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Journal ArticleDOI

Investigations on the addition of styrene butadiene rubber in natural rubber and dichlorocarbene modified styrene butadiene rubber blends

01 Jan 2002-Journal of Materials Science (Kluwer Academic Publishers)-Vol. 37, Iss: 1, pp 109-116

TL;DR: In this paper, the use of styrene butadiene rubber (SBR) as a viscosity modifier in novel blends of natural rubber (NR) and dichlorocarbene modified SBR (DCSBR) was examined in order to analyse the influence of SBR in the blends.

AbstractThis paper focuses on the use of styrene butadiene rubber (SBR) as a viscosity modifier in novel blends of natural rubber (NR) and dichlorocarbene modified styrene butadiene rubber (DCSBR) The processing characteristics, vulcanisation kinetics, stress-strain behaviour, mechanical properties and low temperature transition of the blends have been examined in order to analyse the influence of SBR in the blends The change in cross-link density values from stress strain behaviour and equilibrium swelling data has been correlated with the technological properties of the blends The excellent mechanical properties and the increased cross-link density in blends in the presence of 5—10 phr of styrene butadiene rubber reveals the viscosity modifying action of SBR in NR/DCSBR blends The variation in viscosities of these blends with the addition of SBR is reflected in the DSC thermograms The resulting blends show very high resistance to thermal ageing as compared to those without SBR

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Citations
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Journal ArticleDOI
TL;DR: In this article, the effect of organically modified montmorillonite (org-MMT) on the thermal and flame retardant as well as hardness and mechanical properties of the nanocomposites based on the natural rubber (NR).
Abstract: Polymer/clay nanocomposites have some unique properties due to combination of flame resistance and improved mechanical and thermal stability properties which are important to enhance the material quality and performance. The objective of this work was to investigate the effect of organically modified montmorillonite (org-MMT) on the thermal and flame retardant as well as hardness and mechanical properties of the nanocomposites based on the natural rubber (NR). It was shown that by the addition of 3 wt % of org-MMT to NR, its aging hardness rise was decreased more than 55% and the ignition time was delayed about 150%. The reduction in heat release rate peak value was equal to 54% compared to the pristine NR. Addition of org-MMT improved the thermal stability of the NR. Furthermore, nanocomposites which were calendared before curing showed much more thermal stability and fire resistance than those which contained similar amount of organoclay. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011

40 citations

Journal ArticleDOI
TL;DR: In this article, Dicumyl peroxide was selected as a cross-linking agent and the solvent-resistance properties of these vulcanized natural rubber (NR)/chitosan (CS) blends were investigated by the equilibrium swelling method using benzene as solvent.
Abstract: This article discusses properties such as surface hardness, solvent uptake, cross-link density, diffusion coefficient, and tensile properties of vulcanized natural rubber (NR)/chitosan (CS) blends. Dicumyl peroxide was selected as a cross-linking agent. In the case of tensile properties, peroxide vulcanized blends show higher tensile strength and hardness (Shore A) than the unvulcanized blend. The effect of thermal aging on mechanical properties of vulcanized NR/CS blends was also examined. The solvent-resistance properties of these vulcanized blends were investigated by the equilibrium swelling method using benzene as solvent. The impact of weight fraction of chitosan on the transport properties of vulcanized blend was also analyzed. The improved solvent resistance for peroxide vulcanized blends proved the formation of cross-links in the rubber phase. The blends showed reduced swelling rate due to the tortuosity of the path and the reduced transport area in blended samples.

37 citations


Cites methods from "Investigations on the addition of s..."

  • ...The diffusion coefficient of benzene in the vulcanized blend has been computed by using Equation (2)....

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Journal ArticleDOI
TL;DR: In this paper, Nitrile rubber (NBR) based nanocomposite consisting of different concentrations of hydroxyapatite nanoparticles (HA) were prepared and characterized by FTIR, UV and X-ray diffraction studies.
Abstract: Nitrile rubber (NBR) based nanocomposite consists of different concentrations of hydroxyapatite nanoparticles (HA) were prepared and characterized by FTIR, UV and X-ray diffraction studies. The surface morphology of the nanocomposites were analyzed using SEM and optical microscopy. The glass transition temperature and thermal stability of NBR and its nanocomposites were done by DSC and TGA respectively. The electrical properties such as AC conductivity, dielectric constant and dielectric loss tangent were investigated in the frequency range of 102–106 Hz at room temperature. The FTIR spectra confirmed the interfacial interaction between NBR and the HA nanoparticles. The shift in the UV peak with broadness of composite indicates the formation of nanoparticles within the macromolecular chain of NBR. XRD pattern ascertained the ordered arrangement of nanoparticles with a decrease in the amorphous nature of parent polymer. Both the glass transition temperature and the thermal stability of the nanocomposites were higher than pure NBR and the glass transition temperature improved with the increase in concentration of nanoparticles in NBR composite indicating the strong interfacial adhesion between the polymer and nanoparticles. From DSC studies, thermodynamic parameters such as enthalpy and entropy change of the composites were also evaluated. AC conductivity of the nanocomposite was much greater than NBR and the magnitude of conductivity enhanced with the addition of nanoparticles. The observed enhancement in dielectric constant and dielectric loss tangent of composite with the increase in concentration of nanoparticle was attributed to the increase in number of interfacial interaction between the polymer and the nanoparticles.

22 citations

Journal ArticleDOI
TL;DR: In this article, a poly(2-ethyl-2-oxazoline) is blended with polyvinylpyrrolidone (PVP) to improve the optical and electrical properties of the material.
Abstract: Poly(2-ethyl-2-oxazoline) [PEOX] is blended with polyvinylpyrrolidone [PVP] having a relatively high dielectric constant to improve the optical and electrical properties of the material. PEOX-PVP polymer blends with 0, 20, 40, 60, and 80 wt% PVP are characterized by their structural, optical, electrical and dielectric properties. SEM images and XRD spectra show that PEOX and PVP have a good miscibility and compatibility. XRD also confirms the amorphous structure of the samples. FTIR spectra indicate the presence of hydrogen bonding between PEOX and PVP. The optical energy band gap, Egopt, and the width of the band tail of localized states in the forbidden band gap, ΔE, as determined by UV–Vis spectroscopy, are changing with PVP content. Electrical and dielectric properties are measured at frequencies from 10 Hz to 8 MHz using LCR meter. The dielectric constant, the dielectric loss, and the loss tangent (tanδ) decrease, whereas the AC conductivity increases with increasing frequency. PEOX:PVP (80:20 wt%) is an optimum blend with superior properties as compared with pure PEOX. This flexible and high-dielectric-constant polymer blend may have potential application in energy storage.

20 citations


References
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Book
01 Jan 1936
TL;DR: Hildebrand's book is an exception as mentioned in this paper, since the reviewer has taken the opportunity to renew his acquaintance with the earlier as well as the later text, and has found this to be a most interesting experience, since the book is full of matter which is not dealt with adequately in the ordinary text-books of physical chemistry.
Abstract: AbstractIT is not often that a reviewer, who has read through the first edition of a book, finds it worth while to do more than glance through a second edition, in order to discover and review the new sections that have been introduced. Prof. Hildebrand's book is an exception, since the reviewer has taken the opportunity to renew his acquaintance with the earlier as well as the later text, and has found this to be a most interesting experience, since the book is full of matter which is not dealt with adequately (and indeed appears to have been largely overlooked) in the ordinary text-books of physical chemistry.Solubility of Non-Electrolytes By Prof. Joel H. Hildebrand. (American Chemical Society Monograph Series, No. 17.) Second edition. Pp. 203. (New York: Reinhold Publishing Corporation; London: Chapman and Hall, Ltd., 1936.) 22s. 6d. net.

1,076 citations

Journal ArticleDOI
TL;DR: In this article, the observed morphology of the melt-blended polyethylene/polystyrene pair unambiguously supports the interfacial activity of poly(hydrogenated butadiene-b-styrene) copolymers.
Abstract: As investigated by optical and electron microscopy, the observed morphology of the meltblended polyethylene/polystyrene pair unambiguously supports the interfacial activity of poly(hydrogenated butadiene-b-styrene) copolymers. The phase size is significantly reduced, the interfacial adhesion is dramatically increased and the phase dispersion is firmly stabilized against coalescence during subsequent processing. Diblock copolymers with a balanced composition are the most efficient interfacial agents in such an extent that only small amounts (1–2 wt.-%) are required to obtain homogeneous and stable phase dispersions. The emulsification concept applied to melt-blended immiscible polymers appears to be a powerful technique to prepare valuable polymer alloys.

167 citations

Journal ArticleDOI
TL;DR: A survey of the results of the most important of these experimental studies, particularly in regard to the effect of experimental variables on 2C1 and 2C2 can be found in this paper.
Abstract: There has been a very large number of experimental studies of the elastic properties of amorphous polymer networks in uniaxial deformation, particularly elongation, over the past few decades. In spite of these efforts, and related theoretical investigations, major questions remain unanswered with regard to stress-strain isotherms over the range of moderate deformations. The major question in this area is the molecular basis or interpretation of the phenomenological constants 2C1 and 2C2 used to represent the experimentally observed isotherms. It is hoped that the present survey of the results of the most important of these experimental studies, particularly in regard to the effect of experimental variables on 2C1 and 2C2 will encourage additional work, leading to an unambiguous solution to this important unsolved problem in the area of rubberlike elasticity.

151 citations

BookDOI
01 Jan 1985
TL;DR: In this paper, the authors present a number of techniques for studying polymer blends, including pulsed-induction critical scattering (PICF) and X-ray scattering (X-Ray Scattering).
Abstract: 1. Thermodynamic Theory and Experimental Techniques for Polymer Blends.- 2. Glass Transitions and Compatibility Phase Behavior in Copolymer Containing Blends.- 3. Microscopy and other Methods of Studying Blends.- 4. Preparation of Blends.- 5. Light, Neutron and X-Ray Scattering Techniques for Studying Polymer Blends.- 6. Liquid-Liquid Phase Equilibria in Polymer Blends.- 7. Polymer Blend Modification of PVC.- 8. Synthesis of Block and Graft Copolymers.- 9. Block Copolymers Morphological and Physical Properties.- 10. Colloidal Behaviour and Surface Activity of Block Copolymers.- 11. Relationships between Morphology, Structure, Composition and Properties in Isotactic Polypropylene Based Blends.- 12. Rubber-Rubber Blends.- 13. Pure and Applied Research on Interpenetrating Polymer Networks and Related Materials.- 14. Fracture Toughness Evaluation of Blends and Mixtures and the Use of the J Method.- 15. Crazing and Cracking in Glassy Homopolymers.- 16. The Mechanical Properties of Homogeneous Glassy Polymer Blends.- 17. Mechanical Properties of High-Impact Polymers.- 18. Fatigue of High-Impact Polymers.- 19. Yielding and Failure Criteria for Rubber Modified Polymers, Part 1.- 20. Yielding and Failure Criteria for Rubber Modified Polymers, Part 2.- 21. Multiphase Thermosetting Polymers.- 22. Processing and Phase Morphology of Incompatible Polymer Blends.- Seminars.- 1. Pulse-Induced Critical Scattering.- 2. Phase Separation in Polymer Blends.- 3. Thermodynamics of Compatibility in Binary Polymeric Mixtures.- 4. PVC Blending Resins: Properties and Appllications.- 5. Block Copolymers as Homogenizing Agents in Blends of Amorphous and Semicrystalline Polymers.- 6. Study of Copolymer-Homopolymer Blends.- 7. Rubber-Plastics Blends.- 8. Isotactic Polypropylene/Rubber Blends: Effect of Crystallization Conditions and Composition on Properties.- 9. Ethylene-Propylene Rubber and Polyolefin Polymer Blends: Present Situation and Future Trends.

149 citations

Journal ArticleDOI
TL;DR: In this paper, a modification d'un copolymere butadiene hydrogene-styrene par insertion d'une courte sequence centrale isoprene, permettant de localiser le copolyme a l'interface du melange fondu d'homopolymeres
Abstract: Modification d'un copolymere butadiene hydrogene-styrene par insertion d'une courte sequence centrale isoprene, permettant de localiser le copolymere a l'interface du melange fondu d'homopolymeres

101 citations