Santanu Chattopadhyay - Academia.edu (original) (raw)

Papers by Santanu Chattopadhyay

Springer eBooks, 2013

ABSTRACT This chapter encompasses an overview of recent advances in the field of natural, synthet... more ABSTRACT This chapter encompasses an overview of recent advances in the field of natural, synthetic and semi-synthetic elastomer based bio-nanocomposites. Several naturally occurring polymers are considerably elastomeric and biocompatible. Elastin and its various derivatives are essential component of mammalian bio-systems. Various soft to semi-soft tissues of animals containing collagens, elastin proteins or other extra-cellular materials are classic examples of natural elastomeric bionanocomposites. There have been needs for developing synthetic or semi-synthetic elastomeric bio-nanocomposites for replacement or regeneration of such soft or semi-soft tissues or organs. Most of the elastomeric biopolymers lack in mechanical properties. Various modified cellulose components derived from plants like, cellulose whiskers, micro-fibrillated cellulose in their nano-scale size have proven promising in improving thermal, mechanical and moisture absorption properties of the elastomeric biopolymers. Similarly, biocompatible and bio-inert particulate nano filler systems including hydroxyapatite, bio-glass, silicates or other minerals can be potential reinforcing units for synthetic or semi-synthetic bionanocomposites. Non-toxicity of these precursors is utmost important for their actual bio-medical applications. Several synthetic methodologies have been adopted for the preparation of other novel and or bio-mimetic elastomeric bio-nanocomposites. Biodegradable polyurethanes and polycaprolactones, when modified with chitin or chitosan based chain extenders form novel nanocomposites, having wide applications in the area of biomaterials. Various precise and sophisticated characterization techniques namely, NMR, TEM, SEM, CD-spectroscopy have been routinely employed to evaluate the structure-property correlation of these novel bio-nanocomposites. Research is progress throughout the globe for further improvement in properties of such materials and subsequently to figure out novel practical applications of these elastomeric bio-nanocomposites.

Polymer Composites, Jan 5, 2013

ABSTRACT AbstractA novel carbon black (CB) and nanoclay (NC) dual phase‐filled system in SBR matr... more ABSTRACT AbstractA novel carbon black (CB) and nanoclay (NC) dual phase‐filled system in SBR matrix has been developed to be employed as a tyre tread compound with optimized performance properties. The nanocomposite has shown improved dynamic properties i.e. rolling resistance (tan δ at 60°C) and wet skid resistance (tan δ at 0°C), for relatively lower loading of NC (3 phr). However, the mechanical properties and wear resistance combined with above mentioned dynamic properties have been further improved by direct substitution of stearic acid with calcium stearate. This has been argued to be due to enhanced filler‐rubber interaction by the strong ionic interactions between the calcium ion (Ca++) and layered silicates (NC) having anionic surface. Transmission electron microscopy and low angle X‐ray diffraction studies have revealed the role of calcium stearate as a dispersion promoter for organoclay. Fourier transform infra‐red spectroscopy study has shown a shift in the SiOSi bond towards lower wave number indicating better polymer‐clay interaction. A detailed investigation on the dynamic rheological behavior of SBR‐CB‐NC nanocomposites has been carried out using rubber process analyzer to invoke an insight into the processing behavior of these composites. POLYM. COMPOS., 2013. © 2013 Society of Plastics Engineers

Journal of Materials Science and Engineering B, 2016

A novel carbon black (CB) and nanoclay (NC) filled system in Natural rubber (NR) matrix has been ... more A novel carbon black (CB) and nanoclay (NC) filled system in Natural rubber (NR) matrix has been developed for steel cord tyre ply compound with optimized performance properties. The effect of partial replacement of CB (N-220) by two different kinds of nanoclay (Cloisite-20A and Cloisite-30B) on the adhesion properties has been extensively investigated. The nanocomposites have shown improved adhesion properties between steel cord and rubber (aged and unaged) i.e. pull out force and rubber coverage (%), for relatively lower loading of both Cloisite 20A and Cloisite 30B (3 phr). The addition of nanoclay at lower loading (upto 3 phr) leads to an increase in the overall performance of the rubber compound. Due to nano filler reinforcement, the cohesive strength of the nanocomposites increases, but it is still lower than the adhesive force between steel cord and rubber. As a result the failure is mostly cohesive with higher pull out force. The adhesion improvement is more significant in case of 3phr Cloisite 30B. Cloisite 30B contains polar modified quaternary alkyl ammonium ions as intercalants in its gallery spacing, which may form hydrogen bonding with the resin network available near the copper sulphide bonding layer and leads to better rubber reinforcement and higher pull out force. Dynamic contact angle measurement, transmission electron microscopy (TEM) and low angle X-ray diffraction (XRD) studies have been carried out to explain these phenomena.

Journal of Materials Science and Engineering B, 2016

In the present work, a novel attempt has been proposed to simulate air permeability in tire inner... more In the present work, a novel attempt has been proposed to simulate air permeability in tire inner liner based on bromobutyl (BIIR)/epichlorohydrin (CO) rubber blend nanocomposite. ANSYS ® software has been adopted for FEM analysis. It provides an essential insight into the prediction of air permeability using thermal/gas analogy. The simulated results are compared and successfully validated with the field tire results. It is found that the hybrid nanocomposite offers a substantial reduction in air permeability as compared to the standard inner liner compound. It signifies the impact of the nanostructures on enhancing the gas barrier of the tire inner liner with time. The prediction gives a possibility to improve proactively the quality of inner liner compound developed.

Journal of Applied Polymer Science, 2003

... Mechanical and thermal properties of polyurethane elastomers based on hydroxyl-terminated pol... more ... Mechanical and thermal properties of polyurethane elastomers based on hydroxyl-terminated polybutadienes and biopitch. Renata Costa Silva Araújo,; Vânya Márcia Duarte Pasa. Article first published online: 12 FEB 2003. DOI: 10.1002/app.11526. ...

Journal of Research Updates in Polymer Science, 2015

In this article, we have mainly discussed about ferrite (Fe3O4) and its polymer based nanocomposi... more In this article, we have mainly discussed about ferrite (Fe3O4) and its polymer based nanocomposites. Ferrite particles have become an important research material because of their vast applications in the field of biotechnology, magnetic resonance imaging (MRI), and data storage. It has been observed that ferrite Fe3O4 particles show best performance for size less than 10-30 nm. This happens due to the super paramagnetic nature of such particles. In super paramagnetic range these particles exhibit zero remanence or coercivity. Therefore, various properties of ferrite (Fe3O4) nanoparticles and its polymer nanocomposites are very much dependent on the size, and distribution of the particles in the polymeric matrix. Moreover, it has been also observed that the shape of the nanocrystals plays important role in the determination of their fundamental properties. These particles show instability over longer times due to the formation of agglomerates generated by high surface energies. Therefore, protection strategies such as grafting and coatings with silica/carbon or polymers have been developed to stabilize them chemically. Recently, silylation technique is mainly used for the modification of nanoparticles. Experimentally, it has been observed that nanocomposites composed of polymer matrices and ferrite showed substantial improvements in stiffness, fracture toughness, sensing ability (magnetic as well as electric), impact energy absorption, and electro-catalytic activities to bio-species.

Nanoscale Research Letters, 2009

Use of sulfur crosslinked nanogels to improve various properties of virgin elastomers was investi... more Use of sulfur crosslinked nanogels to improve various properties of virgin elastomers was investigated for the first time. Natural rubber (NR) and styrene butadiene rubber (SBR) nanogels were prepared by prevulcanization of the respective rubber lattices. These nanogels were characterized by dynamic light scattering, atomic force microscopy (AFM), solvent swelling, mechanical, and dynamic mechanical property measurements. Intermixing of gel and matrix at various ratios was carried out. Addition of NR gels greatly improved the green strength of SBR, whereas presence of SBR nanogels induced greater thermal stability in NR. For example, addition of 16 phr of NR gel increased the maximum tensile stress value of neat SBR by more than 48%. Noticeable increase in glass transition temperature of the gel filled systems was also observed. Morphology of these gel filled elastomers was studied by a combination of energy dispersive X-ray mapping, transmission electron microscopy, and AFM techniques. Particulate filler composite reinforcement models were used to understand the reinforcement mechanism of these nanogels.

Journal of Biomedical Materials Research Part A, 2014

An injectable biodegradable hydrogel was prepared for temperature-responsive pulsatile release of... more An injectable biodegradable hydrogel was prepared for temperature-responsive pulsatile release of insulin. Triblock copolymer of poly(ethylene glycol)-poly(ε-caprolactone)-poly(ethylene glycol) (PEG-PCL-PEG, PECE) was prepared by ring opening bulk copolymerization and characterized using FT-IR, (1) HNMR, and gel permeation chromatography. Aqueous solution of PECE formed an injectable hydrogel, which was solution at room temperature and transformed into gel at 37°C. The temperature-responsive sol-gel transition and crystallinity of PECE hydrogel was studied and compared with pluronic, a well-studied nonbiodegradable injectable hydrogel. In vitro release study revealed that insulin release profile of PECE was similar to pluronic, and its viscosity was 1/30(th) of pluronic sol at 10,000 s(-1) shear rate. Release behavior of insulin from PECE hydrogels followed Fickian diffusion of first order. Insulin retained its secondary structure after release as confirmed by circular dichroism spectrum. A threefold increase in Fickian diffusion coefficient was evidenced when temperature was increased from 34 to 40°C because of crystalline melting of PCL part of PECE. Pulsatile release of insulin showed a correlation coefficient of 0.90 with the change of temperature.

Soft Matter, 2014

A new method is developed for preparation of amphiphilic block copolymer micellar nanoparticles a... more A new method is developed for preparation of amphiphilic block copolymer micellar nanoparticles and investigated as a delivery system for celecoxib, a hydrophobic model drug. Biodegradable block copolymers of poly(ethylene glycol) (PEG) and poly(ε-caprolactone) (PCL) were synthesized by ring opening copolymerization and characterized thoroughly using FTIR, (1)H NMR and GPC. The block copolymer was dispersed in distilled water at 60 °C and then it was chilled in an ice bath for the preparation of the micellar nanoparticles. Polymers self-assembled to form micellar nanoparticles (<50 nm) owing to their amphiphilic nature. The prepared micellar nanoparticles were analyzed using HR-TEM, DLS and DSC. The cytotoxicity of the polymer micellar nanoparticles was investigated against HaCaT cell lines. The study of celecoxib release from the micellar nanoparticles was carried out to assess their suitability as a drug delivery vehicle. Addition of the drug to the system at low temperature is an added advantage of this method compared to the other temperature assisted nanoparticle preparation techniques. In a nutshell, polymer micellar nanoparticles prepared using the heat-chill method are believed to be promising for the controlled drug release system of labile drugs, which degrade in toxic organic solvents and at higher temperatures.

Polymer Composites, 2013

ABSTRACT AbstractA novel carbon black (CB) and nanoclay (NC) dual phase‐filled system in SBR matr... more ABSTRACT AbstractA novel carbon black (CB) and nanoclay (NC) dual phase‐filled system in SBR matrix has been developed to be employed as a tyre tread compound with optimized performance properties. The nanocomposite has shown improved dynamic properties i.e. rolling resistance (tan δ at 60°C) and wet skid resistance (tan δ at 0°C), for relatively lower loading of NC (3 phr). However, the mechanical properties and wear resistance combined with above mentioned dynamic properties have been further improved by direct substitution of stearic acid with calcium stearate. This has been argued to be due to enhanced filler‐rubber interaction by the strong ionic interactions between the calcium ion (Ca++) and layered silicates (NC) having anionic surface. Transmission electron microscopy and low angle X‐ray diffraction studies have revealed the role of calcium stearate as a dispersion promoter for organoclay. Fourier transform infra‐red spectroscopy study has shown a shift in the SiOSi bond towards lower wave number indicating better polymer‐clay interaction. A detailed investigation on the dynamic rheological behavior of SBR‐CB‐NC nanocomposites has been carried out using rubber process analyzer to invoke an insight into the processing behavior of these composites. POLYM. COMPOS., 2013. © 2013 Society of Plastics Engineers

Journal of Polymer Research, 2011

Long-time stress relaxation behavior of virgin elastomers, chemically crosslinked nanogels and na... more Long-time stress relaxation behavior of virgin elastomers, chemically crosslinked nanogels and nanogel filled elastomers was studied with the help of a dynamic mechanical analyzer. Sulfur crosslinked natural rubber and styrene butadiene rubber nanogels and nanocomposite gels were prepared and characterized using different methods. These gels were added in to the virgin elastomer matrix at different concentrations. Presence of crosslinked gels

Advanced Structured Materials, 2013

ABSTRACT This chapter encompasses an overview of recent advances in the field of natural, synthet... more ABSTRACT This chapter encompasses an overview of recent advances in the field of natural, synthetic and semi-synthetic elastomer based bio-nanocomposites. Several naturally occurring polymers are considerably elastomeric and biocompatible. Elastin and its various derivatives are essential component of mammalian bio-systems. Various soft to semi-soft tissues of animals containing collagens, elastin proteins or other extra-cellular materials are classic examples of natural elastomeric bionanocomposites. There have been needs for developing synthetic or semi-synthetic elastomeric bio-nanocomposites for replacement or regeneration of such soft or semi-soft tissues or organs. Most of the elastomeric biopolymers lack in mechanical properties. Various modified cellulose components derived from plants like, cellulose whiskers, micro-fibrillated cellulose in their nano-scale size have proven promising in improving thermal, mechanical and moisture absorption properties of the elastomeric biopolymers. Similarly, biocompatible and bio-inert particulate nano filler systems including hydroxyapatite, bio-glass, silicates or other minerals can be potential reinforcing units for synthetic or semi-synthetic bionanocomposites. Non-toxicity of these precursors is utmost important for their actual bio-medical applications. Several synthetic methodologies have been adopted for the preparation of other novel and or bio-mimetic elastomeric bio-nanocomposites. Biodegradable polyurethanes and polycaprolactones, when modified with chitin or chitosan based chain extenders form novel nanocomposites, having wide applications in the area of biomaterials. Various precise and sophisticated characterization techniques namely, NMR, TEM, SEM, CD-spectroscopy have been routinely employed to evaluate the structure-property correlation of these novel bio-nanocomposites. Research is progress throughout the globe for further improvement in properties of such materials and subsequently to figure out novel practical applications of these elastomeric bio-nanocomposites.

Springer eBooks, 2013

ABSTRACT This chapter encompasses an overview of recent advances in the field of natural, synthet... more ABSTRACT This chapter encompasses an overview of recent advances in the field of natural, synthetic and semi-synthetic elastomer based bio-nanocomposites. Several naturally occurring polymers are considerably elastomeric and biocompatible. Elastin and its various derivatives are essential component of mammalian bio-systems. Various soft to semi-soft tissues of animals containing collagens, elastin proteins or other extra-cellular materials are classic examples of natural elastomeric bionanocomposites. There have been needs for developing synthetic or semi-synthetic elastomeric bio-nanocomposites for replacement or regeneration of such soft or semi-soft tissues or organs. Most of the elastomeric biopolymers lack in mechanical properties. Various modified cellulose components derived from plants like, cellulose whiskers, micro-fibrillated cellulose in their nano-scale size have proven promising in improving thermal, mechanical and moisture absorption properties of the elastomeric biopolymers. Similarly, biocompatible and bio-inert particulate nano filler systems including hydroxyapatite, bio-glass, silicates or other minerals can be potential reinforcing units for synthetic or semi-synthetic bionanocomposites. Non-toxicity of these precursors is utmost important for their actual bio-medical applications. Several synthetic methodologies have been adopted for the preparation of other novel and or bio-mimetic elastomeric bio-nanocomposites. Biodegradable polyurethanes and polycaprolactones, when modified with chitin or chitosan based chain extenders form novel nanocomposites, having wide applications in the area of biomaterials. Various precise and sophisticated characterization techniques namely, NMR, TEM, SEM, CD-spectroscopy have been routinely employed to evaluate the structure-property correlation of these novel bio-nanocomposites. Research is progress throughout the globe for further improvement in properties of such materials and subsequently to figure out novel practical applications of these elastomeric bio-nanocomposites.

Polymer Composites, Jan 5, 2013

ABSTRACT AbstractA novel carbon black (CB) and nanoclay (NC) dual phase‐filled system in SBR matr... more ABSTRACT AbstractA novel carbon black (CB) and nanoclay (NC) dual phase‐filled system in SBR matrix has been developed to be employed as a tyre tread compound with optimized performance properties. The nanocomposite has shown improved dynamic properties i.e. rolling resistance (tan δ at 60°C) and wet skid resistance (tan δ at 0°C), for relatively lower loading of NC (3 phr). However, the mechanical properties and wear resistance combined with above mentioned dynamic properties have been further improved by direct substitution of stearic acid with calcium stearate. This has been argued to be due to enhanced filler‐rubber interaction by the strong ionic interactions between the calcium ion (Ca++) and layered silicates (NC) having anionic surface. Transmission electron microscopy and low angle X‐ray diffraction studies have revealed the role of calcium stearate as a dispersion promoter for organoclay. Fourier transform infra‐red spectroscopy study has shown a shift in the SiOSi bond towards lower wave number indicating better polymer‐clay interaction. A detailed investigation on the dynamic rheological behavior of SBR‐CB‐NC nanocomposites has been carried out using rubber process analyzer to invoke an insight into the processing behavior of these composites. POLYM. COMPOS., 2013. © 2013 Society of Plastics Engineers

Journal of Materials Science and Engineering B, 2016

A novel carbon black (CB) and nanoclay (NC) filled system in Natural rubber (NR) matrix has been ... more A novel carbon black (CB) and nanoclay (NC) filled system in Natural rubber (NR) matrix has been developed for steel cord tyre ply compound with optimized performance properties. The effect of partial replacement of CB (N-220) by two different kinds of nanoclay (Cloisite-20A and Cloisite-30B) on the adhesion properties has been extensively investigated. The nanocomposites have shown improved adhesion properties between steel cord and rubber (aged and unaged) i.e. pull out force and rubber coverage (%), for relatively lower loading of both Cloisite 20A and Cloisite 30B (3 phr). The addition of nanoclay at lower loading (upto 3 phr) leads to an increase in the overall performance of the rubber compound. Due to nano filler reinforcement, the cohesive strength of the nanocomposites increases, but it is still lower than the adhesive force between steel cord and rubber. As a result the failure is mostly cohesive with higher pull out force. The adhesion improvement is more significant in case of 3phr Cloisite 30B. Cloisite 30B contains polar modified quaternary alkyl ammonium ions as intercalants in its gallery spacing, which may form hydrogen bonding with the resin network available near the copper sulphide bonding layer and leads to better rubber reinforcement and higher pull out force. Dynamic contact angle measurement, transmission electron microscopy (TEM) and low angle X-ray diffraction (XRD) studies have been carried out to explain these phenomena.

Journal of Materials Science and Engineering B, 2016

In the present work, a novel attempt has been proposed to simulate air permeability in tire inner... more In the present work, a novel attempt has been proposed to simulate air permeability in tire inner liner based on bromobutyl (BIIR)/epichlorohydrin (CO) rubber blend nanocomposite. ANSYS ® software has been adopted for FEM analysis. It provides an essential insight into the prediction of air permeability using thermal/gas analogy. The simulated results are compared and successfully validated with the field tire results. It is found that the hybrid nanocomposite offers a substantial reduction in air permeability as compared to the standard inner liner compound. It signifies the impact of the nanostructures on enhancing the gas barrier of the tire inner liner with time. The prediction gives a possibility to improve proactively the quality of inner liner compound developed.

Journal of Applied Polymer Science, 2003

... Mechanical and thermal properties of polyurethane elastomers based on hydroxyl-terminated pol... more ... Mechanical and thermal properties of polyurethane elastomers based on hydroxyl-terminated polybutadienes and biopitch. Renata Costa Silva Araújo,; Vânya Márcia Duarte Pasa. Article first published online: 12 FEB 2003. DOI: 10.1002/app.11526. ...

Journal of Research Updates in Polymer Science, 2015

In this article, we have mainly discussed about ferrite (Fe3O4) and its polymer based nanocomposi... more In this article, we have mainly discussed about ferrite (Fe3O4) and its polymer based nanocomposites. Ferrite particles have become an important research material because of their vast applications in the field of biotechnology, magnetic resonance imaging (MRI), and data storage. It has been observed that ferrite Fe3O4 particles show best performance for size less than 10-30 nm. This happens due to the super paramagnetic nature of such particles. In super paramagnetic range these particles exhibit zero remanence or coercivity. Therefore, various properties of ferrite (Fe3O4) nanoparticles and its polymer nanocomposites are very much dependent on the size, and distribution of the particles in the polymeric matrix. Moreover, it has been also observed that the shape of the nanocrystals plays important role in the determination of their fundamental properties. These particles show instability over longer times due to the formation of agglomerates generated by high surface energies. Therefore, protection strategies such as grafting and coatings with silica/carbon or polymers have been developed to stabilize them chemically. Recently, silylation technique is mainly used for the modification of nanoparticles. Experimentally, it has been observed that nanocomposites composed of polymer matrices and ferrite showed substantial improvements in stiffness, fracture toughness, sensing ability (magnetic as well as electric), impact energy absorption, and electro-catalytic activities to bio-species.

Nanoscale Research Letters, 2009

Use of sulfur crosslinked nanogels to improve various properties of virgin elastomers was investi... more Use of sulfur crosslinked nanogels to improve various properties of virgin elastomers was investigated for the first time. Natural rubber (NR) and styrene butadiene rubber (SBR) nanogels were prepared by prevulcanization of the respective rubber lattices. These nanogels were characterized by dynamic light scattering, atomic force microscopy (AFM), solvent swelling, mechanical, and dynamic mechanical property measurements. Intermixing of gel and matrix at various ratios was carried out. Addition of NR gels greatly improved the green strength of SBR, whereas presence of SBR nanogels induced greater thermal stability in NR. For example, addition of 16 phr of NR gel increased the maximum tensile stress value of neat SBR by more than 48%. Noticeable increase in glass transition temperature of the gel filled systems was also observed. Morphology of these gel filled elastomers was studied by a combination of energy dispersive X-ray mapping, transmission electron microscopy, and AFM techniques. Particulate filler composite reinforcement models were used to understand the reinforcement mechanism of these nanogels.

Journal of Biomedical Materials Research Part A, 2014

An injectable biodegradable hydrogel was prepared for temperature-responsive pulsatile release of... more An injectable biodegradable hydrogel was prepared for temperature-responsive pulsatile release of insulin. Triblock copolymer of poly(ethylene glycol)-poly(ε-caprolactone)-poly(ethylene glycol) (PEG-PCL-PEG, PECE) was prepared by ring opening bulk copolymerization and characterized using FT-IR, (1) HNMR, and gel permeation chromatography. Aqueous solution of PECE formed an injectable hydrogel, which was solution at room temperature and transformed into gel at 37°C. The temperature-responsive sol-gel transition and crystallinity of PECE hydrogel was studied and compared with pluronic, a well-studied nonbiodegradable injectable hydrogel. In vitro release study revealed that insulin release profile of PECE was similar to pluronic, and its viscosity was 1/30(th) of pluronic sol at 10,000 s(-1) shear rate. Release behavior of insulin from PECE hydrogels followed Fickian diffusion of first order. Insulin retained its secondary structure after release as confirmed by circular dichroism spectrum. A threefold increase in Fickian diffusion coefficient was evidenced when temperature was increased from 34 to 40°C because of crystalline melting of PCL part of PECE. Pulsatile release of insulin showed a correlation coefficient of 0.90 with the change of temperature.

Soft Matter, 2014

A new method is developed for preparation of amphiphilic block copolymer micellar nanoparticles a... more A new method is developed for preparation of amphiphilic block copolymer micellar nanoparticles and investigated as a delivery system for celecoxib, a hydrophobic model drug. Biodegradable block copolymers of poly(ethylene glycol) (PEG) and poly(ε-caprolactone) (PCL) were synthesized by ring opening copolymerization and characterized thoroughly using FTIR, (1)H NMR and GPC. The block copolymer was dispersed in distilled water at 60 °C and then it was chilled in an ice bath for the preparation of the micellar nanoparticles. Polymers self-assembled to form micellar nanoparticles (<50 nm) owing to their amphiphilic nature. The prepared micellar nanoparticles were analyzed using HR-TEM, DLS and DSC. The cytotoxicity of the polymer micellar nanoparticles was investigated against HaCaT cell lines. The study of celecoxib release from the micellar nanoparticles was carried out to assess their suitability as a drug delivery vehicle. Addition of the drug to the system at low temperature is an added advantage of this method compared to the other temperature assisted nanoparticle preparation techniques. In a nutshell, polymer micellar nanoparticles prepared using the heat-chill method are believed to be promising for the controlled drug release system of labile drugs, which degrade in toxic organic solvents and at higher temperatures.

Polymer Composites, 2013

ABSTRACT AbstractA novel carbon black (CB) and nanoclay (NC) dual phase‐filled system in SBR matr... more ABSTRACT AbstractA novel carbon black (CB) and nanoclay (NC) dual phase‐filled system in SBR matrix has been developed to be employed as a tyre tread compound with optimized performance properties. The nanocomposite has shown improved dynamic properties i.e. rolling resistance (tan δ at 60°C) and wet skid resistance (tan δ at 0°C), for relatively lower loading of NC (3 phr). However, the mechanical properties and wear resistance combined with above mentioned dynamic properties have been further improved by direct substitution of stearic acid with calcium stearate. This has been argued to be due to enhanced filler‐rubber interaction by the strong ionic interactions between the calcium ion (Ca++) and layered silicates (NC) having anionic surface. Transmission electron microscopy and low angle X‐ray diffraction studies have revealed the role of calcium stearate as a dispersion promoter for organoclay. Fourier transform infra‐red spectroscopy study has shown a shift in the SiOSi bond towards lower wave number indicating better polymer‐clay interaction. A detailed investigation on the dynamic rheological behavior of SBR‐CB‐NC nanocomposites has been carried out using rubber process analyzer to invoke an insight into the processing behavior of these composites. POLYM. COMPOS., 2013. © 2013 Society of Plastics Engineers

Journal of Polymer Research, 2011

Long-time stress relaxation behavior of virgin elastomers, chemically crosslinked nanogels and na... more Long-time stress relaxation behavior of virgin elastomers, chemically crosslinked nanogels and nanogel filled elastomers was studied with the help of a dynamic mechanical analyzer. Sulfur crosslinked natural rubber and styrene butadiene rubber nanogels and nanocomposite gels were prepared and characterized using different methods. These gels were added in to the virgin elastomer matrix at different concentrations. Presence of crosslinked gels

Advanced Structured Materials, 2013

ABSTRACT This chapter encompasses an overview of recent advances in the field of natural, synthet... more ABSTRACT This chapter encompasses an overview of recent advances in the field of natural, synthetic and semi-synthetic elastomer based bio-nanocomposites. Several naturally occurring polymers are considerably elastomeric and biocompatible. Elastin and its various derivatives are essential component of mammalian bio-systems. Various soft to semi-soft tissues of animals containing collagens, elastin proteins or other extra-cellular materials are classic examples of natural elastomeric bionanocomposites. There have been needs for developing synthetic or semi-synthetic elastomeric bio-nanocomposites for replacement or regeneration of such soft or semi-soft tissues or organs. Most of the elastomeric biopolymers lack in mechanical properties. Various modified cellulose components derived from plants like, cellulose whiskers, micro-fibrillated cellulose in their nano-scale size have proven promising in improving thermal, mechanical and moisture absorption properties of the elastomeric biopolymers. Similarly, biocompatible and bio-inert particulate nano filler systems including hydroxyapatite, bio-glass, silicates or other minerals can be potential reinforcing units for synthetic or semi-synthetic bionanocomposites. Non-toxicity of these precursors is utmost important for their actual bio-medical applications. Several synthetic methodologies have been adopted for the preparation of other novel and or bio-mimetic elastomeric bio-nanocomposites. Biodegradable polyurethanes and polycaprolactones, when modified with chitin or chitosan based chain extenders form novel nanocomposites, having wide applications in the area of biomaterials. Various precise and sophisticated characterization techniques namely, NMR, TEM, SEM, CD-spectroscopy have been routinely employed to evaluate the structure-property correlation of these novel bio-nanocomposites. Research is progress throughout the globe for further improvement in properties of such materials and subsequently to figure out novel practical applications of these elastomeric bio-nanocomposites.