4 × 10−4 S cm−1 at 80 °C for the membrane containing 0.3 M G3/Mg(TFSI)2 solution. Cyclic voltammogram clearly showed a reduction peak at -2.5 V and an oxidation peak at +2.5 V for GPE with the 0.5 M solution., Rechargeable magnesium (Mg) battery is noteworthy and expecting as one of next-generation candidates for large energy storage devices. In this work, we have prepared a gel polymer electrolyte (GPE) consisting of poly(tetrahydrofuran) (PTHF) network with triethylene glycol dimethyl ether (G3) electrolyte including magnesium bis(trifluoromethanesulfonyl)imide (Mg(TFSI)2) as salt. The ionic conductivity of GPE exhibited the highest conductivity to be 1.4 × 10−4 S cm−1 at 80 °C for the membrane containing 0.3 M G3/Mg(TFSI)2 solution. Cyclic voltammogram clearly showed a reduction peak at -2.5 V and an oxidation peak at +2.5 V for GPE with the 0.5 M solution.

Silica has been used as a reinforcing agent of natural rubber (NR) tyres. However, the difference of polarity of both silica and NR could lead to poor mechanical performances. Therefore, polarity of NR should be altered. Herein, NR containing epoxide and carbonyl functional groups was prepared by using 2 chemical reactions, epoxidation using in-situ performic acid to prepare epoxidized NR (ENR) and oxidative degradation using periodic acid to obtain carbonyl functionalized degraded NR (CDNR). ENR containing 9, 14% epoxide contents and CDNR prepared by 0.01,0.02 mol%. periodic acid, compared to isoprenic units, were mixed with 30 phr of silica. The mechanical properties of rubbers filled silica were investigated. It was found that 100% modulus, tensile strength, tear strength and hardness of CDNR/silica vulcanizate were higher than ENR/silica and NR/silica vulcanizates while the elongation at break of allrubber vulcanizates are insignificantly changed. It could be postulated that the chemical modification of NR into CDNR could significantly elevate the interaction between NR and silica, the decrement of silica aggregation occurs, as a result., Silica has been used as a reinforcing agent of natural rubber (NR) tyres. However, the difference of polarity of both silica and NR could lead to poor mechanical performances. Therefore, polarity of NR should be altered. Herein, NR containing epoxide and carbonyl functional groups was prepared by using 2 chemical reactions, epoxidation using in-situ performic acid to prepare epoxidized NR (ENR) and oxidative degradation using periodic acid to obtain carbonyl functionalized degraded NR (CDNR). ENR containing 9, 14% epoxide contents and CDNR prepared by 0.01,0.02 mol%. periodic acid, compared to isoprenic units, were mixed with 30 phr of silica. The mechanical properties of rubbers filled silica were investigated. It was found that 100% modulus, tensile strength, tear strength and hardness of CDNR/silica vulcanizate were higher than ENR/silica and NR/silica vulcanizates while the elongation at break of allrubber vulcanizates are insignificantly changed. It could be postulated that the chemical modification of NR into CDNR could significantly elevate the interaction between NR and silica, the decrement of silica aggregation occurs, as a result.

Stress evaluation in polymeric materials is important to improve the lifetime and durability of polymeric materials. One of the methods to evaluate the stress in polymeric materials is to visualize the stress utilizing mechanochromic polymers. In the present study, dynamic covalent thermoplastic elastomers with mechanochromophore were designed and their mechanochromic behavior was investigated. As a mechanochromic unit, we employed diarylbibenzofuranone (DABBF),1–7 which can afford the corresponding arylbenzofuranone radicals with blue color by the cleavage of the central C–C bond in response to mechanical force. The DABBF unit was introduced to linear ABA triblock copolymers and star-shaped diblock copolymers, and their mechanoresponsive properties were investigated., Stress evaluation in polymeric materials is important to improve the lifetime and durability of polymeric materials. One of the methods to evaluate the stress in polymeric materials is to visualize the stress utilizing mechanochromic polymers. In the present study, dynamic covalent thermoplastic elastomers with mechanochromophore were designed and their mechanochromic behavior was investigated. As a mechanochromic unit, we employed diarylbibenzofuranone (DABBF),1–7 which can afford the corresponding arylbenzofuranone radicals with blue color by the cleavage of the central C–C bond in response to mechanical force. The DABBF unit was introduced to linear ABA triblock copolymers and star-shaped diblock copolymers, and their mechanoresponsive properties were investigated.

This paper describes the preparation process of purified NRL and conferred on their physical properties such as particle size, proteins content, and zeta potential analysis that may govern the colloidal properties of purified NRL., This paper describes the preparation process of purified NRL and conferred on their physical properties such as particle size, proteins content, and zeta potential analysis that may govern the colloidal properties of purified NRL.

In order to understand the local structure and strain field around crack tip of natural rubber (NR) quantitatively, mapping experiments by simultaneous measurements of small angle scattering (SAXS) and wide-angle diffraction (WAXD) were performed using micro X-ray beam of 5 microns in diameter. By converting the transmittance data into thickness, strain distribution around the crack tip was revealed. According to the WAXD data, the crystalline zone was found to be highly localized. At the same time, very sharp streaks were observed in the SAXS patterns at the very edge of the crack tip, which indicate formation and possible expose of fibrils., In order to understand the local structure and strain field around crack tip of natural rubber (NR) quantitatively, mapping experiments by simultaneous measurements of small angle scattering (SAXS) and wide-angle diffraction (WAXD) were performed using micro X-ray beam of 5 microns in diameter. By converting the transmittance data into thickness, strain distribution around the crack tip was revealed. According to the WAXD data, the crystalline zone was found to be highly localized. At the same time, very sharp streaks were observed in the SAXS patterns at the very edge of the crack tip, which indicate formation and possible expose of fibrils.

Comprehensive two-dimensional liquid chromatography (LCxLC) methods were applied to the separation of the ozonolysis products from styrene-butadiene rubber (SBR) containing styrene and vinyl units. The sequences composed of styrene and vinyl units in ozonolysis products were quantitatively detected by mass spectrometer (MS). In this ozonolysis-LCxLCMS method, size exclusion chromatography (SEC) column was used for the first dimension, reverse phase (RP) column was for the second dimension (SECxRPLC). Our experimental results revealed that this analysis may clarify the relationship between the molecular structures of SBR and mechanical properties of silica filled SBR composites, Comprehensive two-dimensional liquid chromatography (LCxLC) methods were applied to the separation of the ozonolysis products from styrene-butadiene rubber (SBR) containing styrene and vinyl units. The sequences composed of styrene and vinyl units in ozonolysis products were quantitatively detected by mass spectrometer (MS). In this ozonolysis-LCxLCMS method, size exclusion chromatography (SEC) column was used for the first dimension, reverse phase (RP) column was for the second dimension (SECxRPLC). Our experimental results revealed that this analysis may clarify the relationship between the molecular structures of SBR and mechanical properties of silica filled SBR composites

We succeeded in reproducing the mechanical behaviour, e.g. reinforcement, hysteresis, and stress softening of filled rubber under cyclic deformations using coarse-grained molecular dynamics simulations (CGMD). We measured density distribution at non-load equilibrium state and conformational change of polymer chains during the deformation. It was found that the polymer-filler attractive interactions increase the polymer density around fillers and decrease the polymer density in the other regions. The polymer bonds, which connects polymer particles away from fillers, are extended as the decrease of the polymer density. This change increases the modulus of the polymer phase, and the reinforcement appears. We also found that the irreversible conformational change of the polymer chains bridging fillers cause hysteresis and stress softening, We succeeded in reproducing the mechanical behaviour, e.g. reinforcement, hysteresis, and stress softening of filled rubber under cyclic deformations using coarse-grained molecular dynamics simulations (CGMD). We measured density distribution at non-load equilibrium state and conformational change of polymer chains during the deformation. It was found that the polymer-filler attractive interactions increase the polymer density around fillers and decrease the polymer density in the other regions. The polymer bonds, which connects polymer particles away from fillers, are extended as the decrease of the polymer density. This change increases the modulus of the polymer phase, and the reinforcement appears. We also found that the irreversible conformational change of the polymer chains bridging fillers cause hysteresis and stress softening

Variation of sulfide linkage during vulcanization of isoprene rubber was evaluated by using sulfur K-edge X-ray absorption near edge structure (S-XANES) spectroscopy. The sample was subjected to the solvent extraction. Fraction of polysulfide, disulfide and monosulfide linkages were quantitatively measured by using a liner combination fitting., Variation of sulfide linkage during vulcanization of isoprene rubber was evaluated by using sulfur K-edge X-ray absorption near edge structure (S-XANES) spectroscopy. The sample was subjected to the solvent extraction. Fraction of polysulfide, disulfide and monosulfide linkages were quantitatively measured by using a liner combination fitting.

It is hard to reliably correlate laboratory based rubber abrasion tests with the wear performance of tyres as it is extremely difficult to achieve the same conditions in both cases. A sticky layer is often formed on the rubber surface during lab based abrasion testing but there are only limited amounts of published data on this sticky debris. In this paper, blade abrasion tests were conducted on a range of tyre tread materials which generated sticky debris under specific test conditions. This sticky debris was characterised using various tests such as TGA, GPC and EDX. The chemical content and the effect of the formation of the sticky debris on the friction and abrasion properties are discussed., It is hard to reliably correlate laboratory based rubber abrasion tests with the wear performance of tyres as it is extremely difficult to achieve the same conditions in both cases. A sticky layer is often formed on the rubber surface during lab based abrasion testing but there are only limited amounts of published data on this sticky debris. In this paper, blade abrasion tests were conducted on a range of tyre tread materials which generated sticky debris under specific test conditions. This sticky debris was characterised using various tests such as TGA, GPC and EDX. The chemical content and the effect of the formation of the sticky debris on the friction and abrasion properties are discussed.

The Japan Rubber Manufacturers Association (JRMA) aims to contribute to the healthy development of the national economy and the daily lives of the Japanese people through its efforts to promote the healthy development of Japan's rubber industry. These efforts include conducting surveys and research on production, distribution, consumption and other trends in the rubber industry, as well as surveys and research on a wide range of issues facing the rubber industry, including technology, labor, the environment, safety, and standardization, which the JRMA then uses to draw up and promote the implementation of related action plans. The JRMA consists of 121 members and associate members. Members include corporations that are engaged in the development and manufacture of rubber products. Associate members are corporations or institutions that support the activities of the JRMA. This report presents the current state of the Japanese and global rubber industries and then introduce the key challenges facing Japan’s rubber industry today and efforts addressing those challenges. It also discusses the need for technology innovation for the future., The Japan Rubber Manufacturers Association (JRMA) aims to contribute to the healthy development of the national economy and the daily lives of the Japanese people through its efforts to promote the healthy development of Japan's rubber industry. These efforts include conducting surveys and research on production, distribution, consumption and other trends in the rubber industry, as well as surveys and research on a wide range of issues facing the rubber industry, including technology, labor, the environment, safety, and standardization, which the JRMA then uses to draw up and promote the implementation of related action plans. The JRMA consists of 121 members and associate members. Members include corporations that are engaged in the development and manufacture of rubber products. Associate members are corporations or institutions that support the activities of the JRMA. This report presents the current state of the Japanese and global rubber industries and then introduce the key challenges facing Japan’s rubber industry today and efforts addressing those challenges. It also discusses the need for technology innovation for the future.

The introduction of tyre labelling legislation by the European Union, the United States, Japan and Korea has increased the desire within the tyre industry for the advancement of silica-filled tyre-tread compounds to achieve lower rolling resistance and better wet traction performance. The improvement of vulcanisate mechanical properties using silica-filled rubber compounds remained a challenge for the tyre manufacturers, due to the high hydrophilicity of silica, which leads to silica particle aggregation. The focus in the present study is to understand the influence of surface modification of silica using different types of bifunctional coupling and monofunctional non-coupling silanes, on the modulus and other properties of silica-filled rubber. Silica aggregate microdispersion, evaluated using a TEM network visualisation method, and the Payne effect, determined through dynamic mechanical analysis, were used to understand the effectiveness of the silica dispersion in the rubber matrix. The study showed that silica surface modification has reduced the silica aggregate size by approximately 30% to 40% compared to an untreated silica-filled rubber vulcanisate. The study also showed improvement in the vulcanisate mechanical properties when coupling silanes were used to modify the silica., The introduction of tyre labelling legislation by the European Union, the United States, Japan and Korea has increased the desire within the tyre industry for the advancement of silica-filled tyre-tread compounds to achieve lower rolling resistance and better wet traction performance. The improvement of vulcanisate mechanical properties using silica-filled rubber compounds remained a challenge for the tyre manufacturers, due to the high hydrophilicity of silica, which leads to silica particle aggregation. The focus in the present study is to understand the influence of surface modification of silica using different types of bifunctional coupling and monofunctional non-coupling silanes, on the modulus and other properties of silica-filled rubber. Silica aggregate microdispersion, evaluated using a TEM network visualisation method, and the Payne effect, determined through dynamic mechanical analysis, were used to understand the effectiveness of the silica dispersion in the rubber matrix. The study showed that silica surface modification has reduced the silica aggregate size by approximately 30% to 40% compared to an untreated silica-filled rubber vulcanisate. The study also showed improvement in the vulcanisate mechanical properties when coupling silanes were used to modify the silica.

This study focuses on the investigation of the influence of the environment on the chemical composition and characteristics of peroxide cured arylonitrile-butadiene rubber (NBR), which provide a novel surface modification method to control the functional groups on cured rubber surfaces through changing the contact environment. Surface and interior functional groups of cured NBR using various moulds at different curing temperature are investigated by X-ray photoelectron spectroscopy (XPS). The results confirmed that hydroxyl, carbonyl, and carboxyl functional groups formed on the cured NBR surfaces, which were changed with the different polarity and chemical characteristics environment changing, This study focuses on the investigation of the influence of the environment on the chemical composition and characteristics of peroxide cured arylonitrile-butadiene rubber (NBR), which provide a novel surface modification method to control the functional groups on cured rubber surfaces through changing the contact environment. Surface and interior functional groups of cured NBR using various moulds at different curing temperature are investigated by X-ray photoelectron spectroscopy (XPS). The results confirmed that hydroxyl, carbonyl, and carboxyl functional groups formed on the cured NBR surfaces, which were changed with the different polarity and chemical characteristics environment changing

It is well known that elastomer nanocomposites possess a complicated multi-scaled structure, such as from the repeating unit( ≈1nm ), the segment length( ≈5-10nm ) to the radius of gyration and end-to-end distance( ≈ 50-100nm ) of polymer chains, and the primary particle( ≈20-50nm ), the aggreagte( ≈100-200nm ) to the agglomerate( ≈1046-10 nm ) of the spherical nanoparticles(NPs). It is always difficult to characterize this multi-scaled structure through experimental tools, and molecular dynamics simulation, as a powerful computational simulation approach, can be employed to overcome this challenge. Besides this multi-scaled structure, to establish the structure-property relation is also lacking, particularly about the static and dynamic mechanical properties. Molecular dynamics simulation can be utilized to conveniently vary a large space of structural parameters such as the size, shape and volume fraction of NPs, the physical and chemical interfacial interaction, the conformation, the molecular weight and its distribution of polymer chains, different dispersion state and morphology, and so on. In order to achieve this target, we need to develop a multi-scale simulation technique to combine the molecular dynamics simulation at the molecular level with the finite element analysis at the microscopic level., It is well known that elastomer nanocomposites possess a complicated multi-scaled structure, such as from the repeating unit( ≈1nm ), the segment length( ≈5-10nm ) to the radius of gyration and end-to-end distance( ≈ 50-100nm ) of polymer chains, and the primary particle( ≈20-50nm ), the aggreagte( ≈100-200nm ) to the agglomerate( ≈1046-10 nm ) of the spherical nanoparticles(NPs). It is always difficult to characterize this multi-scaled structure through experimental tools, and molecular dynamics simulation, as a powerful computational simulation approach, can be employed to overcome this challenge. Besides this multi-scaled structure, to establish the structure-property relation is also lacking, particularly about the static and dynamic mechanical properties. Molecular dynamics simulation can be utilized to conveniently vary a large space of structural parameters such as the size, shape and volume fraction of NPs, the physical and chemical interfacial interaction, the conformation, the molecular weight and its distribution of polymer chains, different dispersion state and morphology, and so on. In order to achieve this target, we need to develop a multi-scale simulation technique to combine the molecular dynamics simulation at the molecular level with the finite element analysis at the microscopic level.

Excellent bio-inert properties of polymers are closely associated with aggregation states and dynamics of chains at the water interface. Recently, we have demonstrated that a diblock copolymer of rubbery poly(2-methoxyethyl vinyl ether) (PMOVE) and glassy poly(cyclohexyl vinyl ether) constructed the segregation layer of PMOVE at the water interface in a film state, leading to a successful suppression of platelet adhesion. Although such a soft layer seems to play a key role in blood-compatibility, that is not out of speculation. In this study, we prepared a cross-linked hydrogel of PMOVE in thin films by a copolymerization of MOVE and 2-(vinyloxy)ethyl methacrylate (VEM) and a subsequent photo cross-linking reaction. By changing cross-linking density, the swelling extent and the resultant elasticity of the hydrogel films near the water interface were well-controlled. Combining this information with results of platelet adhesion test, our understanding of blood-compatibility proceeds further., Excellent bio-inert properties of polymers are closely associated with aggregation states and dynamics of chains at the water interface. Recently, we have demonstrated that a diblock copolymer of rubbery poly(2-methoxyethyl vinyl ether) (PMOVE) and glassy poly(cyclohexyl vinyl ether) constructed the segregation layer of PMOVE at the water interface in a film state, leading to a successful suppression of platelet adhesion. Although such a soft layer seems to play a key role in blood-compatibility, that is not out of speculation. In this study, we prepared a cross-linked hydrogel of PMOVE in thin films by a copolymerization of MOVE and 2-(vinyloxy)ethyl methacrylate (VEM) and a subsequent photo cross-linking reaction. By changing cross-linking density, the swelling extent and the resultant elasticity of the hydrogel films near the water interface were well-controlled. Combining this information with results of platelet adhesion test, our understanding of blood-compatibility proceeds further.

The objective of this research is to study the effects of blend composition and peroxide content on morphology, dynamic mechanical and thermal properties of uncrosslinked and crosslinked EVA/NR blends. EVA/NR volume ratio of 70/30, 60/40, 50/50, 40/60 and 30/70 with DCP content of 0, 0.5 and 1 phr were selected. The results show that DCP can reduce NR domain size as shown in SEM micrographs. No shift of Tgs of EVA and NR was observed, indicating the immiscibility. Degree of crystallinity and storage modulus at 30 °C decreased when NR ratio and DCP content increase., The objective of this research is to study the effects of blend composition and peroxide content on morphology, dynamic mechanical and thermal properties of uncrosslinked and crosslinked EVA/NR blends. EVA/NR volume ratio of 70/30, 60/40, 50/50, 40/60 and 30/70 with DCP content of 0, 0.5 and 1 phr were selected. The results show that DCP can reduce NR domain size as shown in SEM micrographs. No shift of Tgs of EVA and NR was observed, indicating the immiscibility. Degree of crystallinity and storage modulus at 30 °C decreased when NR ratio and DCP content increase.

Segmented thiourethane elastomers were synthesized with 1,4-butanedithiol and 1,5-pentanedithiol as a chain extender. Microphase-separated structure and mechanical properties of these thiourethane elastomers were investigated using Fourier-transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), dynamic viscoelastic property measurements, small-angle x-ray scattering and tensile testing. The differences between thiourethane and general urethane elastomers will be discussed., Segmented thiourethane elastomers were synthesized with 1,4-butanedithiol and 1,5-pentanedithiol as a chain extender. Microphase-separated structure and mechanical properties of these thiourethane elastomers were investigated using Fourier-transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), dynamic viscoelastic property measurements, small-angle x-ray scattering and tensile testing. The differences between thiourethane and general urethane elastomers will be discussed.

This study aimed to investigate the use of coconut shell-based carbon to substitute carbon black in certain rubber products for motorcycle tire application. Two possible alternatives were identified namely, low-value activated carbon (LVAC) and coconut shell charcoal (CSC), both of which are derived from coconut shell. Initial characterizations showed the materials have particle size ranging between 36 to 42 m and 20 to 22 m, respectively, and both contain up to 20% of calcium, iron, and potassium as impurities and 15% volatile matter. As-received LVAC and CSC were directly compounded with rubber that resulted to a tensile strength between 4.32 and 3.71 MPa, respectively. Systematic addition of these fillers to rubber therefore required pre-conditioning by way of acid and heat treatment at specific treatment settings wherein impurities have been reduced to 1% and 3.3% for LVAC and CSC, respectively, while volatile matter content reduced to 0.15%. This, further, resulted to rubber compounds having mechanical properties better than those prepared with as-received forms, This study aimed to investigate the use of coconut shell-based carbon to substitute carbon black in certain rubber products for motorcycle tire application. Two possible alternatives were identified namely, low-value activated carbon (LVAC) and coconut shell charcoal (CSC), both of which are derived from coconut shell. Initial characterizations showed the materials have particle size ranging between 36 to 42 m and 20 to 22 m, respectively, and both contain up to 20% of calcium, iron, and potassium as impurities and 15% volatile matter. As-received LVAC and CSC were directly compounded with rubber that resulted to a tensile strength between 4.32 and 3.71 MPa, respectively. Systematic addition of these fillers to rubber therefore required pre-conditioning by way of acid and heat treatment at specific treatment settings wherein impurities have been reduced to 1% and 3.3% for LVAC and CSC, respectively, while volatile matter content reduced to 0.15%. This, further, resulted to rubber compounds having mechanical properties better than those prepared with as-received forms

A good dispersion of nano-fillers in a polymer matrix is important as it influences the filler-to-polymer interaction and consequently the final properties. Graphene has emerged as top reinforcing material of the century. This paper presents an investigation on the rheological, physical and dynamic properties of graphene nano-fillers reinforcement of carbon black- and silica-filled Natural Rubber. The effect of graphene on the filler-to-rubber and filler-to-filler interactions in natural rubber and epoxidized natural rubber is evaluated by bound rubber content and Payne effect study. In the graphene rubber nanocomposite, improvement in the properties can be achieved at low filler loading, A good dispersion of nano-fillers in a polymer matrix is important as it influences the filler-to-polymer interaction and consequently the final properties. Graphene has emerged as top reinforcing material of the century. This paper presents an investigation on the rheological, physical and dynamic properties of graphene nano-fillers reinforcement of carbon black- and silica-filled Natural Rubber. The effect of graphene on the filler-to-rubber and filler-to-filler interactions in natural rubber and epoxidized natural rubber is evaluated by bound rubber content and Payne effect study. In the graphene rubber nanocomposite, improvement in the properties can be achieved at low filler loading

Special grade of nanosilica: i.e. hydrophobic fumed silica, used for latex applications provides excellent efficiency towards reinforcement in latex-based NR thin films. The morphological images show a uniform dispersion of silica particles which are in the range of nanoscale in size. Due to the achievement of well-dispersed aspect of NR/silica nanocomposite, the mechanical properties of the film, in particular tensile strength, can be maintained when its thickness is sufficiently reduced, but show a dramatic drop in elongatability of the reinforced film compared to the film without nanofiller., Special grade of nanosilica: i.e. hydrophobic fumed silica, used for latex applications provides excellent efficiency towards reinforcement in latex-based NR thin films. The morphological images show a uniform dispersion of silica particles which are in the range of nanoscale in size. Due to the achievement of well-dispersed aspect of NR/silica nanocomposite, the mechanical properties of the film, in particular tensile strength, can be maintained when its thickness is sufficiently reduced, but show a dramatic drop in elongatability of the reinforced film compared to the film without nanofiller.

The life time prediction is always at the forefront of materials researchers. The end of the life of seals is defined when a leakage happened. Until a leak happens, materials gradually degrade due to several factors such as mechanical fatigues, oxidation, temperature, media, and pressure. These factors lead irreversible changes in the physical and chemical property of materials. Especially the deformation conditions to which rubber are subjected have a considerable effect and, in many cases, the decisive effect on their service life. Therefore, in practical, it is important to consider thermal oxidation under stress. However, it is difficult to analyze the rubber oxidation even without stress. The available information on the oxidation of materials under stress is very scarce and mostly qualitative in the previous studies.This paper focuses on the oxidative reaction rate and activation energy under deformation., The life time prediction is always at the forefront of materials researchers. The end of the life of seals is defined when a leakage happened. Until a leak happens, materials gradually degrade due to several factors such as mechanical fatigues, oxidation, temperature, media, and pressure. These factors lead irreversible changes in the physical and chemical property of materials. Especially the deformation conditions to which rubber are subjected have a considerable effect and, in many cases, the decisive effect on their service life. Therefore, in practical, it is important to consider thermal oxidation under stress. However, it is difficult to analyze the rubber oxidation even without stress. The available information on the oxidation of materials under stress is very scarce and mostly qualitative in the previous studies.This paper focuses on the oxidative reaction rate and activation energy under deformation.

Natural rubber (NR) shows fluctuation of some properties that can cause undesirable changes in behaviour during its processing. In 1965, Standard Malaysian Rubber (SMR) specification was established to allow natural rubber classification into several quality groups according to impurities content and processing parameters. It determines limits for some analytical data – content of dirt, volatile matters, ash and nitrogen, and for physical quantities that were introduced to evaluate processing parameters – Wallace plasticity, Mooney viscosity and Plasticity retention index (PRI). But praxis shows, that the prediction of processing properties based on these parameters sometimes fails. New testing instruments offer to measure some rubber properties at wider range of deformation rates and/or at dynamic regime. The presented study map if extended testing possibilities can help technologists with above mentioned prediction of natural rubber behaviour., Natural rubber (NR) shows fluctuation of some properties that can cause undesirable changes in behaviour during its processing. In 1965, Standard Malaysian Rubber (SMR) specification was established to allow natural rubber classification into several quality groups according to impurities content and processing parameters. It determines limits for some analytical data – content of dirt, volatile matters, ash and nitrogen, and for physical quantities that were introduced to evaluate processing parameters – Wallace plasticity, Mooney viscosity and Plasticity retention index (PRI). But praxis shows, that the prediction of processing properties based on these parameters sometimes fails. New testing instruments offer to measure some rubber properties at wider range of deformation rates and/or at dynamic regime. The presented study map if extended testing possibilities can help technologists with above mentioned prediction of natural rubber behaviour.

The industrial rubber, commonly used for tyres and engine mounts, shows nonlinear viscoelastic behaviour. For the design of such rubber products, it is important to capture the stress–strain responses under arbitrary loading condition. However, the stress–strain responses show a complicated behaviour, which depends on strain rate, strain history, and strain amplitude. The main purpose of this study is to develop a new constitutive model, which is a micromechanical non-affine network model, for capturing the nonlinear viscoelastic stress–strain response of carbon-black-filled styrene-butadiene rubber vulcanizates (SBR-CB)., The industrial rubber, commonly used for tyres and engine mounts, shows nonlinear viscoelastic behaviour. For the design of such rubber products, it is important to capture the stress–strain responses under arbitrary loading condition. However, the stress–strain responses show a complicated behaviour, which depends on strain rate, strain history, and strain amplitude. The main purpose of this study is to develop a new constitutive model, which is a micromechanical non-affine network model, for capturing the nonlinear viscoelastic stress–strain response of carbon-black-filled styrene-butadiene rubber vulcanizates (SBR-CB).

In order to improve the mechanical properties of silicone rubber, two-phase blends of silicone rubber and polyethylene were prepared by melt-mixing, and then the silicon rubber was crosslinked by using peroxide. The tensile strength and elastic modulus of silicone rubber were found to be increased without the decrease of the strain at break by blending linear low density polyethylene (LLDPE). The improvement of the mechanical properties is attributed to the strong adhesion between silicone rubber matrix and LLDPE domain due to the chemical reaction at the interface of the two-phase by peroxide crosslinking agent. Owing to the difference of the chemical reaction, the improvement of the mechanical properties was larger in the blend of the LLDPE comparing with that of the high density polyethylene (HDPE), though the mechanical properties of the neat LLDPE were lower than those of the neat HDPE., In order to improve the mechanical properties of silicone rubber, two-phase blends of silicone rubber and polyethylene were prepared by melt-mixing, and then the silicon rubber was crosslinked by using peroxide. The tensile strength and elastic modulus of silicone rubber were found to be increased without the decrease of the strain at break by blending linear low density polyethylene (LLDPE). The improvement of the mechanical properties is attributed to the strong adhesion between silicone rubber matrix and LLDPE domain due to the chemical reaction at the interface of the two-phase by peroxide crosslinking agent. Owing to the difference of the chemical reaction, the improvement of the mechanical properties was larger in the blend of the LLDPE comparing with that of the high density polyethylene (HDPE), though the mechanical properties of the neat LLDPE were lower than those of the neat HDPE.

The effects of three silane coupling agents on filler-rubber interactions, crosslink density, and crosslink structure of silica-filled solution styrene-butadiene rubber (SSBR) vulcanizates were studied. Crosslink density was calculated by using the Flory-Rehner equation. Filler-rubber interactions in the vulcanizates were determined using the Kraus equation. Experimental results show that Kraus plots are applicable to silica-filled SSBR vulcanizates. Filler-rubber interactions, crosslink density, and crosslink structure of the silica-filled SSBR compounds were determined according to the silanes, The effects of three silane coupling agents on filler-rubber interactions, crosslink density, and crosslink structure of silica-filled solution styrene-butadiene rubber (SSBR) vulcanizates were studied. Crosslink density was calculated by using the Flory-Rehner equation. Filler-rubber interactions in the vulcanizates were determined using the Kraus equation. Experimental results show that Kraus plots are applicable to silica-filled SSBR vulcanizates. Filler-rubber interactions, crosslink density, and crosslink structure of the silica-filled SSBR compounds were determined according to the silanes

Novel network structure formation by applying an electric field of nanodiamond (ND) in UV cure resin was investigated. When an electric field was applied to ND/UV resin, UV resin took place electro-hydrodynamic (EHD) convection and ND particles flowed in accordance with the convection. Some minutes later, ND particles gathered in the vicinity of the positive surface due to the electrostatic attractive force between the positive surface and surface charge of ND. The sheet with ND network formed in one surface could be obtained by photo-polymerization during applying the electric field. Compared with the sample unapplied an electric field, applied sample showed lower surface resistivity and higher surface thermal conductivity, because ND network acted as the conducting path of electricity and heat, Novel network structure formation by applying an electric field of nanodiamond (ND) in UV cure resin was investigated. When an electric field was applied to ND/UV resin, UV resin took place electro-hydrodynamic (EHD) convection and ND particles flowed in accordance with the convection. Some minutes later, ND particles gathered in the vicinity of the positive surface due to the electrostatic attractive force between the positive surface and surface charge of ND. The sheet with ND network formed in one surface could be obtained by photo-polymerization during applying the electric field. Compared with the sample unapplied an electric field, applied sample showed lower surface resistivity and higher surface thermal conductivity, because ND network acted as the conducting path of electricity and heat

Recently, the reduction of the energy loss in cars has been one of the most important issues in global warming countermeasures. To reduce the loss energy in car driving, it is important to investigate the internal structures formed in tire or rubber-filler systems and to explore the relationship between the physical properties of the systems. Thus, the analyses of the internal structure can contribute to the reduction of the loss of the energy. Since fillers in polymers form hierarchical structure over wide length scale, the exploration of the whole structure was rather difficult. Recently, Ultra-small-angle scattering technique has become available for us to measure the structure in the order of micron scale and the combination of various scattering techniques can cover the wide length scale where fillers in polymers forms hierarchical structure. In previous studies, the hierarchical structures formed by carbon black (CB) filler in polymers have been investigated by using a combined ultra-small-angle and small-angle scattering method of neutrons and X-rays and explored the network structures of CB having mass-fractal features, the size and shape of aggregation, and surface-fractal features of CB particles. Moreover, we have recently characterized the adsorption layers as well as the aggregation of silica particles by using contrast variation small-angle neutron scattering technique. In this study, we focus on a rubber-CB particles system and characterize the adsorption layers on CB particles by using contrast variation small-angle neutron scattering (SANS) technique and characterize the adsorption layers as well as the aggregation of CB particles, network structures in matrix, and so on., Recently, the reduction of the energy loss in cars has been one of the most important issues in global warming countermeasures. To reduce the loss energy in car driving, it is important to investigate the internal structures formed in tire or rubber-filler systems and to explore the relationship between the physical properties of the systems. Thus, the analyses of the internal structure can contribute to the reduction of the loss of the energy. Since fillers in polymers form hierarchical structure over wide length scale, the exploration of the whole structure was rather difficult. Recently, Ultra-small-angle scattering technique has become available for us to measure the structure in the order of micron scale and the combination of various scattering techniques can cover the wide length scale where fillers in polymers forms hierarchical structure. In previous studies, the hierarchical structures formed by carbon black (CB) filler in polymers have been investigated by using a combined ultra-small-angle and small-angle scattering method of neutrons and X-rays and explored the network structures of CB having mass-fractal features, the size and shape of aggregation, and surface-fractal features of CB particles. Moreover, we have recently characterized the adsorption layers as well as the aggregation of silica particles by using contrast variation small-angle neutron scattering technique. In this study, we focus on a rubber-CB particles system and characterize the adsorption layers on CB particles by using contrast variation small-angle neutron scattering (SANS) technique and characterize the adsorption layers as well as the aggregation of CB particles, network structures in matrix, and so on.

This paper investigates the efficient promotion of hydrolysis of PUAs in high-temperature water under high pressure of CO2 which are nonhazardous in nature. Another important advantage of this process is that it does not require neutralization and further purification of the obtained corresponding DA from PUA. The advantageous feature is not attained by various acids. In summary, although further investigation is needed to precisely settle the mechanism, the paper provides a green and general method for the hydrolysis of urea linkage via carbonic acid from the reaction of CO2 with H2O., This paper investigates the efficient promotion of hydrolysis of PUAs in high-temperature water under high pressure of CO2 which are nonhazardous in nature. Another important advantage of this process is that it does not require neutralization and further purification of the obtained corresponding DA from PUA. The advantageous feature is not attained by various acids. In summary, although further investigation is needed to precisely settle the mechanism, the paper provides a green and general method for the hydrolysis of urea linkage via carbonic acid from the reaction of CO2 with H2O.

Realization of low-carbon society has been advocated to settle urgent environmental issues such as global warming and energy shortage. Application of hydrogen as an energy carrier is regarded as a very promising candidate, and has already been utilized in fuel-cell vehicles and stationary fuel-cells. However, there are still some problems in the safe and efficient use of hydrogen in practice. Aiming to the improvement of property of rubber materials used in the devices for storage, delivery and filling of hydrogen, we have pursue the causes of deterioration of sealing property of rubber materials exposed to high-pressure hydrogen. We have reported that hydrogen penetrated into the rubber materials causes blister fracture, and the volume expansion by the penetrated hydrogen causes overflow fracture1). Also, the deterioration of elastic modulus by Mullins effect due to the repetition of hydrogen pressurization and decompression have been reported. These damages of the rubber materials are influenced by the content of dissolved hydrogen and strength of the materials. Addition of fillers are necessary for the reinforcement. To verify the effects of fillers, we examined the difference of hydrogen property in various acrylonitrile butadiene rubber (NBR) with different types of carbon black (CB) by evaluating the hydrogen dissolving behaviour derived from hydrogen elimination behaviour., Realization of low-carbon society has been advocated to settle urgent environmental issues such as global warming and energy shortage. Application of hydrogen as an energy carrier is regarded as a very promising candidate, and has already been utilized in fuel-cell vehicles and stationary fuel-cells. However, there are still some problems in the safe and efficient use of hydrogen in practice. Aiming to the improvement of property of rubber materials used in the devices for storage, delivery and filling of hydrogen, we have pursue the causes of deterioration of sealing property of rubber materials exposed to high-pressure hydrogen. We have reported that hydrogen penetrated into the rubber materials causes blister fracture, and the volume expansion by the penetrated hydrogen causes overflow fracture1). Also, the deterioration of elastic modulus by Mullins effect due to the repetition of hydrogen pressurization and decompression have been reported. These damages of the rubber materials are influenced by the content of dissolved hydrogen and strength of the materials. Addition of fillers are necessary for the reinforcement. To verify the effects of fillers, we examined the difference of hydrogen property in various acrylonitrile butadiene rubber (NBR) with different types of carbon black (CB) by evaluating the hydrogen dissolving behaviour derived from hydrogen elimination behaviour.

Die swell and other viscoelastic characteristics imparted to a rubber compound by different elastomers and reinforcing fillers are very relevant to compound performance in extrusion, calendering, molding, and other factory operations. In this study, a capillary rheometer was used to measure the die swell and other rheological behavior at different shear rates. Model rubber compounds were prepared and tested. Processability characteristics were also measured for these mixed stocks using the RPA with EDR. Comparisons were made of the performance behavior for these compounds. Statistical analyses were performed on running die swell and relaxed die swell vs. tan delta and G’ under a wide range of applied frequencies and strain amplitudes with the Rubber Process Analyzer (RPA). Observations were made and discussed for the tan delta inversion crossovers which may prove useful in quantifying state of mix and degree of in-situ silanization during the mixing process., Die swell and other viscoelastic characteristics imparted to a rubber compound by different elastomers and reinforcing fillers are very relevant to compound performance in extrusion, calendering, molding, and other factory operations. In this study, a capillary rheometer was used to measure the die swell and other rheological behavior at different shear rates. Model rubber compounds were prepared and tested. Processability characteristics were also measured for these mixed stocks using the RPA with EDR. Comparisons were made of the performance behavior for these compounds. Statistical analyses were performed on running die swell and relaxed die swell vs. tan delta and G’ under a wide range of applied frequencies and strain amplitudes with the Rubber Process Analyzer (RPA). Observations were made and discussed for the tan delta inversion crossovers which may prove useful in quantifying state of mix and degree of in-situ silanization during the mixing process.

Natural rubber is a highly suitable for dynamic applications. Its mechanical properties are network dependent. Key parameters include the density of vulcanization and the length of sulfur bonds. We used low field NMR to characterize the cross link density and the number of monomer between two sulfur bonds. Nevertheless, today there is no analytical method able to measure or determine correctly the sulfur bond length. It is possible to tune the distribution of the sulfur bond length by varying the sulfur/accelerator ratio. In order to focus only on sulfur bond length contribution, we propose here to compare three polyisoprene blends with different sulfur accelerator ratio, corresponding to CV, EV and SEV vulcanization system, with the same cross link density. Network topology and mechanical properties of these samples were then studied and several approaches using spectroscopic and chemical analysis were performed to investigate the different sulfur bonds length., Natural rubber is a highly suitable for dynamic applications. Its mechanical properties are network dependent. Key parameters include the density of vulcanization and the length of sulfur bonds. We used low field NMR to characterize the cross link density and the number of monomer between two sulfur bonds. Nevertheless, today there is no analytical method able to measure or determine correctly the sulfur bond length. It is possible to tune the distribution of the sulfur bond length by varying the sulfur/accelerator ratio. In order to focus only on sulfur bond length contribution, we propose here to compare three polyisoprene blends with different sulfur accelerator ratio, corresponding to CV, EV and SEV vulcanization system, with the same cross link density. Network topology and mechanical properties of these samples were then studied and several approaches using spectroscopic and chemical analysis were performed to investigate the different sulfur bonds length.

Thermoplastic vulcanizates (TPVs) are a particular group of thermoplastic elastomers produced by dynamic vulcanization, which consists of the selective crosslinking of the elastomer and its fine dispersion throughout the thermoplastic phase under intensive mixing. TPV combines the excellent resilience of ordinary vulcanized rubbers and the high processability of thermoplastics, and the morphology of TPV has a significant influence on its mechanical properties and processability.[, Thermoplastic vulcanizates (TPVs) are a particular group of thermoplastic elastomers produced by dynamic vulcanization, which consists of the selective crosslinking of the elastomer and its fine dispersion throughout the thermoplastic phase under intensive mixing. TPV combines the excellent resilience of ordinary vulcanized rubbers and the high processability of thermoplastics, and the morphology of TPV has a significant influence on its mechanical properties and processability.[

This paper discusses rubber in future from a view point of automobile developing. Rubber has supported the evolution of automobiles by its various functions so far. This material, however, has disadvantages an aspect of difficulty in comparison with metal and resin which are used a lot. It was the lack of standard materials and was not elucidated in most case. One of the reasons of that is that vehicle parts design was complicated. On the contrary, rubber has unknown possibilities not to be restricted by a standard. A lot of new techniques are necessary, and they need to be adapted to fit the preferences and tastes of the people for the prosperity of automobiles. Therefore, the future automobile depends on new functions of rubber and the elucidation of the mysteries of rubber. In this paper, some rubber-rerated knowledge provided through car development is also introduced. These show partly rubber’s marvels, future possibilities and characteristics in actual situation., This paper discusses rubber in future from a view point of automobile developing. Rubber has supported the evolution of automobiles by its various functions so far. This material, however, has disadvantages an aspect of difficulty in comparison with metal and resin which are used a lot. It was the lack of standard materials and was not elucidated in most case. One of the reasons of that is that vehicle parts design was complicated. On the contrary, rubber has unknown possibilities not to be restricted by a standard. A lot of new techniques are necessary, and they need to be adapted to fit the preferences and tastes of the people for the prosperity of automobiles. Therefore, the future automobile depends on new functions of rubber and the elucidation of the mysteries of rubber. In this paper, some rubber-rerated knowledge provided through car development is also introduced. These show partly rubber’s marvels, future possibilities and characteristics in actual situation.

In this study, a facile method for the fabrication of NBR/bentonite composites was utilized and various silane coupling agents were applied during the fabrication as compatibilizers. Compared to conventional methods, this protocol is economical and environment-friendly with no organic solvent involved. Effects of different coupling agents on chemical and physical structures of the composites were characterized and evaluated with Fourier transform spectroscopy (FTIR) and X-ray diffraction (XRD). Field emission-scanning electron microscopy (FE-SEM) was used to investigate the morphology in tensile test and abrasion test. Incorporated with (3-Mercaptopropyl)trimethoxysilane (MPTMS), the composites showed better performances in mechanical strength and shore A hardness while in thermal gravimetric analysis (TGA). Most of the silanes exhibited positive effects to the thermal stability of the composites. With various silane coupling agents, the composites exhibited different rheological behaviours during vulcanization, which were characterized with rubber processing analyzer (RPA). Friction coefficient and wear loss rate of the composites prepared with certain silanes were also evaluated by friction test and abrasion test. Different lubricants, including graphite and molybdenum disulphide, were also incorporated into the composites during compounding. Their synergistic effects with bentonite and silane coupling agents on the mechanical and thermal properties of the composites were further investigated., In this study, a facile method for the fabrication of NBR/bentonite composites was utilized and various silane coupling agents were applied during the fabrication as compatibilizers. Compared to conventional methods, this protocol is economical and environment-friendly with no organic solvent involved. Effects of different coupling agents on chemical and physical structures of the composites were characterized and evaluated with Fourier transform spectroscopy (FTIR) and X-ray diffraction (XRD). Field emission-scanning electron microscopy (FE-SEM) was used to investigate the morphology in tensile test and abrasion test. Incorporated with (3-Mercaptopropyl)trimethoxysilane (MPTMS), the composites showed better performances in mechanical strength and shore A hardness while in thermal gravimetric analysis (TGA). Most of the silanes exhibited positive effects to the thermal stability of the composites. With various silane coupling agents, the composites exhibited different rheological behaviours during vulcanization, which were characterized with rubber processing analyzer (RPA). Friction coefficient and wear loss rate of the composites prepared with certain silanes were also evaluated by friction test and abrasion test. Different lubricants, including graphite and molybdenum disulphide, were also incorporated into the composites during compounding. Their synergistic effects with bentonite and silane coupling agents on the mechanical and thermal properties of the composites were further investigated.

We investigated the morphology and stretching behavior of polyurethane (PU), consisting of poly(tetramethylene ether) glycol. Spherulites were developed by isothermal annealing after melting at high temperature and the spherulite morphology was found to be changed by melting at different temperatures; e.g., compact spherulites and coarse-and-open ones were obtained by melting at 200⁰C and 220-230⁰C, respectively. The in-situ observation of the spherulite growth revealed that the neighboring spherulites were interpenetrated after the collision of the spherulites. The interpenetration of the spherulites might be attributed to the existence of the tie molecules of the neighboring spherulites and the crystallization of the locally arranged fringed-micellar crystals. The PU spherulites thus obtained exhibited good strain recovery, though large spherulites existed. The spherulites were deformed to the ellipsoidal one, and then fibrillar structure was formed at the interface of the neighboring spherulites and was elongated into finer one during the stretching. Such fibrillar formation is induced by tie molecules in the interpenetrated region of the neighboring spherulites. The deformed spherulites were changed to spherical ones and the fibrillar structure disappeared during the recovery process., We investigated the morphology and stretching behavior of polyurethane (PU), consisting of poly(tetramethylene ether) glycol. Spherulites were developed by isothermal annealing after melting at high temperature and the spherulite morphology was found to be changed by melting at different temperatures; e.g., compact spherulites and coarse-and-open ones were obtained by melting at 200⁰C and 220-230⁰C, respectively. The in-situ observation of the spherulite growth revealed that the neighboring spherulites were interpenetrated after the collision of the spherulites. The interpenetration of the spherulites might be attributed to the existence of the tie molecules of the neighboring spherulites and the crystallization of the locally arranged fringed-micellar crystals. The PU spherulites thus obtained exhibited good strain recovery, though large spherulites existed. The spherulites were deformed to the ellipsoidal one, and then fibrillar structure was formed at the interface of the neighboring spherulites and was elongated into finer one during the stretching. Such fibrillar formation is induced by tie molecules in the interpenetrated region of the neighboring spherulites. The deformed spherulites were changed to spherical ones and the fibrillar structure disappeared during the recovery process.

In this paper the history of J-NMC is briefly introduced before the two standards, “Determination of biobased content for rubber products” and “International standardization of seismic-protection Elastomeric Isolators” proposed from Japan, are presented., In this paper the history of J-NMC is briefly introduced before the two standards, “Determination of biobased content for rubber products” and “International standardization of seismic-protection Elastomeric Isolators” proposed from Japan, are presented.

It was found that two different types of void growth occur simultaneously. In the polymer matrix, binodal-like nucleation and growth process was observed. On the other hand, around the polymer-filler interface, spinodal-like patter formation took place., It was found that two different types of void growth occur simultaneously. In the polymer matrix, binodal-like nucleation and growth process was observed. On the other hand, around the polymer-filler interface, spinodal-like patter formation took place.

In the oil and gas field, seals may be exposed to rapid gas decompression (RGD). This phenomenon causes damages in elastomer seals (blisters, fractures...) leading to leaks in the system. Many studies have already been performed on this subject enabling to set up standard specifications to qualify seals in specific environments (Pressure, Temperature...). This paper emphasizes the complementarity of using different test methods to classify and study the behaviour of elastomeric seals. In the present study, both NACE-TM-192-098 and TOTAL-GS-EP-PVV-142-rev.-5 specifications have been applied on 8 different materials compounded with or without nanofillers. A classification based on observed damages after both test procedures application has been defined. Even if the TOTAL specification appears to be more severe, a correlation between these two classifications is observed. Thanks to this method, a first selection of materials with a lighter experimental procedure is possible. It can be used to optimize the number of samples tested with the TOTAL specification, which involves more representative conditions of the operating conditions. This paper also highlights the positive impact of nanofillers addition in the elastomer matrices, on the RGD resistance., In the oil and gas field, seals may be exposed to rapid gas decompression (RGD). This phenomenon causes damages in elastomer seals (blisters, fractures...) leading to leaks in the system. Many studies have already been performed on this subject enabling to set up standard specifications to qualify seals in specific environments (Pressure, Temperature...). This paper emphasizes the complementarity of using different test methods to classify and study the behaviour of elastomeric seals. In the present study, both NACE-TM-192-098 and TOTAL-GS-EP-PVV-142-rev.-5 specifications have been applied on 8 different materials compounded with or without nanofillers. A classification based on observed damages after both test procedures application has been defined. Even if the TOTAL specification appears to be more severe, a correlation between these two classifications is observed. Thanks to this method, a first selection of materials with a lighter experimental procedure is possible. It can be used to optimize the number of samples tested with the TOTAL specification, which involves more representative conditions of the operating conditions. This paper also highlights the positive impact of nanofillers addition in the elastomer matrices, on the RGD resistance.

Shear viscosity is the most important material property for the determination of the required filling pressure and the flow pattern in injection molding simulation. Its accurate measurement is therefore crucial for reliable simulation results. This is particularly complex for highly filled rubber compounds, where both the polymer, the fillers as well as interactions of both contribute to the resulting viscosity. Thereby, the contribution of the fillers also depends on the material processing prehistory. Conventional measurement concepts for determining viscosity like high pressure capillary rheometer, rubber process analyzer and others suffer from the draw-back that the material prehistory for the measurement differs significantly from that occurring during the injection process in injection molding. In this work, a measurement concept is presented that overcomes this problem. It features an injection mold containing a rheological measurement slit mountable on a conventional, horizontal rubber injection molding machine. The fitted pressure sensors in the slit enable the measurement of shear viscosity taking into account the material prehistory of the injection molding process., Shear viscosity is the most important material property for the determination of the required filling pressure and the flow pattern in injection molding simulation. Its accurate measurement is therefore crucial for reliable simulation results. This is particularly complex for highly filled rubber compounds, where both the polymer, the fillers as well as interactions of both contribute to the resulting viscosity. Thereby, the contribution of the fillers also depends on the material processing prehistory. Conventional measurement concepts for determining viscosity like high pressure capillary rheometer, rubber process analyzer and others suffer from the draw-back that the material prehistory for the measurement differs significantly from that occurring during the injection process in injection molding. In this work, a measurement concept is presented that overcomes this problem. It features an injection mold containing a rheological measurement slit mountable on a conventional, horizontal rubber injection molding machine. The fitted pressure sensors in the slit enable the measurement of shear viscosity taking into account the material prehistory of the injection molding process.