Chakrit Sirisinha | Mahidol University (original) (raw)

Papers by Chakrit Sirisinha

Research paper thumbnail of A study to develop plastic magnets based on poly (vinyl chloride) and barium ferrite composites

Research paper thumbnail of Chitosan/xanthan gum porous scaffolds incorporated with in-situ-formed poly(lactic acid) particles: Their fabrication and ability to adsorb anionic compounds

Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2020

Research paper thumbnail of Physicoelectrical Properties and Piezoresistive Sensing of the Extrusion-Based Conductive Rubber Composites: Simultaneous Effects of the Extrusion Parameters

Rubber Chemistry and Technology, 2020

Flexible conductive rubber composites (CRCs) were prepared based on carbon black–filled oil-exten... more Flexible conductive rubber composites (CRCs) were prepared based on carbon black–filled oil-extended styrene–butadiene rubber soft matrix. Using a variety of screw designs, the simultaneous effects of the twin-screw extrusion parameters (i.e., kneading element, dispersing position, and screw speed) on the physicoelectrical properties of the CRCs were investigated statistically. The increased intenseness of the extrusion parameters significantly enhances the piezoresistive sensing via the improved filler dispersion, increased rubber–filler interaction, and weakened filler–filler networks. Nevertheless, the influence of the kneading elements on the properties of the CRCs significantly decreases with an increase in the intenseness of the dispersing position or the screw speed, referred to as a “negative interaction.” An extreme intenseness of the screw design causes the excellent piezoresistive sensing of the CRCs, but with undesirable mechanical strength. Because those properties need...

Research paper thumbnail of Cure retardation of peroxide-cured silica filled natural rubber influenced by organosilane

Polymer Engineering & Science, 2018

The influence of silane coupling agent on properties of silica-filled compounds under peroxide cu... more The influence of silane coupling agent on properties of silica-filled compounds under peroxide curing was investigated. bis (triethoxysilylpropyl) tetrasulfide (TESPT) was selected in this study and its content was varied from 0 to 12% w/w of silica. It is found that with increasing TESPT content, bound rubber content, tensile strength, elongation at break and tear strength are enhanced. By contrast, magnitude of Payne's effect, modulus at 100% elongation (M 100) and heat build-up are decreased. The changes of such properties are attributed to the reduction of crosslink density in conjunction with the improvements of both rubber-filler interaction and degree of filler dispersion with increasing TESPT content in the peroxide curing system.

Research paper thumbnail of Influences of Styrene Butadiene Rubber and Silica Types on Performance of Passenger Car Radial Tire Tread

Rubber Chemistry and Technology, 2017

ABSTRACTA performance comparison among three types of styrene butadiene rubber (SBR), that is, em... more ABSTRACTA performance comparison among three types of styrene butadiene rubber (SBR), that is, emulsion polymerized SBR (ESBR), solution polymerized SBR (SSBR), and functionalized solution polymerized SBR (F-SSBR), was of interest. Effect of silica type, that is, highly dispersible silica and conventional precipitated silica, was also investigated. It is found that SSBR demonstrates significantly better heat build-up, dynamic set, abrasion resistance, including wet grip (WG) with comparable fuel efficiency, as compared to ESBR. As expected, the best tire performance, that is, abrasion resistance, WG, and fuel efficiency, is found in F-SSBR vulcanizates, attributed mainly to the greatest improvement in magnitude of rubber–filler interaction and degree of filler dispersion. Results reveal that the reactive functional group, that is, propylaminedimethoxysilane, which is chemically anchored at chain ends of F-SSBR, plays a crucial role in tire performance. Unexpectedly, silica type does...

Research paper thumbnail of Reinforcement of Multiwalled Carbon Nanotube in Nitrile Rubber: In Comparison with Carbon Black, Conductive Carbon Black, and Precipitated Silica

Journal of Nanomaterials, 2016

The properties of nitrile rubber (NBR) reinforced by multiwalled carbon nanotube (MWCNT), conduct... more The properties of nitrile rubber (NBR) reinforced by multiwalled carbon nanotube (MWCNT), conductive carbon black (CCB), carbon black (CB), and precipitated silica (PSi) were investigated via viscoelastic behavior, bound rubber content, electrical properties, cross-link density, and mechanical properties. The filler content was varied from 0 to 15 phr. MWCNT shows the greatest magnitude of reinforcement considered in terms of tensile strength, modulus, hardness, and abrasion resistance followed by CCB, CB, and PSi. The MWCNT filled system also exhibits extremely high levels of filler network and trapped rubber even at relatively low loading (5 phr) leading to high electrical properties and poor dynamic mechanical properties. Although CCB possesses the highest specific surface area, it gives lower level of filler network than MWCNT and also gives the highest elongation at break among all fillers. Both CB and PSi show comparable degree of reinforcement which is considerably lower than...

Research paper thumbnail of Properties of poly(lactic acid)/cellulose nanofiber biocomposites: Effect of polymeric plasticizers

Materials Today: Proceedings

Research paper thumbnail of Rejuvenating the structure and rheological properties of silica nanocomposites based on natural rubber

Polymer

The antagonistic effect of processing and thermal annealing on both the filler structure and the ... more The antagonistic effect of processing and thermal annealing on both the filler structure and the polymer matrix is explored in polymer nanocomposites based on natural rubber with precipitated silica incorporated by coagulation from aqueous suspension followed by roll-milling. Their structure and linear and non-linear rheology have been studied, with a particular emphasis on the effect of high temperature thermal treatment and the number of milling passes. Small-angle X-ray scattering intensities show that the silica is organized in small, unbreakable aggregates containing ca. 50 primary nanoparticles, which are reorganized on a larger scale in filler networks percolating at the highest silica contents. As expected, the filler network structure is found to be sensitive to milling, more milling inducing rupture, as evidenced by the decreasing Payne effect. After thermal treatment, the nanocomposite structure is found to be rejuvenated, erasing the effect of the previous milling on the low-strain modulus. In parallel, the dynamics of the samples described by the rheology or the calorimetric glass-transition temperature remain unchanged, whereas the natural latex polymer network structure is modified by milling towards a more fluid-like rheology, and cannot be recovered.

Research paper thumbnail of Performance Comparison of Various Surface Modifying Agents on Properties of Silica-Filled Neoprene Rubber

Rubber Chemistry and Technology, 2016

Influence of the surface modifying agents (SMAs) polyethylene glycol (PEG), 3-aminopropyl trietho... more Influence of the surface modifying agents (SMAs) polyethylene glycol (PEG), 3-aminopropyl triethoxysilane (APTES), and bis-(3-triethoxysilylpropyl)tetrasulfide (TESPT) on properties of silica-filled chloroprene rubber (CR) was investigated. Results reveal that the presence of SMAs greatly improves mechanical and dynamic properties of the silica-filled CR because of the reduced filler–filler interaction and improved rubber–filler interaction as evidenced by the Payne effect and bound rubber content results, respectively. When compared at the same SMA dosage, TESPT gives the best overall vulcanizate properties. This effect is attributed to high coupling efficiency of TESPT and its ability to donate sulfur atoms during vulcanization, leading to the improved filler dispersion, rubber–filler interaction, and cross-link density. APTES gives high coupling efficiency, but because of the lack of sulfur atoms, its performance is slightly inferior to that of TESPT. In contrast, PEG can only re...

Research paper thumbnail of Influence of Carbon Black/Silica Hybrid Ratio on Properties of Passenger Car Tire Sidewall

Periodica Polytechnica Chemical Engineering

Influence of carbon black (CB)/precipitated silica (SiO2) hybrid ratio on properties of a passeng... more Influence of carbon black (CB)/precipitated silica (SiO2) hybrid ratio on properties of a passenger car tire (PCT) sidewall based on natural rubber (NR) and butadiene rubber (BR) blend was investigated. Rubbers filled with various hybrid filler ratios at a constant loading of 50 phr were prepared and tested. The filler reinforcement efficiency in association with crucial properties of the tire sidewall were of interest. Results show the enhanced rubber–filler interaction with increasing SiO2 fraction leading to the improvement in many vulcanizate properties including hardness, tensile strength, tear strength and fatigue resistance, at the expense of cure efficiency and hysteretic behaviors (i.e., reduced heat build-up resistance and increased dynamic set). The results also suggest the improvement in tire sidewall performance of the NR/BR vulcanizates reinforced with CB/SiO2 hybrid filler, compared to that of the CB-filled vulcanizate.

Research paper thumbnail of The influence of modified soybean oil as processing aids in tire application

Research paper thumbnail of Effects of Blend Ratio and SBR Type on Properties of Carbon Black-Filled and Silica-Filled SBR/BR Tire Tread Compounds

Advances in Materials Science and Engineering

This work aimed at investigating the effects of blend ratio between styrene butadiene rubber (SBR... more This work aimed at investigating the effects of blend ratio between styrene butadiene rubber (SBR) and butadiene rubber (BR) and SBR type (E-SBR and S-SBR) on properties of SBR/BR tire tread compounds. Influences of these parameters on properties of the tread compounds reinforced by 80 parts per hundred rubber (phr) of carbon black (CB) and silica were also compared. Results reveal that hardness, strengths, and wet grip efficiency were impaired whereas rolling resistance was improved with increasing BR proportion. Surprisingly, the presence of BR imparted poorer abrasion resistance in most systems, except for the CB-filled E-SBR system in which an enhanced abrasion resistance was observed. Obviously, S-SBR gave superior properties (tire performance) compared to E-SBR, particularly obvious in the silica-filled system. Compared with CB, silica gave comparable strengths, better wet grip efficiency, and lower rolling resistance. Carbon black, however, offered greater abrasion resistance...

Research paper thumbnail of Assessment of crosslink network and network defects of unfilled and filled ethylene-propylene-diene terpolymer using solid state nuclear magnetic relaxation spectroscopy

Journal of Applied Polymer Science

Research paper thumbnail of An efficient highly flexible strain sensor: Enhanced electrical conductivity, piezoresistivity and flexibility of a strongly piezoresistive composite based on conductive carbon black and an ionic liquid

Composites Part A: Applied Science and Manufacturing

Research paper thumbnail of Cure and scorch in the processing of ethylene-propylene-diene terpolymer (EPDM)

Journal of Applied Polymer Science

Research paper thumbnail of A Study of Carbon Black Distribution and Properties in BR/NBR Blends: Roles of Commercial Homogenizer and Slipping Agent

Polymer Plastics Technology and Engineering, 2001

Effects of commercial processing aids, Struktol NS60 (hydrocarbon resin) homogenizer and Struktol... more Effects of commercial processing aids, Struktol NS60 (hydrocarbon resin) homogenizer and Struktol WB16 (a mixture of metal salt and a fatty acid amide) slipping agent on the distribution of carbon black and physical properties in BR/NBR blends have been investigated. It was found that Struktol 60NS and Struktol WB16 in blend systems migrate preferentially to BR phase due to the strong interaction between Struktol and BR phase, leading to a decrease in viscosity of BR phase and thus an increase in carbon black residing in BR phase. Mechanical properties of unfilled compounds are strongly affected by blend ratio and loading of processing aids. However, in the case of filled compounds, the influence of carbon black distribution in each phase of the blends override those blend ratio and additive loading effects.

Research paper thumbnail of Effect of Compatibilizers on Rheology, Crosslink Density and Mechanical Properties of NR/NBR Blend

วารสารวิจัยและพัฒนา มจธ, 2007

Research paper thumbnail of Cure and dynamic mechanical properties in peroxide-cured isoprene rubber: effects of stearic acid and amine-based antioxidant

European Polymer Journal, Aug 1, 2004

Peroxide-cured isoprene rubber with various amounts of stearic acid and N-isopropyl-N 0-phenyl-p-... more Peroxide-cured isoprene rubber with various amounts of stearic acid and N-isopropyl-N 0-phenyl-p-phenylenediamine (i-PPD) was prepared. Processability, cure and dynamic mechanical properties of compounds were investigated. It has been found that stearic acid affects only the uncured compounds in terms of processability by acting as a lubricant, and plays no significant role in curing and dynamic mechanical properties. By contrast, i-PPD as an aminebased antioxidant shows pronounced effect on processability, cure and dynamic mechanical properties. The addition of i-PPD up to 2 phr could increase Mooney viscosity due to a thermal stabilization during high shear mixing. Exceeding this concentration, i-PPD shows plasticizing effect leading to a decrease in Mooney viscosity. Additionally, it has been shown that the addition of i-PPD reduces the crosslink density affecting remarkably the dynamic mechanical properties of compounds.

Research paper thumbnail of Roles of silane coupling agents on properties of silica-filled polychloroprene

European Polymer Journal, Mar 1, 2006

Silane coupling agent is used extensively to improve reinforcing efficiency of silica. Recently, ... more Silane coupling agent is used extensively to improve reinforcing efficiency of silica. Recently, many types of silane coupling agents have been developed and their roles on reinforcing improvement have been studied in many types of rubbers. In the present study, roles of the two widely used silane coupling agents, i.e., bis-(3-triethoxysilylpropyl) tetrasulfane (Si-69) and 3-thiocyanatopropyl triethoxy silane (Si-264) were studied in silica-filled polychloroprene (CR). The results reveal that the presence of Si-69 and Si-264 improves significantly the processability of the rubber compounds. The improvement is more pronounced for Si-264 due to its lower molecular weight and, thus, viscosity. Surprisingly, the results show that Si-69 and Si-264 affect cure characteristics differently, i.e., Si-69 somewhat retards cure while Si-264 accelerates cure. However, both Si-69 and Si-264 result in an increased crosslink density of the vulcanizates. The presence of silane coupling agent also enhances the mechanical properties of the vulcanizates due to the combined effects of better filler dispersion, better rubber-filler interaction and increased crosslink density. A thorough look at the results also reveals that the property enhancement is obvious only at low silane loading (approximately 1.5 phr). Further increase of silane loading generally has little influence on properties of the vulcanizates. In the case of Si-264, excessive use of silane could impair certain properties such as modulus and hardness due to the plasticizing effect. Compared with Si-264, Si-69 imparts the rubber vulcanizates with poorer aging resistance. Explanation goes to the sulfur contribution effect of Si-69.

Research paper thumbnail of Dispersion Enhancement of Multi-Walled Carbon Nanotube (MWCNT) in Nitrile Rubber (NBR)

Advanced Materials Research, Oct 11, 2013

A study of reinforcement mechanism of multi-walled carbon nanotubes (MWCNT) in nitrile rubber (NB... more A study of reinforcement mechanism of multi-walled carbon nanotubes (MWCNT) in nitrile rubber (NBR) matrix was carried out. Attempts to enhance the dispersion degree of MWCNT and the NBR-MWCNT interaction were conducted using numerous approaches, namely, sonication and chemical treatments of MWCNT with nitric acid (HNO 3), nitric-sulfuric acid mixture (HNO 3 /H 2 SO 4) and potassium permanganate (KMnO 4). Rheological behavior, dynamic properties and electrical properties of MWCNT/NBR vulcanizates were monitored. Results gained reveal the magnitude of Payne effect increases with MWCNT content and mixing time. The expanded MWCNT and continuous-network formation are observed with an increase in mixing time, yielding enhanced mechanical properties and electrical properties. With MWCNT modification, a significant reduction in the state-of-mix of MWCNT composites is exhibited. SEM results demonstrate the highest magnitude of MWCNT dispersion in the system with HNO 3 , but relatively poor interaction with NBR. The HNO 3 /H 2 SO 4 or KMnO 4 system demonstrates poor MWCNT dispersion after treatment which is probably due to the compaction of MWCNT during the drying stage after the chemical treatment process, giving the detrimental effect to mechanical and electrical properties of vulcanizates.

Research paper thumbnail of A study to develop plastic magnets based on poly (vinyl chloride) and barium ferrite composites

Research paper thumbnail of Chitosan/xanthan gum porous scaffolds incorporated with in-situ-formed poly(lactic acid) particles: Their fabrication and ability to adsorb anionic compounds

Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2020

Research paper thumbnail of Physicoelectrical Properties and Piezoresistive Sensing of the Extrusion-Based Conductive Rubber Composites: Simultaneous Effects of the Extrusion Parameters

Rubber Chemistry and Technology, 2020

Flexible conductive rubber composites (CRCs) were prepared based on carbon black–filled oil-exten... more Flexible conductive rubber composites (CRCs) were prepared based on carbon black–filled oil-extended styrene–butadiene rubber soft matrix. Using a variety of screw designs, the simultaneous effects of the twin-screw extrusion parameters (i.e., kneading element, dispersing position, and screw speed) on the physicoelectrical properties of the CRCs were investigated statistically. The increased intenseness of the extrusion parameters significantly enhances the piezoresistive sensing via the improved filler dispersion, increased rubber–filler interaction, and weakened filler–filler networks. Nevertheless, the influence of the kneading elements on the properties of the CRCs significantly decreases with an increase in the intenseness of the dispersing position or the screw speed, referred to as a “negative interaction.” An extreme intenseness of the screw design causes the excellent piezoresistive sensing of the CRCs, but with undesirable mechanical strength. Because those properties need...

Research paper thumbnail of Cure retardation of peroxide-cured silica filled natural rubber influenced by organosilane

Polymer Engineering & Science, 2018

The influence of silane coupling agent on properties of silica-filled compounds under peroxide cu... more The influence of silane coupling agent on properties of silica-filled compounds under peroxide curing was investigated. bis (triethoxysilylpropyl) tetrasulfide (TESPT) was selected in this study and its content was varied from 0 to 12% w/w of silica. It is found that with increasing TESPT content, bound rubber content, tensile strength, elongation at break and tear strength are enhanced. By contrast, magnitude of Payne's effect, modulus at 100% elongation (M 100) and heat build-up are decreased. The changes of such properties are attributed to the reduction of crosslink density in conjunction with the improvements of both rubber-filler interaction and degree of filler dispersion with increasing TESPT content in the peroxide curing system.

Research paper thumbnail of Influences of Styrene Butadiene Rubber and Silica Types on Performance of Passenger Car Radial Tire Tread

Rubber Chemistry and Technology, 2017

ABSTRACTA performance comparison among three types of styrene butadiene rubber (SBR), that is, em... more ABSTRACTA performance comparison among three types of styrene butadiene rubber (SBR), that is, emulsion polymerized SBR (ESBR), solution polymerized SBR (SSBR), and functionalized solution polymerized SBR (F-SSBR), was of interest. Effect of silica type, that is, highly dispersible silica and conventional precipitated silica, was also investigated. It is found that SSBR demonstrates significantly better heat build-up, dynamic set, abrasion resistance, including wet grip (WG) with comparable fuel efficiency, as compared to ESBR. As expected, the best tire performance, that is, abrasion resistance, WG, and fuel efficiency, is found in F-SSBR vulcanizates, attributed mainly to the greatest improvement in magnitude of rubber–filler interaction and degree of filler dispersion. Results reveal that the reactive functional group, that is, propylaminedimethoxysilane, which is chemically anchored at chain ends of F-SSBR, plays a crucial role in tire performance. Unexpectedly, silica type does...

Research paper thumbnail of Reinforcement of Multiwalled Carbon Nanotube in Nitrile Rubber: In Comparison with Carbon Black, Conductive Carbon Black, and Precipitated Silica

Journal of Nanomaterials, 2016

The properties of nitrile rubber (NBR) reinforced by multiwalled carbon nanotube (MWCNT), conduct... more The properties of nitrile rubber (NBR) reinforced by multiwalled carbon nanotube (MWCNT), conductive carbon black (CCB), carbon black (CB), and precipitated silica (PSi) were investigated via viscoelastic behavior, bound rubber content, electrical properties, cross-link density, and mechanical properties. The filler content was varied from 0 to 15 phr. MWCNT shows the greatest magnitude of reinforcement considered in terms of tensile strength, modulus, hardness, and abrasion resistance followed by CCB, CB, and PSi. The MWCNT filled system also exhibits extremely high levels of filler network and trapped rubber even at relatively low loading (5 phr) leading to high electrical properties and poor dynamic mechanical properties. Although CCB possesses the highest specific surface area, it gives lower level of filler network than MWCNT and also gives the highest elongation at break among all fillers. Both CB and PSi show comparable degree of reinforcement which is considerably lower than...

Research paper thumbnail of Properties of poly(lactic acid)/cellulose nanofiber biocomposites: Effect of polymeric plasticizers

Materials Today: Proceedings

Research paper thumbnail of Rejuvenating the structure and rheological properties of silica nanocomposites based on natural rubber

Polymer

The antagonistic effect of processing and thermal annealing on both the filler structure and the ... more The antagonistic effect of processing and thermal annealing on both the filler structure and the polymer matrix is explored in polymer nanocomposites based on natural rubber with precipitated silica incorporated by coagulation from aqueous suspension followed by roll-milling. Their structure and linear and non-linear rheology have been studied, with a particular emphasis on the effect of high temperature thermal treatment and the number of milling passes. Small-angle X-ray scattering intensities show that the silica is organized in small, unbreakable aggregates containing ca. 50 primary nanoparticles, which are reorganized on a larger scale in filler networks percolating at the highest silica contents. As expected, the filler network structure is found to be sensitive to milling, more milling inducing rupture, as evidenced by the decreasing Payne effect. After thermal treatment, the nanocomposite structure is found to be rejuvenated, erasing the effect of the previous milling on the low-strain modulus. In parallel, the dynamics of the samples described by the rheology or the calorimetric glass-transition temperature remain unchanged, whereas the natural latex polymer network structure is modified by milling towards a more fluid-like rheology, and cannot be recovered.

Research paper thumbnail of Performance Comparison of Various Surface Modifying Agents on Properties of Silica-Filled Neoprene Rubber

Rubber Chemistry and Technology, 2016

Influence of the surface modifying agents (SMAs) polyethylene glycol (PEG), 3-aminopropyl trietho... more Influence of the surface modifying agents (SMAs) polyethylene glycol (PEG), 3-aminopropyl triethoxysilane (APTES), and bis-(3-triethoxysilylpropyl)tetrasulfide (TESPT) on properties of silica-filled chloroprene rubber (CR) was investigated. Results reveal that the presence of SMAs greatly improves mechanical and dynamic properties of the silica-filled CR because of the reduced filler–filler interaction and improved rubber–filler interaction as evidenced by the Payne effect and bound rubber content results, respectively. When compared at the same SMA dosage, TESPT gives the best overall vulcanizate properties. This effect is attributed to high coupling efficiency of TESPT and its ability to donate sulfur atoms during vulcanization, leading to the improved filler dispersion, rubber–filler interaction, and cross-link density. APTES gives high coupling efficiency, but because of the lack of sulfur atoms, its performance is slightly inferior to that of TESPT. In contrast, PEG can only re...

Research paper thumbnail of Influence of Carbon Black/Silica Hybrid Ratio on Properties of Passenger Car Tire Sidewall

Periodica Polytechnica Chemical Engineering

Influence of carbon black (CB)/precipitated silica (SiO2) hybrid ratio on properties of a passeng... more Influence of carbon black (CB)/precipitated silica (SiO2) hybrid ratio on properties of a passenger car tire (PCT) sidewall based on natural rubber (NR) and butadiene rubber (BR) blend was investigated. Rubbers filled with various hybrid filler ratios at a constant loading of 50 phr were prepared and tested. The filler reinforcement efficiency in association with crucial properties of the tire sidewall were of interest. Results show the enhanced rubber–filler interaction with increasing SiO2 fraction leading to the improvement in many vulcanizate properties including hardness, tensile strength, tear strength and fatigue resistance, at the expense of cure efficiency and hysteretic behaviors (i.e., reduced heat build-up resistance and increased dynamic set). The results also suggest the improvement in tire sidewall performance of the NR/BR vulcanizates reinforced with CB/SiO2 hybrid filler, compared to that of the CB-filled vulcanizate.

Research paper thumbnail of The influence of modified soybean oil as processing aids in tire application

Research paper thumbnail of Effects of Blend Ratio and SBR Type on Properties of Carbon Black-Filled and Silica-Filled SBR/BR Tire Tread Compounds

Advances in Materials Science and Engineering

This work aimed at investigating the effects of blend ratio between styrene butadiene rubber (SBR... more This work aimed at investigating the effects of blend ratio between styrene butadiene rubber (SBR) and butadiene rubber (BR) and SBR type (E-SBR and S-SBR) on properties of SBR/BR tire tread compounds. Influences of these parameters on properties of the tread compounds reinforced by 80 parts per hundred rubber (phr) of carbon black (CB) and silica were also compared. Results reveal that hardness, strengths, and wet grip efficiency were impaired whereas rolling resistance was improved with increasing BR proportion. Surprisingly, the presence of BR imparted poorer abrasion resistance in most systems, except for the CB-filled E-SBR system in which an enhanced abrasion resistance was observed. Obviously, S-SBR gave superior properties (tire performance) compared to E-SBR, particularly obvious in the silica-filled system. Compared with CB, silica gave comparable strengths, better wet grip efficiency, and lower rolling resistance. Carbon black, however, offered greater abrasion resistance...

Research paper thumbnail of Assessment of crosslink network and network defects of unfilled and filled ethylene-propylene-diene terpolymer using solid state nuclear magnetic relaxation spectroscopy

Journal of Applied Polymer Science

Research paper thumbnail of An efficient highly flexible strain sensor: Enhanced electrical conductivity, piezoresistivity and flexibility of a strongly piezoresistive composite based on conductive carbon black and an ionic liquid

Composites Part A: Applied Science and Manufacturing

Research paper thumbnail of Cure and scorch in the processing of ethylene-propylene-diene terpolymer (EPDM)

Journal of Applied Polymer Science

Research paper thumbnail of A Study of Carbon Black Distribution and Properties in BR/NBR Blends: Roles of Commercial Homogenizer and Slipping Agent

Polymer Plastics Technology and Engineering, 2001

Effects of commercial processing aids, Struktol NS60 (hydrocarbon resin) homogenizer and Struktol... more Effects of commercial processing aids, Struktol NS60 (hydrocarbon resin) homogenizer and Struktol WB16 (a mixture of metal salt and a fatty acid amide) slipping agent on the distribution of carbon black and physical properties in BR/NBR blends have been investigated. It was found that Struktol 60NS and Struktol WB16 in blend systems migrate preferentially to BR phase due to the strong interaction between Struktol and BR phase, leading to a decrease in viscosity of BR phase and thus an increase in carbon black residing in BR phase. Mechanical properties of unfilled compounds are strongly affected by blend ratio and loading of processing aids. However, in the case of filled compounds, the influence of carbon black distribution in each phase of the blends override those blend ratio and additive loading effects.

Research paper thumbnail of Effect of Compatibilizers on Rheology, Crosslink Density and Mechanical Properties of NR/NBR Blend

วารสารวิจัยและพัฒนา มจธ, 2007

Research paper thumbnail of Cure and dynamic mechanical properties in peroxide-cured isoprene rubber: effects of stearic acid and amine-based antioxidant

European Polymer Journal, Aug 1, 2004

Peroxide-cured isoprene rubber with various amounts of stearic acid and N-isopropyl-N 0-phenyl-p-... more Peroxide-cured isoprene rubber with various amounts of stearic acid and N-isopropyl-N 0-phenyl-p-phenylenediamine (i-PPD) was prepared. Processability, cure and dynamic mechanical properties of compounds were investigated. It has been found that stearic acid affects only the uncured compounds in terms of processability by acting as a lubricant, and plays no significant role in curing and dynamic mechanical properties. By contrast, i-PPD as an aminebased antioxidant shows pronounced effect on processability, cure and dynamic mechanical properties. The addition of i-PPD up to 2 phr could increase Mooney viscosity due to a thermal stabilization during high shear mixing. Exceeding this concentration, i-PPD shows plasticizing effect leading to a decrease in Mooney viscosity. Additionally, it has been shown that the addition of i-PPD reduces the crosslink density affecting remarkably the dynamic mechanical properties of compounds.

Research paper thumbnail of Roles of silane coupling agents on properties of silica-filled polychloroprene

European Polymer Journal, Mar 1, 2006

Silane coupling agent is used extensively to improve reinforcing efficiency of silica. Recently, ... more Silane coupling agent is used extensively to improve reinforcing efficiency of silica. Recently, many types of silane coupling agents have been developed and their roles on reinforcing improvement have been studied in many types of rubbers. In the present study, roles of the two widely used silane coupling agents, i.e., bis-(3-triethoxysilylpropyl) tetrasulfane (Si-69) and 3-thiocyanatopropyl triethoxy silane (Si-264) were studied in silica-filled polychloroprene (CR). The results reveal that the presence of Si-69 and Si-264 improves significantly the processability of the rubber compounds. The improvement is more pronounced for Si-264 due to its lower molecular weight and, thus, viscosity. Surprisingly, the results show that Si-69 and Si-264 affect cure characteristics differently, i.e., Si-69 somewhat retards cure while Si-264 accelerates cure. However, both Si-69 and Si-264 result in an increased crosslink density of the vulcanizates. The presence of silane coupling agent also enhances the mechanical properties of the vulcanizates due to the combined effects of better filler dispersion, better rubber-filler interaction and increased crosslink density. A thorough look at the results also reveals that the property enhancement is obvious only at low silane loading (approximately 1.5 phr). Further increase of silane loading generally has little influence on properties of the vulcanizates. In the case of Si-264, excessive use of silane could impair certain properties such as modulus and hardness due to the plasticizing effect. Compared with Si-264, Si-69 imparts the rubber vulcanizates with poorer aging resistance. Explanation goes to the sulfur contribution effect of Si-69.

Research paper thumbnail of Dispersion Enhancement of Multi-Walled Carbon Nanotube (MWCNT) in Nitrile Rubber (NBR)

Advanced Materials Research, Oct 11, 2013

A study of reinforcement mechanism of multi-walled carbon nanotubes (MWCNT) in nitrile rubber (NB... more A study of reinforcement mechanism of multi-walled carbon nanotubes (MWCNT) in nitrile rubber (NBR) matrix was carried out. Attempts to enhance the dispersion degree of MWCNT and the NBR-MWCNT interaction were conducted using numerous approaches, namely, sonication and chemical treatments of MWCNT with nitric acid (HNO 3), nitric-sulfuric acid mixture (HNO 3 /H 2 SO 4) and potassium permanganate (KMnO 4). Rheological behavior, dynamic properties and electrical properties of MWCNT/NBR vulcanizates were monitored. Results gained reveal the magnitude of Payne effect increases with MWCNT content and mixing time. The expanded MWCNT and continuous-network formation are observed with an increase in mixing time, yielding enhanced mechanical properties and electrical properties. With MWCNT modification, a significant reduction in the state-of-mix of MWCNT composites is exhibited. SEM results demonstrate the highest magnitude of MWCNT dispersion in the system with HNO 3 , but relatively poor interaction with NBR. The HNO 3 /H 2 SO 4 or KMnO 4 system demonstrates poor MWCNT dispersion after treatment which is probably due to the compaction of MWCNT during the drying stage after the chemical treatment process, giving the detrimental effect to mechanical and electrical properties of vulcanizates.