The Experts below are selected from a list of 285 Experts worldwide ranked by ideXlab platform
H. L. Frisch - One of the best experts on this subject based on the ideXlab platform.
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Sequential Interpenetrating Polymer Networks of Isotactic Polystyrene and Heterotactic Polystyrene
Macromolecules, 1996Co-Authors: H. L. FrischAbstract:The synthesis and characterization of sequential Interpenetrating Polymer Networks (SIPN's) of isotactic polystyrene and heterotactic polystyrene are reported in this paper. SIPN's with different cross-linking degrees or different compositions of isotactic PS Networks show single Tg's in DSC thermograms, while in SEM micrographs the SIPN's exhibit a heterogeneous phase morphology.
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Pseudo Interpenetrating Polymer Networks of Crystalline Polystyrene
Macromolecules, 1994Co-Authors: Y. Xue, Silvana C. Ngo, Jun Okuda, H. L. FrischAbstract:Pseudo Interpenetrating Polymer Networks (IPN's) of linear syndiotactic polystyrene (syn-PS) and cross-linked atactic polystyrene (c-PS) were prepared and characterized. The crystalline behavior of syn-PS in Polymer Networks and the morphology of pseudo-IPN's of syn-PS/c-PS have been studied by DSC and SEM. Pseudo-IPN's of linear isotactic polystyrene and c-PS as well as linear syn-PS and cross-linked atactic poly(methyl methacrylate) were also prepared for comparison with the pseudo-IPN's of syn-PS and c-PS
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Macromolecular topology. Metastable isomers from pseudo Interpenetrating Polymer Networks
New Journal of Chemistry, 1993Co-Authors: H. L. FrischAbstract:After briefly reviewing macromolecular topological isomers we point out the possibility of obtaining metastable, one phase materials from pseudo Interpenetrating Polymer Networks containing, modest concentrations, of very high molecular weight linear chains or star Polymers. We call these examples of metastable macromolecular topological isomers since they are more stable than the usual physical Polymer entanglements but very considerably less stable than «permanently» bonded knots, catenanes or Interpenetrating Polymer Networks. We list some properties of these materials which can also be considered as metastable Polymeric rotaxanes
L. A. Sorochinskaya - One of the best experts on this subject based on the ideXlab platform.
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Formation of linear Polymers in confined intranetwork space during synthesis of sequential semi-Interpenetrating Polymer Networks
Polymer Science Series B, 2009Co-Authors: L. A. Sorochinskaya, G. V. DudarenkoAbstract:Sequential semi-Interpenetrating Polymer Networks based on polyurethanes with different crosslink densities and linear polystyrene, poly(butyl methacrylate), and poly(methacrylic acid) have been studied. For the parent polyurethanes, the molecular mass of chain segments between crosslink junctions is estimated by the Flory-Rehner method. The kinetics of formation of linear Polymers in semi-Interpenetrating Polymer Networks is investigated as a function of the crosslink density of the polyurethane network. The molecular-mass distributions of linear Polymers developed in semi-Interpenetrating Polymer Networks are examined by size-exclusion chromatography. The relationship between the kinetics of formation of linear components under the conditions of confined space and their molecular mass is established.
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Sequential semi-Interpenetrating Polymer Networks based on polyurethane and polystyrene
Polymer Science Series A, 2008Co-Authors: Yu. P. Gomza, T. T. Alekseeva, Yu.s. Lipatov, V. V. Klepko, L. A. Sorochinskaya, S.d. Nesin, N. V. YarovayaAbstract:The formation of microheterogeneous sequential semi-Interpenetrating Polymer Networks based on network polyurethanes with different molecular masses of chain segments between crosslinks and a linear polystyrene has been studied by DSC and small-angle X-ray scattering. It has been shown that variation in the molecular mass of Polymer segments between polyurethane network junctions affects the formation of the linear component of semi-Interpenetrating Polymer Networks. As a result, the material structure may change in a wide range from a nearly single-phase system to a two-phase one. SAXS measurements indicate that there is a cymbate dependence between the degree of segregation of components of sequential semi-Interpenetrating Polymer Networks and their microheterogeneous structure on the internetwork space. Two hierarchical heterogeneity levels are found to exist in Polymer Networks, and the features of each of these levels are analyzed.
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Effect of spatial constraints on phase separation during Polymerization in sequential semi-Interpenetrating Polymer Networks
Polymer Science Series A, 2008Co-Authors: N. V. Babkina, L. A. Sorochinskaya, Yu. I. DatsyukAbstract:The viscoelastic properties of sequential semi-Interpenetrating Polymer Networks prepared via the swelling of network polyurethane in different monomers (butyl methacrylate, styrene) followed by their Polymerization in the polyurethane matrix have been studied by means of dynamic mechanical analysis. It is found that the relaxation behavior of the test systems and the degree of segregation of the components depends on Mc of the polyurethane matrix because of a change in the molecular mass of the Polymer block. The compatibility of the components in sequential semi-Interpenetrating Polymer Networks substantially increases when the network inner space in the polyurethane matrix decreases.
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Hybrid Materials Based on Sequential Semi-Interpenetrating Polymer Networks
Molecular Crystals and Liquid Crystals, 2008Co-Authors: T. T. Alekseeva, N. V. Yarovaya, N. V. Babkina, Yuri Lipatov, L. A. SorochinskayaAbstract:Peculiarities of formation kinetics of sequential semi-Interpenetrating Polymer Networks based on crosslinked polyurethane with different cross-linking density and linear polystyrene, polybutylmethacrylate have been studied. Viscoelastic and thermophysical properties of sequential semi-IPNs were investigated by the method of dynamic mechanical analysis and differential scanning calorimetry. The experimental data show the dependence of the kinetic parameters of Polymerization and relaxation properties on Mc.
Y. Xue - One of the best experts on this subject based on the ideXlab platform.
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Pseudo Interpenetrating Polymer Networks of Crystalline Polystyrene
Macromolecules, 1994Co-Authors: Y. Xue, Silvana C. Ngo, Jun Okuda, H. L. FrischAbstract:Pseudo Interpenetrating Polymer Networks (IPN's) of linear syndiotactic polystyrene (syn-PS) and cross-linked atactic polystyrene (c-PS) were prepared and characterized. The crystalline behavior of syn-PS in Polymer Networks and the morphology of pseudo-IPN's of syn-PS/c-PS have been studied by DSC and SEM. Pseudo-IPN's of linear isotactic polystyrene and c-PS as well as linear syn-PS and cross-linked atactic poly(methyl methacrylate) were also prepared for comparison with the pseudo-IPN's of syn-PS and c-PS
Siddaramaiah - One of the best experts on this subject based on the ideXlab platform.
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Synthesis and characterization of polyurethane/poly(vinylidene chloride) Interpenetrating Polymer Networks
Journal of Applied Polymer Science, 2007Co-Authors: Muneera Begum, Siddaramaiah, R. Somashekar, H SomashekarappaAbstract:A series of polyurethane (PU)/poly(vinylidene chloride) (PVDC) Interpenetrating Polymer Networks (IPNs) were synthesized through variations in the amounts of the prepolyurethane and vinylidene chloride monomer via sequential Polymerization (80/20, 60/40, 50/50, 40/60, 30/70, and 20/80 PU/PVDC). The physicomechanical and optical properties of the IPNs were investigated. Thermogravimetric analysis (TGA) studies of the IPNs were performed to establish their thermal stability. TGA thermograms showed that the thermal degradation of the IPNs proceeded in three steps. Microcrystalline parameters, such as the crystal size and lattice disorder, of the PU/PVDC IPNs were estimated with wide-angle X-ray scattering. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 1375–1381, 2007
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Interpenetrating Polymer Networks from castor oil-based polyurethane and polystyrene
Polymer Degradation and Stability, 1999Co-Authors: Siddaramaiah, P. Mallu, A VaradarajuluAbstract:Two component Interpenetrating Polymer Networks (IPNs) of castor oil based polyurethanes (PU) and polystyrene (PS) were prepared by sequential Polymerization. The liquid polyureathane were prepared by reacting hydroxyl groups of castor oil with methylene diisocyanate (MDI). These polyurethanes were swollen in polystyrene monomer and subsequently Polymerised by radical Polymerization initiated with benzoyl peroxide in the presence of the crosslinking agent divinyl benzene (DVB). A series of Interpenetrating Polymer Networks (PU/PS IPNs) were obtained as tough films by casting in glass moulds. The characteristics of these films were determined: resistance to chemical reagents, thermal behaviour (TGA), tensile strength, tensile modulus and elongation at break (%). The morphology was determined by scanning electron microscopy (SEM).
Bhikhu Suthar - One of the best experts on this subject based on the ideXlab platform.
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Interpenetrating Polymer Networks from castor oil-based polyurethanes and polystyrene, XXV
Polymer International, 1994Co-Authors: Bhikhu Suthar, Kanak Jadav, Mayank DaveAbstract:Interpenetrating Polymer Networks (IPNs) of castor oil-based polyurethanes and polystyrene were prepared by simultaneous Polymerization. The liquid prepolyurethanes were formed by reacting the hydroxyl functionality of castor oil with isophorone diisocyanate using different stoichiometric NCO/OH ratios. These prepolyurethanes were mixed with styrene monomer and subsequently Polymerized by free radical Polymerization initiated by benzoyl peroxide in the presence of the crosslinker 1,4-divinyl benzene. The Interpenetrating Polymer Networks. PU/PS IPNs, were obtained as tough and transparent films by the transfer moulding technique. These IPNs were characterized by the static mechanical properties (tensile strength, Young's modulus and % elongation), thermal properties and morphology. The dielectric relaxation properties (σ, E′, E″ and tanδ) of the IPNs at different temperatures were studied.
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Thermal stability of castor oil-based Interpenetrating Polymer Networks
Thermochimica Acta, 1993Co-Authors: Bhikhu Suthar, Mayank Dave, Kanak JadavAbstract:Abstract Two-component sequential-Interpenetrating Polymer Networks (IPNs) from castor oil-based polyurethanes and poly(methyl methacrylate) have been prepared. Component I-polyurethane was formed by reacting the hydroxyl functionality of castor oil with different diisocyanates in the stoichiometric NCO/OH ratio of 1.6. These polyurethanes were mixed individually with methyl methacrylate monomer and subsequently an Interpenetrating network prepared by free radical Polymerization initiated by benzoyl peroxide in the presence of crosslinking agent. The Interpenetrating Polymer Networks, PU/PMMA IPNs, were moulded into tough and transparent films. The thermal stability of these IPNs was assessed by thermogravimetric analysis.
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Interpenetrating Polymer Networks from Castor Oil Based Polyurethanes and Poly(Methyl Methacrylate) XX
International Journal of Polymeric Materials, 1991Co-Authors: Bhikhu Suthar, Nilesh Parikh, Nimish PatelAbstract:Abstract Two component Interpenetrating Polymer Networks (IPNs) of castor oil based polyurethanes and poly(methyl methacrylate) were prepared by sequential Polymerization. The liquid polyurethanes were formed by reacting the hydroxyl group of castor oil with diphenyl methane diisocyanate at different stoichiometric NCO/OH ratios. These polyurethanes were swollen in methyl methacrylate monomer and subsequently Polymerized by radical Polymerization initiated with benzoyl peroxide in presence of crosslinkers ethylene glycol dimethacrylate and 1,3-propanediamine. Novel Interpenetrating Polymer Networks PU/PMMA IPNs were obtained as films by transfer molding technique. These IPNs were characterized in terms of crosslink density and mechanical properties. The morphology was studied by transmission electron microscopy. Thermal stability was assessed from the thermogravimetric data.
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STUDY OF MECHANICAL PROPERTIES AND MORPHOLOGY OF Interpenetrating Polymer Networks FROM CASTOR OIL BASED POLYURETHANE AND POLYSTYRENE
Polymer International, 1991Co-Authors: Bhikhu Suthar, Nilesh Parikh, N. Z. PatelAbstract:Polyurethane-polystyrene sequential Interpenetrating Polymer Networks have been synthesized from castor oil, diphenylmethane diisocyanate, styrene, ethylene glycol dimethacrylate as a crosslinker and benzoyl peroxide as an activator. The Interpenetrating Polymer Networks were obtained as tough and transparent films by a transfer moulding technique. These IPNs were characterized by mechanical properties, viz. tensile strength, Young's modulus, elongation at break and Shore A hardness, and crosslink density. The morphological behaviour was studied by dynamic mechanical analysis and scanning electron microscopy.
