Pub Date : 2009-07-13DOI: 10.1177/0095244309100531
A. Nicolini, Tatiana Louise Avila de Campos Rocha, Marly Maldaner Jacobi
The comparative study between two curing agents, conventional peroxide (Peroximon) and bismaleimide/dicumyl peroxide combination (BMI/DCP), and the influence of composition in TPE-Vs based on polypropylene (PP) and ethylene—propylene—diene terpolymer (EPDM) were investigated. The materials were characterized by mechanical, hardness, swelling and morphological properties. The TPE-Vs obtained using Peroximon presented lower tensile strength, remarkable lower deformation and swelling degrees than those cured with BMI/DCP. Among all the investigated PP/EPDM compositions, the content of thermoplastic increases the tensile at break. The experimental swelling values are in agreement with the theoretical for the TPE-Vs obtained using BMI/DCP and for the obtained using Peroximon all compositions showed experimental swelling degree higher than the theoretical ones. The hardness is determined by the amount of PP. We also observed in the morphology studies that the rubber domains are smaller and better defined when the BMI/DCP is used.
{"title":"Dynamically Vulcanized PP/EPDM Blends: Effect of Composition and Curing Agents","authors":"A. Nicolini, Tatiana Louise Avila de Campos Rocha, Marly Maldaner Jacobi","doi":"10.1177/0095244309100531","DOIUrl":"https://doi.org/10.1177/0095244309100531","url":null,"abstract":"The comparative study between two curing agents, conventional peroxide (Peroximon) and bismaleimide/dicumyl peroxide combination (BMI/DCP), and the influence of composition in TPE-Vs based on polypropylene (PP) and ethylene—propylene—diene terpolymer (EPDM) were investigated. The materials were characterized by mechanical, hardness, swelling and morphological properties. The TPE-Vs obtained using Peroximon presented lower tensile strength, remarkable lower deformation and swelling degrees than those cured with BMI/DCP. Among all the investigated PP/EPDM compositions, the content of thermoplastic increases the tensile at break. The experimental swelling values are in agreement with the theoretical for the TPE-Vs obtained using BMI/DCP and for the obtained using Peroximon all compositions showed experimental swelling degree higher than the theoretical ones. The hardness is determined by the amount of PP. We also observed in the morphology studies that the rubber domains are smaller and better defined when the BMI/DCP is used.","PeriodicalId":15644,"journal":{"name":"Journal of Elastomers and Plastics","volume":"16 1","pages":"433 - 446"},"PeriodicalIF":1.7,"publicationDate":"2009-07-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84615225","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2009-07-01DOI: 10.1177/0095244309099413
L. Gonella, A. J. Zattera, M. Zeni, R.V.B. Oliveira, L. B. Canto
A new method to reclaim thermoset polyurethane (PU) foam by thermo-mechanical degradation using a batch Drais mixer was investigated, and the performance of reclaimed PU in blends with polyamide-12 (PA-12) or thermoplastic polyurethane (TPU) was studied. The reclamation method used disrupts the crosslinked structure of PU, decreasing its degree of crosslinking, which was confirmed through the determination of gel content, and by DSC, TGA and FTIR analyses. Under severe reclaiming conditions, the reclaimed PU was found to retain about half of its initial gel content. The blends of original PU and reclaimed PU (PU-r) with PA-12 and with TPU were prepared using a twin-screw extruder and were characterized with respect to their mechanical properties. For the PA-12/PU 75/25 blend, the addition of PU was observed to toughen the PA-12 matrix whereas for TPU/PU blends, the rubber-like behavior of TPU was not significantly affected by the presence of PU. The remarkable mechanical behavior of the blends attests to the high compatibility of PU-r with both PA-12 and TPU. This may be due to the physical interactions between the blend components, leading to high interfacial adhesion. The reclamation of PU-r before its melt processing with PA-12 or TPU was found to improve the processability during the injection molding of the PA-12/PU-r and TPU/PU-r blends.
{"title":"New Reclaiming Process of Thermoset Polyurethane Foam and Blending with Polyamide-12 and Thermoplastic Polyurethane","authors":"L. Gonella, A. J. Zattera, M. Zeni, R.V.B. Oliveira, L. B. Canto","doi":"10.1177/0095244309099413","DOIUrl":"https://doi.org/10.1177/0095244309099413","url":null,"abstract":"A new method to reclaim thermoset polyurethane (PU) foam by thermo-mechanical degradation using a batch Drais mixer was investigated, and the performance of reclaimed PU in blends with polyamide-12 (PA-12) or thermoplastic polyurethane (TPU) was studied. The reclamation method used disrupts the crosslinked structure of PU, decreasing its degree of crosslinking, which was confirmed through the determination of gel content, and by DSC, TGA and FTIR analyses. Under severe reclaiming conditions, the reclaimed PU was found to retain about half of its initial gel content. The blends of original PU and reclaimed PU (PU-r) with PA-12 and with TPU were prepared using a twin-screw extruder and were characterized with respect to their mechanical properties. For the PA-12/PU 75/25 blend, the addition of PU was observed to toughen the PA-12 matrix whereas for TPU/PU blends, the rubber-like behavior of TPU was not significantly affected by the presence of PU. The remarkable mechanical behavior of the blends attests to the high compatibility of PU-r with both PA-12 and TPU. This may be due to the physical interactions between the blend components, leading to high interfacial adhesion. The reclamation of PU-r before its melt processing with PA-12 or TPU was found to improve the processability during the injection molding of the PA-12/PU-r and TPU/PU-r blends.","PeriodicalId":15644,"journal":{"name":"Journal of Elastomers and Plastics","volume":"72 1","pages":"303 - 322"},"PeriodicalIF":1.7,"publicationDate":"2009-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84321264","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2009-07-01DOI: 10.1177/0095244309104461
Hadi Mohammadigoushki, H. Nazockdast, N. Mostofi
The morphology development and melt linear viscoelastic properties of PA6/PP/PS (70/15/15) ternary blends were studied. An attempt was also made to predict the morphology development of these blends using the dynamic interfacial tension of the blend components evaluated from the Palierne's viscoelastic model in conjunction with spreading coefficient approach. The blend samples were prepared by melt blending in an internal mixer at temperature of 260°C and rotor speed of 60 rpm. The ternary blend samples exhibited a pronounced low-frequency nonterminal storage modulus whose values were much greater than those predicted for elastic response of the binary blend samples. This was attributed to strong elastic resistance of a core-shell composite droplet formed in the ternary blend samples that was evidenced by the SEM micrographs of these samples. The results predicted based on spreading coefficient concept also suggested a core-shell type morphology in which PP core was encapsulated by PS shell as a composite minor phase dispersed in PA6 matrix. It was demonstrated that there is a close relationship between melt viscoelastic properties and morphology of ternary blends.
{"title":"Morphology Development and Melt Linear Viscoelastic Properties of (PA6/PP/PS) Ternary Blend Systems","authors":"Hadi Mohammadigoushki, H. Nazockdast, N. Mostofi","doi":"10.1177/0095244309104461","DOIUrl":"https://doi.org/10.1177/0095244309104461","url":null,"abstract":"The morphology development and melt linear viscoelastic properties of PA6/PP/PS (70/15/15) ternary blends were studied. An attempt was also made to predict the morphology development of these blends using the dynamic interfacial tension of the blend components evaluated from the Palierne's viscoelastic model in conjunction with spreading coefficient approach. The blend samples were prepared by melt blending in an internal mixer at temperature of 260°C and rotor speed of 60 rpm. The ternary blend samples exhibited a pronounced low-frequency nonterminal storage modulus whose values were much greater than those predicted for elastic response of the binary blend samples. This was attributed to strong elastic resistance of a core-shell composite droplet formed in the ternary blend samples that was evidenced by the SEM micrographs of these samples. The results predicted based on spreading coefficient concept also suggested a core-shell type morphology in which PP core was encapsulated by PS shell as a composite minor phase dispersed in PA6 matrix. It was demonstrated that there is a close relationship between melt viscoelastic properties and morphology of ternary blends.","PeriodicalId":15644,"journal":{"name":"Journal of Elastomers and Plastics","volume":"28 7-8","pages":"339 - 351"},"PeriodicalIF":1.7,"publicationDate":"2009-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1177/0095244309104461","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72455101","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2009-07-01DOI: 10.1177/0095244309103663
G. H. Yew, W. Chow, Z. M. Mohd Ishak, A.M. Mohd Yusof
Poly(lactic acid) (PLA) composites consisting of PLA, rice starch (RS), and epoxidized natural rubber (ENR50) are compounded using a twinscrew extruder followed by compression molding. Two types of thermoplastic starch are prepared by mixing RS with glycerol and water. Natural weathering tests are performed on the PLA/RS composites in Penang, Malaysia for 2 months. The average mean temperature and mean relative humidity are 29°C and 70%, respectively. Tensile tests are performed to characterize the mechanical properties of the weathered PLA/RS composites. Morphological studies are performed by using scanning electron microscopy (SEM). The tensile properties of weathered PLA/RS composites decreased slightly, on the other hand, the tensile properties of weathered PLA/SG and PLA/SGW composites decreased drastically. The retention-ability of the PLA composites are relatively low, which may be attributed to the photo-degradation of PLA, chain scission of PLA, oxidation degradation on ENR, moisture absorption of RS, and leaching of RS particles. In addition, discoloration, surface roughness, surface cracking, and embrittlement are observed for all PLA/RS composites. The extent of degradation is increased by the addition of ENR, owing to the fact that ENR is susceptible to oxygen attack, and consequently facilitates degradation. The morphological properties of the weathered PLA/RS composites are transformed to a more brittle behavior, indicating that severe degradation has occurred on the PLA/RS composites.
{"title":"Natural Weathering of Poly (Lactic Acid): Effects of Rice Starch and Epoxidized Natural Rubber","authors":"G. H. Yew, W. Chow, Z. M. Mohd Ishak, A.M. Mohd Yusof","doi":"10.1177/0095244309103663","DOIUrl":"https://doi.org/10.1177/0095244309103663","url":null,"abstract":"Poly(lactic acid) (PLA) composites consisting of PLA, rice starch (RS), and epoxidized natural rubber (ENR50) are compounded using a twinscrew extruder followed by compression molding. Two types of thermoplastic starch are prepared by mixing RS with glycerol and water. Natural weathering tests are performed on the PLA/RS composites in Penang, Malaysia for 2 months. The average mean temperature and mean relative humidity are 29°C and 70%, respectively. Tensile tests are performed to characterize the mechanical properties of the weathered PLA/RS composites. Morphological studies are performed by using scanning electron microscopy (SEM). The tensile properties of weathered PLA/RS composites decreased slightly, on the other hand, the tensile properties of weathered PLA/SG and PLA/SGW composites decreased drastically. The retention-ability of the PLA composites are relatively low, which may be attributed to the photo-degradation of PLA, chain scission of PLA, oxidation degradation on ENR, moisture absorption of RS, and leaching of RS particles. In addition, discoloration, surface roughness, surface cracking, and embrittlement are observed for all PLA/RS composites. The extent of degradation is increased by the addition of ENR, owing to the fact that ENR is susceptible to oxygen attack, and consequently facilitates degradation. The morphological properties of the weathered PLA/RS composites are transformed to a more brittle behavior, indicating that severe degradation has occurred on the PLA/RS composites.","PeriodicalId":15644,"journal":{"name":"Journal of Elastomers and Plastics","volume":"49 1","pages":"369 - 382"},"PeriodicalIF":1.7,"publicationDate":"2009-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84155566","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2009-06-26DOI: 10.1177/0095244309103662
Dong Shin Jeong, Chang Kook Hong, Gyun Taek Lim, G. Seo, Chang Seok Ryu
A networked silica (NS) prepared by interconnecting silica particles with polymeric methylene diphenyl diisocyanate (MDI) was developed for use as a highly effective reinforcing material for rubber compounds without the need to add silane coupling agents. MDI incorporated onto the silica surface formed networks among neighboring silica particles with urethane linkages and produced NS at low cost. The TEM photographs illustrated the improved dispersion and formation of openings among the silica particles, which could allow easy intrusion of rubber molecules. The NS showed a high reinforcing performance for styrene—butadiene rubber (SBR) compounds, suggesting the possibility of replacing the silica reinforcing systems with coupling agents. Due to the absence of any silane-containing coupling agents, the NS does not suffer the disadvantages associated with coupling agents. Since the NS reinforces rubber compounds by the physical entanglement between rubber molecules and the MDI chains, high loading of the NS is more effective in enhancing the mechanical properties of rubber compounds.
{"title":"Networked Silica with Exceptional Reinforcing Performance for SBR Compounds: Interconnected by Methylene Diphenyl Diisocyanate","authors":"Dong Shin Jeong, Chang Kook Hong, Gyun Taek Lim, G. Seo, Chang Seok Ryu","doi":"10.1177/0095244309103662","DOIUrl":"https://doi.org/10.1177/0095244309103662","url":null,"abstract":"A networked silica (NS) prepared by interconnecting silica particles with polymeric methylene diphenyl diisocyanate (MDI) was developed for use as a highly effective reinforcing material for rubber compounds without the need to add silane coupling agents. MDI incorporated onto the silica surface formed networks among neighboring silica particles with urethane linkages and produced NS at low cost. The TEM photographs illustrated the improved dispersion and formation of openings among the silica particles, which could allow easy intrusion of rubber molecules. The NS showed a high reinforcing performance for styrene—butadiene rubber (SBR) compounds, suggesting the possibility of replacing the silica reinforcing systems with coupling agents. Due to the absence of any silane-containing coupling agents, the NS does not suffer the disadvantages associated with coupling agents. Since the NS reinforces rubber compounds by the physical entanglement between rubber molecules and the MDI chains, high loading of the NS is more effective in enhancing the mechanical properties of rubber compounds.","PeriodicalId":15644,"journal":{"name":"Journal of Elastomers and Plastics","volume":"8 1","pages":"353 - 368"},"PeriodicalIF":1.7,"publicationDate":"2009-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82087129","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2009-06-26DOI: 10.1177/0095244309095016
Marcos F. M. Pacheco, O. Bianchi, R. Fiorio, A. J. Zattera, M. Zeni, M. Giovanela, J. S. Crespo
In this study, three different microcellular polyurethane elastomers (MPUE) based on 4,4'-diphenylmethane diisocyanate with different rigid segment contents are prepared (Formulations 1, 2, and 3 with 32, 35, and 42% of rigid segment content, respectively). The MPUE are obtained through a two-step method using a prepolymer system. The samples are analyzed to determine their thermal, morphological, and chemical properties. The thermogravimetric analysis indicates the presence of two degradation stages, referring to the rigid and flexible phases, respectively. The differential scanning calorimetry tests indicate that for the MPUE there was an increase in the glass transition temperature of the flexible phase with an increase in the percent of the rigid phase. An increase in the quantity of the rigid phase present in the MPUE results in greater values for the crosslink density, which in turn results in an increase in the rigidity of the material. The scanning electron microscopy micrographs indicated a large number of closed cells and that a higher rigid segment content give a better cell homogeneity of the samples.
{"title":"Thermal, Chemical, and Morphological Characterization of Microcellular Polyurethane Elastomers","authors":"Marcos F. M. Pacheco, O. Bianchi, R. Fiorio, A. J. Zattera, M. Zeni, M. Giovanela, J. S. Crespo","doi":"10.1177/0095244309095016","DOIUrl":"https://doi.org/10.1177/0095244309095016","url":null,"abstract":"In this study, three different microcellular polyurethane elastomers (MPUE) based on 4,4'-diphenylmethane diisocyanate with different rigid segment contents are prepared (Formulations 1, 2, and 3 with 32, 35, and 42% of rigid segment content, respectively). The MPUE are obtained through a two-step method using a prepolymer system. The samples are analyzed to determine their thermal, morphological, and chemical properties. The thermogravimetric analysis indicates the presence of two degradation stages, referring to the rigid and flexible phases, respectively. The differential scanning calorimetry tests indicate that for the MPUE there was an increase in the glass transition temperature of the flexible phase with an increase in the percent of the rigid phase. An increase in the quantity of the rigid phase present in the MPUE results in greater values for the crosslink density, which in turn results in an increase in the rigidity of the material. The scanning electron microscopy micrographs indicated a large number of closed cells and that a higher rigid segment content give a better cell homogeneity of the samples.","PeriodicalId":15644,"journal":{"name":"Journal of Elastomers and Plastics","volume":"81 1","pages":"323 - 338"},"PeriodicalIF":1.7,"publicationDate":"2009-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76098941","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2009-06-03DOI: 10.1177/0095244309104462
A. Othman
The impact of moisture-induced damage on the fracture resistance of rubber-modified hot mix asphalt (HMA) mixture as determined by the critical energy release rate (Jc) was investigated. Crumb rubber content of 15% by weight of binder was adapted. Semi-circular core specimens (76 mm radius and 57 mm thickness) were used for fracture resistance tests. An accelerated moisture damage program was established to evaluate the mixture resistance to moisture damage. Tested specimens were immersed in a water bath at a controlled temperature of 25°C under vacuum of 510 mm Hg at different moisture treatment periods of 0, 1, 2, and 7 days. A relationship between the moisture treatment period and the critical energy release rate was determined. The current investigation revealed a reduction on the fracture resistance and mechanical performance of the moisture treated mixtures. The reduction increased with the increase of moisture treatment period. The results also indicated significant improvement in mix stability, strength, and resistance to fracture and moisture damage when crumb rubber was applied to HMA mixtures.
以临界能量释放率(Jc)为指标，研究了湿损伤对橡胶改性热混合沥青(HMA)混合料抗断裂性能的影响。胶结剂的胶屑含量为重量比的15%。采用半径为76 mm、厚度为57 mm的半圆形岩心试件进行抗断裂试验。建立了加速湿损伤程序，对混合料的抗湿损伤性能进行了评价。在温度控制在25°C的水浴中，在510 mm Hg的真空条件下浸泡，不同的水分处理时间分别为0、1、2和7天。确定了水分处理时间与临界能量释放率之间的关系。目前的研究表明，经过水分处理的混合物的抗断裂性能和力学性能有所降低。随着水分处理时间的延长，降低幅度增大。结果还表明，将橡胶屑加入HMA混合料中，可显著改善混合料的稳定性、强度以及抗断裂和抗湿损伤性。
{"title":"Effect of Moisture-induced Damage on Fracture Resistance of Rubber-modified HMA Mixtures","authors":"A. Othman","doi":"10.1177/0095244309104462","DOIUrl":"https://doi.org/10.1177/0095244309104462","url":null,"abstract":"The impact of moisture-induced damage on the fracture resistance of rubber-modified hot mix asphalt (HMA) mixture as determined by the critical energy release rate (Jc) was investigated. Crumb rubber content of 15% by weight of binder was adapted. Semi-circular core specimens (76 mm radius and 57 mm thickness) were used for fracture resistance tests. An accelerated moisture damage program was established to evaluate the mixture resistance to moisture damage. Tested specimens were immersed in a water bath at a controlled temperature of 25°C under vacuum of 510 mm Hg at different moisture treatment periods of 0, 1, 2, and 7 days. A relationship between the moisture treatment period and the critical energy release rate was determined. The current investigation revealed a reduction on the fracture resistance and mechanical performance of the moisture treated mixtures. The reduction increased with the increase of moisture treatment period. The results also indicated significant improvement in mix stability, strength, and resistance to fracture and moisture damage when crumb rubber was applied to HMA mixtures.","PeriodicalId":15644,"journal":{"name":"Journal of Elastomers and Plastics","volume":"6 1","pages":"401 - 414"},"PeriodicalIF":1.7,"publicationDate":"2009-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81842072","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2009-06-03DOI: 10.1177/0095244309105248
S. Qamar, S. Al-Hiddabi, T. Pervez, F. Marketz
Elastomers are being increasingly used for sealing and other applications in the oil and gas industry. Specifically developed elastomers possess durable properties and have the ability to withstand detrimental effects of heat, chemicals, and harsh environments. For successful modeling and simulation of various downhole processes, it is very important to determine the behavior of elastomer materials under realistic well conditions. Of special interest is the class known as swelling elastomers. This article reports some results from experiments conducted on mechanical testing and characterization of an inert (nonswelling) and a water-swelling elastomer (both belonging to the EPDM family) used for sealing purposes by a local petroleum development firm. Experiments were designed and conducted in accordance with standard ASTM test methods. Apart from regularly available testing equipment, some simple test rigs and fixtures were designed and fabricated. Elastomer behavior was tested for hardness, compression set (at different temperatures and for different periods of time), tensile set (for different periods of time), tensile properties (fracture strength and percent elongation), and swelling. In the swelling test, different sample geometries (unconfined samples and samples mounted on steel plate) were tested for a total duration of 1000 h (roughly 45 days) in salt solutions of different concentrations and at different temperatures. Results show that compression set increases with increasing temperature and testing time, while room temperature tensile set also increases with longer testing time. Compared to the inert elastomer (exhibiting nonlinear elastic behavior like normal rubbers), swelling elastomer surprisingly showed linear stress—strain response. As expected, the inert elastomer did not exhibit any change in volume, while the swelling elastomer showed significant volume/thickness increase with increasing test temperature and decreasing salt concentration.
{"title":"Mechanical Testing and Characterization of a Swelling Elastomer","authors":"S. Qamar, S. Al-Hiddabi, T. Pervez, F. Marketz","doi":"10.1177/0095244309105248","DOIUrl":"https://doi.org/10.1177/0095244309105248","url":null,"abstract":"Elastomers are being increasingly used for sealing and other applications in the oil and gas industry. Specifically developed elastomers possess durable properties and have the ability to withstand detrimental effects of heat, chemicals, and harsh environments. For successful modeling and simulation of various downhole processes, it is very important to determine the behavior of elastomer materials under realistic well conditions. Of special interest is the class known as swelling elastomers. This article reports some results from experiments conducted on mechanical testing and characterization of an inert (nonswelling) and a water-swelling elastomer (both belonging to the EPDM family) used for sealing purposes by a local petroleum development firm. Experiments were designed and conducted in accordance with standard ASTM test methods. Apart from regularly available testing equipment, some simple test rigs and fixtures were designed and fabricated. Elastomer behavior was tested for hardness, compression set (at different temperatures and for different periods of time), tensile set (for different periods of time), tensile properties (fracture strength and percent elongation), and swelling. In the swelling test, different sample geometries (unconfined samples and samples mounted on steel plate) were tested for a total duration of 1000 h (roughly 45 days) in salt solutions of different concentrations and at different temperatures. Results show that compression set increases with increasing temperature and testing time, while room temperature tensile set also increases with longer testing time. Compared to the inert elastomer (exhibiting nonlinear elastic behavior like normal rubbers), swelling elastomer surprisingly showed linear stress—strain response. As expected, the inert elastomer did not exhibit any change in volume, while the swelling elastomer showed significant volume/thickness increase with increasing test temperature and decreasing salt concentration.","PeriodicalId":15644,"journal":{"name":"Journal of Elastomers and Plastics","volume":"38 1","pages":"415 - 431"},"PeriodicalIF":1.7,"publicationDate":"2009-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82140266","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2009-05-01DOI: 10.1177/0095244308091524
Y. Tsai, P. Tsai, Yao-Tsu Wu, M. Leu, Jyh-Horng Wu
This study investigates the effects of different types of curatives at polypropylene (PP) and ethylene propylene diene monomer (EPDM) blend ratios (100 : 40 phr) in dynamically vulcanized products. The thermoplastic vulcanizates are prepared by batch melt mixing of PP with EPDM, using pheolic resin, dicumyl peroxide, hydrosilyation, and complex systems as curatives. Observed changes in curing characteristics and mechanical properties of blends have been correlated with phase morphology, as attested by scanning electron micrographs. On the basis of the obtained results, different curative systems control final vulcanizing characteristics, mechanical properties, morphology, intermolecular interaction, and thermal properties of EPDM/PP blends.
{"title":"Effect of Complex Curatives on the Properties for Ethylene Propylene Diene Rubber/Polypropylene Blends","authors":"Y. Tsai, P. Tsai, Yao-Tsu Wu, M. Leu, Jyh-Horng Wu","doi":"10.1177/0095244308091524","DOIUrl":"https://doi.org/10.1177/0095244308091524","url":null,"abstract":"This study investigates the effects of different types of curatives at polypropylene (PP) and ethylene propylene diene monomer (EPDM) blend ratios (100 : 40 phr) in dynamically vulcanized products. The thermoplastic vulcanizates are prepared by batch melt mixing of PP with EPDM, using pheolic resin, dicumyl peroxide, hydrosilyation, and complex systems as curatives. Observed changes in curing characteristics and mechanical properties of blends have been correlated with phase morphology, as attested by scanning electron micrographs. On the basis of the obtained results, different curative systems control final vulcanizing characteristics, mechanical properties, morphology, intermolecular interaction, and thermal properties of EPDM/PP blends.","PeriodicalId":15644,"journal":{"name":"Journal of Elastomers and Plastics","volume":"120 1","pages":"209 - 221"},"PeriodicalIF":1.7,"publicationDate":"2009-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77384201","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2009-05-01DOI: 10.1177/0095244308099553
N. Nakajima, E. R. Harrell
The coating speed of plastisol is limited to a shear rate below the instability, because the instability results in nonuniform coating. However, there is an indication that beyond instability region the flow stabilizes again at the very high shear rates. If a plastisol is made to flow through the completely enclosed die-assembly with filled channel and let the instability taking place there, a super-high speed coating may be possible at the postinstability region. Although this work does not involve actual experiments, it explores possible mechanisms of flow at the instability and the stable flow beyond. The relation between the inter-particle interaction, (either attractive, repulsive, or neutral) and the flow type, (either clustering or nonclustering flow) is explored in order to aid designing a new device and developing formulations suitable for its use.
{"title":"Rheology of PVC Plastisol at Instability Region and Beyond (Proposal for Super-High Shear-Rate Coating)","authors":"N. Nakajima, E. R. Harrell","doi":"10.1177/0095244308099553","DOIUrl":"https://doi.org/10.1177/0095244308099553","url":null,"abstract":"The coating speed of plastisol is limited to a shear rate below the instability, because the instability results in nonuniform coating. However, there is an indication that beyond instability region the flow stabilizes again at the very high shear rates. If a plastisol is made to flow through the completely enclosed die-assembly with filled channel and let the instability taking place there, a super-high speed coating may be possible at the postinstability region. Although this work does not involve actual experiments, it explores possible mechanisms of flow at the instability and the stable flow beyond. The relation between the inter-particle interaction, (either attractive, repulsive, or neutral) and the flow type, (either clustering or nonclustering flow) is explored in order to aid designing a new device and developing formulations suitable for its use.","PeriodicalId":15644,"journal":{"name":"Journal of Elastomers and Plastics","volume":"50 1","pages":"277 - 285"},"PeriodicalIF":1.7,"publicationDate":"2009-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82374177","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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