Investigations on the addition of styrene butadiene rubber in natural rubber and dichlorocarbene modified styrene butadiene rubber blends
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.
Abstract: This 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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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.
25 citations
TL;DR: The use of vegetable-oil-based polymeric plasticizers with nanotechnology can create new applications for plasticized poly(vinyl chloride) (PVC), as studied by TGA as discussed by the authors.
Abstract: The use of vegetable-oil-based polymeric plasticizers with nanotechnology can create new applications for plasticized poly(vinyl chloride) (PVC). Epoxidized Mesua ferrea L. (Ceylon Ironwood) seed oil was used as a plasticizer for PVC. Further, nanocomposites were prepared through an ex-situ technique using epoxidized-oil-swelled organically modified montmorillonite (5 wt%) and PVC. Notable improvement in thermal and processing characteristics of the nanocomposites was observed over those of the virgin polymer (in both unplasticized and plasticized PVC), as studied by TGA. The prepared nanocomposites were characterized by FTIR, SEM, TEM, and XRD techniques. A dramatic decrease in viscosity (7-fold) was observed in THF for a 10% solution of epoxidized-oil-modified PVC compared to unplasticized PVC in THF, as measured by Brookfield viscometer. Isothermal analysis at three different temperatures (100, 150, and 200°C) reveals sufficient stability of the epoxidized oil modified PVC nanocomposites, as confirmed by gravimetric and FTIR analysis. Augmentation of thermostability and good retention of mechanical properties of the (Mesua ferrea L.)-plasticized-PVC/clay nanocomposites with respect to rigid PVC vouch for the utility of the former as advanced industrial materials. J. VINYL ADDIT. TECHNOL., 18:168–177, 2012. © 2012 Society of Plastics Engineers
15 citations
TL;DR: In this paper, mixed antioxidants composed of antioxidant IPPD and novel rare earth lanthanum complex were used as an additive to prepare natural rubber (NR) samples, and the variations of macro-properties, surface characterizations, and internal groups were investigated by mechanical testing, X-ray photoelectron spectroscopy, and thermogravimetric analysis coupled with Fourier transform infrared spectroscope (TGA/FT-IR), respectively, to study the thermal-oxidative stability of NR.
Abstract: Mixed antioxidants composed of antioxidant IPPD and novel rare earth lanthanum complex were used as an additive to prepare natural rubber (NR) samples. The variations of macro-properties, surface characterizations, and internal groups were investigated by mechanical testing, X-ray photoelectron spectroscopy, and thermogravimetric analysis coupled with Fourier transform infrared spectroscopy (TGA/FT-IR), respectively, to study the thermal-oxidative stability of NR. The thermal-oxidative degradation kinetic parameters were determined by analyzing the thermogravimetric curves at different heating rates with two model-free methods, Kissinger method and Flynn–Wall–Ozawa method. The results all showed that, compared with pure antioxidant IPPD, the same mass of mixed antioxidants could indeed improve the thermal-oxidative stability of NR. Furthermore, based on the TGA/FT-IR results and quantum mechanics simulations, the autocatalytic, free radical chain reaction mechanism for the thermal-oxidative aging of NR was clarified, and the different function mechanisms of antioxidants IPPD and p-ASALa were also discussed. Except for functioning as a labile-hydrogen donor which is similar to antioxidant IPPD in protecting NR against autoxidation, p-ASALa has strong coordination abilities and large coordination numbers, resulting in the high efficiency in enhancing the thermal-oxidative stability of NR.
14 citations
Cites background from "Investigations on the addition of s..."
...However, the high content unsaturated isolated double bonds which are easily attacked by oxygen, especially under thermal condition, will lead to the deterioration in mechanical properties and thermal resistance of NR [1, 2]....
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8 citations
TL;DR: In this article, the results of rheometric tests showed that with adding dichlorocarbene-modified SBR compatibilizer and increasing OMMT, the optimum curing time and scorch time decreased.
Abstract: Rubber nanocomposites based on carboxylated acrylonitrile butadiene rubber and carboxylated styrene butadiene rubber (XNBR/XSBR) with different compositions (100/0, 80/20, 60/40, 40/60, 20/80 and 0/100) and various montmorillonite (OMMT) contents with compatibilizer dichlorocarbene-modified SBR (DCSBR) were prepared. The results of rheometric tests showed that with adding DCSBR compatibilizer and increasing OMMT, the optimum curing time and scorch time decreased. The X-ray diffraction analysis indicated adding DCSBR compatibilizer causes increase in distance between the layers of silicate plates in the rubber phase of nanocomposites compared to OMMT powder. This phenomenon was also confirmed by direct observation of the microstructure by a transmitted electron microscope. The addition of OMMT and DCSBR compatibilizer surprisingly increased the mechanical properties such as elongation at break, tensile modulus, tensile strength and fatigue strength of the XNBR/XSBR (80/20).
5 citations
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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.
1,084 citations
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
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
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.
150 citations
TL;DR: The viscoelastic properties of various crosslinked natural rubbers, NR, were investigated by mechanical spectroscopy as mentioned in this paper, and the glass transition temperature, Tg, was found to be dependent on both the crosslink density and crosslink type.
Abstract: The viscoelastic properties of various crosslinked natural rubbers, NR, were investigated by mechanical spectroscopy. The glass transition temperature, Tg, was found to be dependent on both the crosslink density and the crosslink type. Higher values of Tg were obtained for sulfur-crosslinked NR than for peroxide-crosslinked NR at the same crosslink density. The greater influence of the sulfur content on Tg may be attributed to polysulfidic crosslinks and cyclic sulfide structures favored at high sulfur contents. Sulfur-vulcanized NRs with monosulfidic crosslinks, favored at relatively high accelerator/sulfur ratios, have properties more similar to the peroxide-cured NR with simple carbon(SINGLE BOND)carbon crosslinks covalent bonds, resulting in only small shifts in Tg. A qualitative analysis of monosulfidic crosslinks and polysulfidic structures was performed with 13C solid-state NMR spectroscopy. The storage modulus, E′, in the rubbery plateau region increased with increasing crosslink density. However, the crosslink type did not influence the moduli values as much as it influenced the Tg values. Different methods of detecting the crosslink density were also discussed. © 1996 John Wiley & Sons, Inc.
103 citations