Rubber latex is an important economic resource. However, the residues from its harvesting are thrown away, even though they contain lipids that can be recycled. This recovery of the residues from the bottom of the cup...Rubber latex is an important economic resource. However, the residues from its harvesting are thrown away, even though they contain lipids that can be recycled. This recovery of the residues from the bottom of the cup requires first and foremost their characterization. The aim of this study is therefore to determine the main physical and chemical characteristics of rubber latex cup bottom oil. Oil’s physical parameters determination shows that it has a density of 951 kg∙m−3, a kinematic viscosity of 48.57 cSt and a water content of 0.0845%. Chemical parameters, meanwhile, indicate that this cup bottom residue has a fat content of 95.96%, an acid number of 2.805 mg KOH/g and an iodine number of 92.42 g I2/100g. Therefore, rubber latex cup bottom oil can be used in the formulation of biofuels, biolubricants, paints, varnishes, alkyd resins, polishing oils, soaps, and insecticides.展开更多
The application of phthalate plasticizers has been restricted around the world due to their poor migration and potential harm to the human body.Hence,producing functional bio-based plasticizers via exploiting clean an...The application of phthalate plasticizers has been restricted around the world due to their poor migration and potential harm to the human body.Hence,producing functional bio-based plasticizers via exploiting clean and reusable resources meets the satisfaction of current demands.In this study,flame-retardant rubber seed oil-based plasticize(FRP)was prepared via epoxidation reaction and ring opening addition reactions,which was used as a flame-resistant plasticizer for polyvinyl chloride to replace petroleum-based phthalate plasticizer.When DOP was replaced with FRP,the torque of PVC blends increased from 11.4 to 18.4 N⋅m,the LOI value increased from 24.3%for PVC-FRP-0%to 33.1%for PVC-FRP-20.The THR value diminished from 39 MJ/m^(2)(pertaining to PVC-FRC-0)to 22 MJ/m^(2)Tg increased from 23°C to 47°C,the weight loss of plasticized PVC blends significantly reduced from 22.6%to 2.8%in leaching tests.The study provided a new way to prepare flame retardant plasticizer using rubber seed oil as raw material.展开更多
Aromatic oil has been used to promote the properties of crumb rubber modified asphalt which is an ideal method to deal with the resource utilization of waste rubber tires and by-product of refinery. Furfural extract o...Aromatic oil has been used to promote the properties of crumb rubber modified asphalt which is an ideal method to deal with the resource utilization of waste rubber tires and by-product of refinery. Furfural extract oil(FEO) was separated into the light fraction and the heavy fraction. Swelling and dissolution process of natural rubber sheet in these three oil samples was investigated to shed light on the interaction mechanism. Crumb rubber also interacted on FEO and asphalt respectively. Energy dispersive spectrometer(EDS), thermo-gravimetric analysis(TGA) and scanning electron microscope(SEM) were used to characterize the chemical and structural properties of processed rubber. The chemical composition of processed oils and asphalt was investigated by using the hydrocarbon group analysis(SARA) and gel permeation chromatography. The results revealed that the swelling rate and mass loss of rubber in oils were much higher than those in asphalt and rose with an increasing processing temperature. The heavy fraction of FEO had more diffusion and dissolving capability than the light fraction, whilst compatibility was observed between the heavy fraction and the light fraction. Selective absorption was not observed in the study and detachment of dissolved rubber was disseminated from the outside to the inside. The cross-linking degree of the residue rubber was unchanged with the processing time, and sulfur predominantly remained in the undissolved rubber. Dissolution of crumbed rubber in oils was attributed to devulcanization, while that in the asphalt was mainly attributed to depolymerization.展开更多
In this study, tropical peat swamp soils from Giam Siak Kecil-Bukit Batu Biosphere Reserve (GSKBB) in Indonesia was evaluated to assess the impact of oil palm and rubber plantations on this unique organic soil through...In this study, tropical peat swamp soils from Giam Siak Kecil-Bukit Batu Biosphere Reserve (GSKBB) in Indonesia was evaluated to assess the impact of oil palm and rubber plantations on this unique organic soil through comparisons with soils from a natural forest using a polyphasic approach (chemical and molecular microbial assays). Changes in the ammonium, nitrate and phosphate concentration were observed in soils converted to agricultural use. Soil enzyme activities in plantation soils showed reduced β-glucosidase, cellobiohydrolase and acid phosphatase activities (50% - 55% decrease). PCR-DGGE based analysis showed that the soil bacterial community from agricultural soils exhibited the lowest similarity amongst the different microbial groups (fungi and Archaea) evaluated (34% similarity to the natural forest soil). Shannon Diversity index values showed that generally the conversion of tropical peatland natural forest to rubber plantation resulted in a greater impact on microbial diversity (ANOVA p < 0.05). Overall, this study indicated substantial shifts in the soil microbial activity and diversity upon conversion of natural peatland forest to agriculture, with a greater change being observed under rubber plantation compared to oil palm plantation. These findings provided important data for future peatland management by relating changes in the soil microbial community and activities associated to agricultural practices carried out on peatland.展开更多
In this paper,the surface activated crumb rubber with waste cooking oil(WCO)was studied to improve the performance of crumb rubber modified asphalt.The activated waste crumb rubber modified asphalt(OCRMA)with differen...In this paper,the surface activated crumb rubber with waste cooking oil(WCO)was studied to improve the performance of crumb rubber modified asphalt.The activated waste crumb rubber modified asphalt(OCRMA)with different amount of crumb rubber was prepared to study the microscopic appearance of OCRMA by scanning electron microscope and fluorescence microscope and analyze the surface performance.The rheological properties and microscopic mechanism of OCRMA were characterized by dynamic shear rheological test,multiple stress creep recovery(MSCR)test,BBR test and infrared spectroscopy.The results show that the dissolution degree of waste crumb rubber is improved after WCO activation,and the compatibility with asphalt components is enhanced,and the stable cross-linking structure is formed,which improves the asphalt performance.The several new absorption peaks,which were obvious,were all caused by the composition of WCO,that is,there was no significant chemical change during the interaction between the activated crumb rubber and base asphalt.Compared with the common waste crumb rubber modified asphalt(CRMA),activation with WCO can significantly reduce the viscosity of CRMA,decrease the difference of segregation softening point by 27%,and enhance the low temperature performance by 30%.The aging degree is greatly reduced,and the anti-aging performance of OCRMA is increased by about 20%with the same dosage.The high temperature performance,though higher than that of base asphalt,decreases to some extent.After comprehensive analysis,the optimal dosage of crumb rubber for OCRMA is 30%.展开更多
During the production of palm oil,a significant amount of waste is generated.However,because of inefficient handling and utilization,these wastes are becoming a larger issue.As a result,one initiative is to use these ...During the production of palm oil,a significant amount of waste is generated.However,because of inefficient handling and utilization,these wastes are becoming a larger issue.As a result,one initiative is to use these wastes in the pavement industry as sustainable materials.However,there is still a lack of understanding about the wider incorporation of palm oil waste in asphalt pavement and its performance.This study examines existing literature on the use of various wastes in the pavement industry,including palm oil clinker(POC),palm oil fibre(POF),palm kernel shell(PKS),and palm oil fuel ash(POFA).As a result,this paper presents a systematic review and scientometric investigation of related study publications on many uses of palm oil waste in the asphalt pavement industry and its performance from 2009 to 2022.The VOS viewer application was used to conduct the sciento-metric study analysis.The relationship between interactions detected in co-authored country studies cited sources of co-citation,and the keyword of the co-occurrence and publication source enabled the identification of the research gap.According to the systematic literature review,40%–60% POC can be used to fine aggregate for optimal performance,while 0–100%PKS can be used to replace coarse aggregate.In addition,50%–80% POFA or POC fine(POCF)can be used as a filler replacement,5%–8% POCF or POFA as a bitumen modifier,and 0.3% POF as a stabilizing additive.Furthermore,the study demonstrates that the safety of utilizing wastes with more than 50% CO_(2) emissions can be curtailed with minimal heavy metal leaching and radioactivity levels.The scientometric analysis may encourage researchers to seek out gaps in the literature that will aid in the long-term,multifaceted use of palm oil wastes in the asphalt pavement industry.Furthermore,the study recommends employing and researching the enormous potential of using palm oil waste in the pavement sectors because they are more sustainable and have better performance.However,there are some barriers to using palm oil waste in the asphalt pavement industry,such as a lack of design standards and guidelines,inefficient raw material pro-cessing conversion facilities,and large-scale production equipment.展开更多
Statistical analysis of product yield for biodiesel preparation by transesterification process was performed using the Minitab software. A standard RSM Design tool known as CCD was applied to study the transesterifica...Statistical analysis of product yield for biodiesel preparation by transesterification process was performed using the Minitab software. A standard RSM Design tool known as CCD was applied to study the transesterification reaction variables. The obtained parameters were verified experimentally for the transesterification reaction of rubber seed oil using solid metal oxide catalyst. The factors affecting the methyl ester yield during transesterification reaction were identified as the catalyst content, molar ratio of oil to alcohol and reaction time. High methyl ester yield and fast reaction rate could be obtained even if reaction temperature was relatively low, which is quite favorable to the industrial production of biodiesel from the rubber seed oil. 98.54% of methyl ester was formed from the transesterification of RSO with methanol. R-squared is a statistical measure of how close the data are to the fitted regression line. It is also known as the coefficient of determination, or the coefficient of multiple determination for multiple regression. In this study, an R<sup>2</sup> value of 0.98 is obtained.展开更多
The present communication addresses compatibility of two synthetic rubber types,chloroprene and nitrile-butadiene ones,with a number of base oils of petroleum origin and lubricating greases produced thereof.Four base ...The present communication addresses compatibility of two synthetic rubber types,chloroprene and nitrile-butadiene ones,with a number of base oils of petroleum origin and lubricating greases produced thereof.Four base oils,including three naphthenic products with varying degrees of refining and one paraffinic product,were compared with each other in terms of their effect on the rubbers.Degenerative changes occurring in the rubbers on contact with the oils and greases were studied using accelerated ageing tests.Alterations in rubber parameters,such as hardness,weight and glass transition temperature,caused by interaction with oil were monitored.The main physicochemical mechanisms standing behind the changes observed in the rubber properties were found to be(i) migration of plasticizer from rubber into the oil phase,(ii) absorption of oil by rubber,and(iii) oxidation of rubber.An increase in glass transition temperature(Tg) of rubber aged in a base oil or grease was considered as an indirect indication that the plasticizer had migrated out of rubber;the plasticizer accumulation in the oil phase being directly confirmed by gas chromatography.In order to suppress the plasticizer migration,oil additivation with dioctyl adipate(DOA),a common plasticizer used in rubber formulations,was attempted.However,the DOA-additivated oils,while reducing plasticizer migration,were found to cause more swelling than the original oils in the case of chloroprene rubber.As an alternative,replacement of DOA by an alkylated aryl phosphate in nitrile-butadiene rubber formulations was considered,but it did not solve the problem either.The results of this study suggest conclusively that the type of rubber,the plasticizer,and the base oil are all the crucial parameters that should be considered when matching rubber with oil in real-life applications.Interaction of rubber with base oils and with greases produced thereof is largely controlled by(i) solvency of the base oils and(ii) polarity and cross-linking density of the rubber matrix.Higher temperatures accelerate ageing in all cases.展开更多
Polar components play a very important role toward light stability of hydrotreated naphthenic rubber process oil. Polar components in hydrotreated naphthenic rubber process oil are analyzed in detail. Polar components...Polar components play a very important role toward light stability of hydrotreated naphthenic rubber process oil. Polar components in hydrotreated naphthenic rubber process oil are analyzed in detail. Polar components are firstly isolated from rubber process oil by column chromatography of silica gel, and then characterized by a series of instrument technology including elemental analysis, infrared spectroscopy, APCI/MS and XPS. The results show that the polar components comprise some hetero atoms compounds of sulfur, nitrogen and oxygen. Oxygen-containing compounds such as hydroxyl, carbonyl, and carboxyl groups constitute the main body of polar components. Nitrogen-containing compounds (NH2, NH, or NO2 and-N=N-) and sulfur-containing compounds (SO42- and PHSSPH) only account for minor percent of polar components. The molecular weight distribution of polar components mainly concentrates between 300 and 500 and a minor portion distributes from 180 to 300.展开更多
Kaolin was modified using a chemical complex of hydrazine hydrate and oleochemical sodium salts derived from rubber seed oil (SRSO) and tea seed oil (STSO) respectively. Characterization of the pristine kaolin and the...Kaolin was modified using a chemical complex of hydrazine hydrate and oleochemical sodium salts derived from rubber seed oil (SRSO) and tea seed oil (STSO) respectively. Characterization of the pristine kaolin and the modified kaolins were performed using Scanning Electron Microscopy (SEM), Simultaneous Thermogravimetric/Differential Thermal Analysis (TG/DTA) and UV Spectrophotometry. TG/DTA revealed that the incorporation of the oleochemical salts enhanced thermal decomposition of kaolin into metakaolin. Ultraviolet spectrophotometric studies conducted on the modified kaolin show for the first time that the SRSO-modified kaolin and STSO-modified kaolin have a peak absorbance wavelengths of 312.72 nm and 314.26 nm respectively. This shows that the modified kaolin is a promising candidate for sunscreen applications.展开更多
The development of biofuels is driven both by concern about the greenhouse effect and by interest in the opportunities for exploitation of biomass of agricultural origin. In order to improve the yield and quality of b...The development of biofuels is driven both by concern about the greenhouse effect and by interest in the opportunities for exploitation of biomass of agricultural origin. In order to improve the yield and quality of biodiesel through modeling and optimization, several studies are in progress. In this paper, biodiesel produced from rubber seed oil in the homogeneous transesterification is studied using a Plackett-Burman experimental design, a full factorial design, a central composite design and an Artificial Neural Network (ANN) coupled with a Genetic Algorithm (GA).Variables such as temperature, stirring speed, reaction time, type of alcohol, and type of catalyst are studied to obtain the best specific gravity and kinematic viscosity. Type of alcohol and type of catalyst have the greatest effect on the two responses, with ethanol (alcohol) and sulphuric acid (catalyst) producing the best results. The specific gravity and kinematic viscosity changes recorded during the transesterification process followed the first and second order polynomial models, respectively. The ANN coupled with GA was used to optimize the two responses simultaneously. Global optimal values of specific gravity (0.883) and kinematic viscosity (6.76 cSt) were recorded when a temperature of 90°C, a stirring speed of 305 rpm, and a treatment time of 141 min were imposed.展开更多
Four oil absorbents based on styrene butadiene (SBR), i.e., pure SBR (PS), 4. tert-butylstyrene-SBR (PBS), EPDM-SBR network (PES) and 4.tert-butylstyrene-EPDMSBR (PBES), were produced from crosslinking polymerization ...Four oil absorbents based on styrene butadiene (SBR), i.e., pure SBR (PS), 4. tert-butylstyrene-SBR (PBS), EPDM-SBR network (PES) and 4.tert-butylstyrene-EPDMSBR (PBES), were produced from crosslinking polymerization of uncured styrene butadiene rubber (SBR), 4-tert-butylstyrene (tBS) and ethylene-propylenc-diene terpolymer (EPDM). The reaction took place in toluene using benzoyl peroxide (BPO) as an initiator. Uncured SBR was used as both a pre-polymer and a crosslink agent in this work, and the crosslinked polymer was identified by IR spectroscopy. The oil absorbency of the crosslinked polymer was evaluated with the method ASTM (F726-81). The order of maximum oil absorbency was PBES>PBS>PES>PS. The maximum values of oil absorbency of PBES and PBS were 74.0g/g and 69.5g/g, respectively. Gel fractions and swelling kinetic constants, however, had the opposite sequences. The swelling kinetic constant of PS evaluated by an experimental equation was 49. 97×10^(-2)h^(-1).展开更多
文摘Rubber latex is an important economic resource. However, the residues from its harvesting are thrown away, even though they contain lipids that can be recycled. This recovery of the residues from the bottom of the cup requires first and foremost their characterization. The aim of this study is therefore to determine the main physical and chemical characteristics of rubber latex cup bottom oil. Oil’s physical parameters determination shows that it has a density of 951 kg∙m−3, a kinematic viscosity of 48.57 cSt and a water content of 0.0845%. Chemical parameters, meanwhile, indicate that this cup bottom residue has a fat content of 95.96%, an acid number of 2.805 mg KOH/g and an iodine number of 92.42 g I2/100g. Therefore, rubber latex cup bottom oil can be used in the formulation of biofuels, biolubricants, paints, varnishes, alkyd resins, polishing oils, soaps, and insecticides.
基金funded by the Science and Technology Project of Henan Province(202102310593)and Science and Technology Project of Kaifeng City(2002003).
文摘The application of phthalate plasticizers has been restricted around the world due to their poor migration and potential harm to the human body.Hence,producing functional bio-based plasticizers via exploiting clean and reusable resources meets the satisfaction of current demands.In this study,flame-retardant rubber seed oil-based plasticize(FRP)was prepared via epoxidation reaction and ring opening addition reactions,which was used as a flame-resistant plasticizer for polyvinyl chloride to replace petroleum-based phthalate plasticizer.When DOP was replaced with FRP,the torque of PVC blends increased from 11.4 to 18.4 N⋅m,the LOI value increased from 24.3%for PVC-FRP-0%to 33.1%for PVC-FRP-20.The THR value diminished from 39 MJ/m^(2)(pertaining to PVC-FRC-0)to 22 MJ/m^(2)Tg increased from 23°C to 47°C,the weight loss of plasticized PVC blends significantly reduced from 22.6%to 2.8%in leaching tests.The study provided a new way to prepare flame retardant plasticizer using rubber seed oil as raw material.
文摘Aromatic oil has been used to promote the properties of crumb rubber modified asphalt which is an ideal method to deal with the resource utilization of waste rubber tires and by-product of refinery. Furfural extract oil(FEO) was separated into the light fraction and the heavy fraction. Swelling and dissolution process of natural rubber sheet in these three oil samples was investigated to shed light on the interaction mechanism. Crumb rubber also interacted on FEO and asphalt respectively. Energy dispersive spectrometer(EDS), thermo-gravimetric analysis(TGA) and scanning electron microscope(SEM) were used to characterize the chemical and structural properties of processed rubber. The chemical composition of processed oils and asphalt was investigated by using the hydrocarbon group analysis(SARA) and gel permeation chromatography. The results revealed that the swelling rate and mass loss of rubber in oils were much higher than those in asphalt and rose with an increasing processing temperature. The heavy fraction of FEO had more diffusion and dissolving capability than the light fraction, whilst compatibility was observed between the heavy fraction and the light fraction. Selective absorption was not observed in the study and detachment of dissolved rubber was disseminated from the outside to the inside. The cross-linking degree of the residue rubber was unchanged with the processing time, and sulfur predominantly remained in the undissolved rubber. Dissolution of crumbed rubber in oils was attributed to devulcanization, while that in the asphalt was mainly attributed to depolymerization.
文摘In this study, tropical peat swamp soils from Giam Siak Kecil-Bukit Batu Biosphere Reserve (GSKBB) in Indonesia was evaluated to assess the impact of oil palm and rubber plantations on this unique organic soil through comparisons with soils from a natural forest using a polyphasic approach (chemical and molecular microbial assays). Changes in the ammonium, nitrate and phosphate concentration were observed in soils converted to agricultural use. Soil enzyme activities in plantation soils showed reduced β-glucosidase, cellobiohydrolase and acid phosphatase activities (50% - 55% decrease). PCR-DGGE based analysis showed that the soil bacterial community from agricultural soils exhibited the lowest similarity amongst the different microbial groups (fungi and Archaea) evaluated (34% similarity to the natural forest soil). Shannon Diversity index values showed that generally the conversion of tropical peatland natural forest to rubber plantation resulted in a greater impact on microbial diversity (ANOVA p < 0.05). Overall, this study indicated substantial shifts in the soil microbial activity and diversity upon conversion of natural peatland forest to agriculture, with a greater change being observed under rubber plantation compared to oil palm plantation. These findings provided important data for future peatland management by relating changes in the soil microbial community and activities associated to agricultural practices carried out on peatland.
基金This study was supported by Hunan Provincial Natural Science Foundation(Project No.2021JJ30709)Changsha Municipal Natural Science Foundation(Project No.kq2007029)Practice Innovation and Entrepreneurship Enhancement Program for Postgraduate of Changsha University of Science&Technology(Project No.SJCX202112).
文摘In this paper,the surface activated crumb rubber with waste cooking oil(WCO)was studied to improve the performance of crumb rubber modified asphalt.The activated waste crumb rubber modified asphalt(OCRMA)with different amount of crumb rubber was prepared to study the microscopic appearance of OCRMA by scanning electron microscope and fluorescence microscope and analyze the surface performance.The rheological properties and microscopic mechanism of OCRMA were characterized by dynamic shear rheological test,multiple stress creep recovery(MSCR)test,BBR test and infrared spectroscopy.The results show that the dissolution degree of waste crumb rubber is improved after WCO activation,and the compatibility with asphalt components is enhanced,and the stable cross-linking structure is formed,which improves the asphalt performance.The several new absorption peaks,which were obvious,were all caused by the composition of WCO,that is,there was no significant chemical change during the interaction between the activated crumb rubber and base asphalt.Compared with the common waste crumb rubber modified asphalt(CRMA),activation with WCO can significantly reduce the viscosity of CRMA,decrease the difference of segregation softening point by 27%,and enhance the low temperature performance by 30%.The aging degree is greatly reduced,and the anti-aging performance of OCRMA is increased by about 20%with the same dosage.The high temperature performance,though higher than that of base asphalt,decreases to some extent.After comprehensive analysis,the optimal dosage of crumb rubber for OCRMA is 30%.
文摘During the production of palm oil,a significant amount of waste is generated.However,because of inefficient handling and utilization,these wastes are becoming a larger issue.As a result,one initiative is to use these wastes in the pavement industry as sustainable materials.However,there is still a lack of understanding about the wider incorporation of palm oil waste in asphalt pavement and its performance.This study examines existing literature on the use of various wastes in the pavement industry,including palm oil clinker(POC),palm oil fibre(POF),palm kernel shell(PKS),and palm oil fuel ash(POFA).As a result,this paper presents a systematic review and scientometric investigation of related study publications on many uses of palm oil waste in the asphalt pavement industry and its performance from 2009 to 2022.The VOS viewer application was used to conduct the sciento-metric study analysis.The relationship between interactions detected in co-authored country studies cited sources of co-citation,and the keyword of the co-occurrence and publication source enabled the identification of the research gap.According to the systematic literature review,40%–60% POC can be used to fine aggregate for optimal performance,while 0–100%PKS can be used to replace coarse aggregate.In addition,50%–80% POFA or POC fine(POCF)can be used as a filler replacement,5%–8% POCF or POFA as a bitumen modifier,and 0.3% POF as a stabilizing additive.Furthermore,the study demonstrates that the safety of utilizing wastes with more than 50% CO_(2) emissions can be curtailed with minimal heavy metal leaching and radioactivity levels.The scientometric analysis may encourage researchers to seek out gaps in the literature that will aid in the long-term,multifaceted use of palm oil wastes in the asphalt pavement industry.Furthermore,the study recommends employing and researching the enormous potential of using palm oil waste in the pavement sectors because they are more sustainable and have better performance.However,there are some barriers to using palm oil waste in the asphalt pavement industry,such as a lack of design standards and guidelines,inefficient raw material pro-cessing conversion facilities,and large-scale production equipment.
文摘Statistical analysis of product yield for biodiesel preparation by transesterification process was performed using the Minitab software. A standard RSM Design tool known as CCD was applied to study the transesterification reaction variables. The obtained parameters were verified experimentally for the transesterification reaction of rubber seed oil using solid metal oxide catalyst. The factors affecting the methyl ester yield during transesterification reaction were identified as the catalyst content, molar ratio of oil to alcohol and reaction time. High methyl ester yield and fast reaction rate could be obtained even if reaction temperature was relatively low, which is quite favorable to the industrial production of biodiesel from the rubber seed oil. 98.54% of methyl ester was formed from the transesterification of RSO with methanol. R-squared is a statistical measure of how close the data are to the fitted regression line. It is also known as the coefficient of determination, or the coefficient of multiple determination for multiple regression. In this study, an R<sup>2</sup> value of 0.98 is obtained.
文摘The present communication addresses compatibility of two synthetic rubber types,chloroprene and nitrile-butadiene ones,with a number of base oils of petroleum origin and lubricating greases produced thereof.Four base oils,including three naphthenic products with varying degrees of refining and one paraffinic product,were compared with each other in terms of their effect on the rubbers.Degenerative changes occurring in the rubbers on contact with the oils and greases were studied using accelerated ageing tests.Alterations in rubber parameters,such as hardness,weight and glass transition temperature,caused by interaction with oil were monitored.The main physicochemical mechanisms standing behind the changes observed in the rubber properties were found to be(i) migration of plasticizer from rubber into the oil phase,(ii) absorption of oil by rubber,and(iii) oxidation of rubber.An increase in glass transition temperature(Tg) of rubber aged in a base oil or grease was considered as an indirect indication that the plasticizer had migrated out of rubber;the plasticizer accumulation in the oil phase being directly confirmed by gas chromatography.In order to suppress the plasticizer migration,oil additivation with dioctyl adipate(DOA),a common plasticizer used in rubber formulations,was attempted.However,the DOA-additivated oils,while reducing plasticizer migration,were found to cause more swelling than the original oils in the case of chloroprene rubber.As an alternative,replacement of DOA by an alkylated aryl phosphate in nitrile-butadiene rubber formulations was considered,but it did not solve the problem either.The results of this study suggest conclusively that the type of rubber,the plasticizer,and the base oil are all the crucial parameters that should be considered when matching rubber with oil in real-life applications.Interaction of rubber with base oils and with greases produced thereof is largely controlled by(i) solvency of the base oils and(ii) polarity and cross-linking density of the rubber matrix.Higher temperatures accelerate ageing in all cases.
文摘Polar components play a very important role toward light stability of hydrotreated naphthenic rubber process oil. Polar components in hydrotreated naphthenic rubber process oil are analyzed in detail. Polar components are firstly isolated from rubber process oil by column chromatography of silica gel, and then characterized by a series of instrument technology including elemental analysis, infrared spectroscopy, APCI/MS and XPS. The results show that the polar components comprise some hetero atoms compounds of sulfur, nitrogen and oxygen. Oxygen-containing compounds such as hydroxyl, carbonyl, and carboxyl groups constitute the main body of polar components. Nitrogen-containing compounds (NH2, NH, or NO2 and-N=N-) and sulfur-containing compounds (SO42- and PHSSPH) only account for minor percent of polar components. The molecular weight distribution of polar components mainly concentrates between 300 and 500 and a minor portion distributes from 180 to 300.
文摘Kaolin was modified using a chemical complex of hydrazine hydrate and oleochemical sodium salts derived from rubber seed oil (SRSO) and tea seed oil (STSO) respectively. Characterization of the pristine kaolin and the modified kaolins were performed using Scanning Electron Microscopy (SEM), Simultaneous Thermogravimetric/Differential Thermal Analysis (TG/DTA) and UV Spectrophotometry. TG/DTA revealed that the incorporation of the oleochemical salts enhanced thermal decomposition of kaolin into metakaolin. Ultraviolet spectrophotometric studies conducted on the modified kaolin show for the first time that the SRSO-modified kaolin and STSO-modified kaolin have a peak absorbance wavelengths of 312.72 nm and 314.26 nm respectively. This shows that the modified kaolin is a promising candidate for sunscreen applications.
文摘The development of biofuels is driven both by concern about the greenhouse effect and by interest in the opportunities for exploitation of biomass of agricultural origin. In order to improve the yield and quality of biodiesel through modeling and optimization, several studies are in progress. In this paper, biodiesel produced from rubber seed oil in the homogeneous transesterification is studied using a Plackett-Burman experimental design, a full factorial design, a central composite design and an Artificial Neural Network (ANN) coupled with a Genetic Algorithm (GA).Variables such as temperature, stirring speed, reaction time, type of alcohol, and type of catalyst are studied to obtain the best specific gravity and kinematic viscosity. Type of alcohol and type of catalyst have the greatest effect on the two responses, with ethanol (alcohol) and sulphuric acid (catalyst) producing the best results. The specific gravity and kinematic viscosity changes recorded during the transesterification process followed the first and second order polynomial models, respectively. The ANN coupled with GA was used to optimize the two responses simultaneously. Global optimal values of specific gravity (0.883) and kinematic viscosity (6.76 cSt) were recorded when a temperature of 90°C, a stirring speed of 305 rpm, and a treatment time of 141 min were imposed.
文摘Four oil absorbents based on styrene butadiene (SBR), i.e., pure SBR (PS), 4. tert-butylstyrene-SBR (PBS), EPDM-SBR network (PES) and 4.tert-butylstyrene-EPDMSBR (PBES), were produced from crosslinking polymerization of uncured styrene butadiene rubber (SBR), 4-tert-butylstyrene (tBS) and ethylene-propylenc-diene terpolymer (EPDM). The reaction took place in toluene using benzoyl peroxide (BPO) as an initiator. Uncured SBR was used as both a pre-polymer and a crosslink agent in this work, and the crosslinked polymer was identified by IR spectroscopy. The oil absorbency of the crosslinked polymer was evaluated with the method ASTM (F726-81). The order of maximum oil absorbency was PBES>PBS>PES>PS. The maximum values of oil absorbency of PBES and PBS were 74.0g/g and 69.5g/g, respectively. Gel fractions and swelling kinetic constants, however, had the opposite sequences. The swelling kinetic constant of PS evaluated by an experimental equation was 49. 97×10^(-2)h^(-1).