The Experts below are selected from a list of 231 Experts worldwide ranked by ideXlab platform

Henri Cramail - One of the best experts on this subject based on the ideXlab platform.

  • AB type polyaddition route to Thermoplastic polyurethanes from fatty acid derivatives
    Polymer Chemistry, 2012
    Co-Authors: Arvind S. More, Benoît Gadenne, Carine Alfos, Henri Cramail
    Abstract:

    Naturally occurring oleic acid and undecylenic acid derivatives were successfully utilized to synthesize a series of new semi-crystalline polyurethanes via the AB-type polycondensation approach. A set of four novel AB-type monomers was prepared via the use of environmentally benign thiol–ene chemistry. These AB-type monomers were self-polycondensed (with or without catalyst) in two ways: (a) the hydroxyl–acyl azide approach and (b) the melt transurethane method in order to obtain reasonably high molar mass polyurethanes. The resulting polymers were thoroughly characterized by NMR, SEC, DSC, TGA and MALDI-TOF mass spectroscopy. The MALDI-TOF analysis confirmed the formation of linear polyurethanes with a trace amount of macrocycles. All the polyurethanes exhibited fair thermal stability with no significant weight loss below 200 °C. The polyurethanes based on undecylenic acid as a monomer displayed a Thermoplastic Behavior with well-identified melting transitions. Further, DSC analysis revealed that polyurethanes prepared from undecylenic acid by different methods showed different glass and melting transitions. Two glass transition temperatures due to soft and hard segments were observed for polyurethanes synthesized from oleic acid derivatives, indicating a phase-separated morphology.

  • AB type polyaddition route to Thermoplastic polyurethanes from fatty acid derivatives
    Polymer Chemistry, 2012
    Co-Authors: Arvind S. More, Benoît Gadenne, Carine Alfos, Henri Cramail
    Abstract:

    Naturally occurring oleic acid and undecylenic acid derivatives were successfully utilized to synthesize a series of new semi-crystalline polyurethanes via the AB-type polycondensation approach. A set of four novel AB-type monomers was prepared via the use of environmentally benign thiol-ene chemistry. These AB-type monomers were self-polycondensed (with or without catalyst) in two ways: (a) the hydroxyl-acyl azide approach and (b) the melt transurethane method in order to obtain reasonably high molar mass polyurethanes. The resulting polymers were thoroughly characterized by NMR, SEC, DSC, TGA and MALDI-TOF mass spectroscopy. The MALDI-TOF analysis confirmed the formation of linear polyurethanes with a trace amount of macrocycles. All the polyurethanes exhibited fair thermal stability with no significant weight loss below 200 degrees C. The polyurethanes based on undecylenic acid as a monomer displayed a Thermoplastic Behavior with well-identified melting transitions. Further, DSC analysis revealed that polyurethanes prepared from undecylenic acid by different methods showed different glass and melting transitions. Two glass transition temperatures due to soft and hard segments were observed for polyurethanes synthesized from oleic acid derivatives, indicating a phase-separated morphology.

Angelo Petriccione - One of the best experts on this subject based on the ideXlab platform.

  • Toward a new Thermoplastic epoxy-based system
    2013
    Co-Authors: Angelo Petriccione
    Abstract:

    Thermoplastic composites allows attractive advantages over their thermosetting counterparts like a higher toughness, faster and more flexible manufacturing and intrinsic recyclability. Thermoplastic composite parts, nevertheless, are limited in size and thickness by traditional melt processing. As an alternative, reactive processing of textile fibre-reinforced Thermoplastics is a very attractive theme. Reactive processing systems stand as the next breakthrough of advanced composite development and materials research investigations due to their inherent synergy between Thermoplastic characteristic performance and thermosetting manufacturing processes, representing an high technological hybrid solution for many industrial sectors. The idea of produce epoxy-based reactive systems which exhibit a Thermoplastic Behavior is not far away, due to consolidated know-how on reactive processing of thermosetting epoxy resins. In this work, an epoxy-based system which can be reactively processed preserving the advantages of a Thermoplastic system was investigated and characterized. Applications in polymer/carbon nanotubes composites and fiber reinforced composites were analyzed and focused.

  • Toward a new Thermoplastic epoxy-based system: Nanocomposite and fibre reinforced material by reactive processing
    2013
    Co-Authors: Angelo Petriccione
    Abstract:

    Thermoplastic composites allows attractive advantages over their thermosetting counterparts like a higher toughness, faster and more flexible manufacturing and an intrinsic recyclability. Thermoplastic composite parts, nevertheless, are limited in size and thickness by traditional melt processing. As an alternative, reactive processing of textile fibre-reinforced Thermoplastics is a very attractive theme. Reactive processing systems stand as the next breakthrough of advanced composite development and materials research investigations due to their inherent synergy between Thermoplastic characteristic performance and thermosetting manufacturing processes, representing an high technological hybrid solution for many industrial sectors. The idea of produce an epoxy-based reactive system which exhibit a Thermoplastic Behavior is not far away, due to consolidated know-how on reactive processing of thermosetting epoxy resins. In this work, an epoxy-based system which can be reactively processed preserving the advantages of a Thermoplastic system was investigated and characterized. Applications in polymer/carbon nanotubes nanocomposites ad fiber reinforced composites were analyzed and focused.

Garth L Wilkes - One of the best experts on this subject based on the ideXlab platform.

  • synthesis and characterization of acrylonitrile methyl acrylate statistical copolymers as melt processable carbon fiber precursors
    Polymer, 2002
    Co-Authors: V A Bhanu, P Rangarajan, K Wiles, Michael J Bortner, M Sankarpandian, D Godshall, T E Glass, A K Banthia, Juan Yang, Garth L Wilkes
    Abstract:

    Abstract Statistical (random) copolymers of acrylonitrile (AN) and methyl acrylate (MA) have been synthesized by free radical homogeneous (solution) and heterogeneous (suspension) methods. Selected compositions can be fabricated by environment friendly, solvent-free melt spinning and are of interest as precursors for carbon fibers. The dynamic and steady state melt viscosities of these copolymers were studied as a function of molecular weight and copolymer composition. Melt processability at 200–220 °C depends on the copolymer composition, and also on the molecular weight, which was controlled by chain transfer agent concentration and reaction temperature. Copolymers of controlled molecular weight containing 10 or more mol[percnt] of methyl acrylate show good melt processability, which can be further enhanced by stabilizers. This Thermoplastic Behavior is supported by a significant increase in temperature by the cyclization exotherm. Thermal analysis (differential scanning calorimetry, dynamic mechanical analysis) further illustrates that the comonomers retarded the cyclization, which permits Thermoplastic processing.

Arvind S. More - One of the best experts on this subject based on the ideXlab platform.

  • AB type polyaddition route to Thermoplastic polyurethanes from fatty acid derivatives
    Polymer Chemistry, 2012
    Co-Authors: Arvind S. More, Benoît Gadenne, Carine Alfos, Henri Cramail
    Abstract:

    Naturally occurring oleic acid and undecylenic acid derivatives were successfully utilized to synthesize a series of new semi-crystalline polyurethanes via the AB-type polycondensation approach. A set of four novel AB-type monomers was prepared via the use of environmentally benign thiol–ene chemistry. These AB-type monomers were self-polycondensed (with or without catalyst) in two ways: (a) the hydroxyl–acyl azide approach and (b) the melt transurethane method in order to obtain reasonably high molar mass polyurethanes. The resulting polymers were thoroughly characterized by NMR, SEC, DSC, TGA and MALDI-TOF mass spectroscopy. The MALDI-TOF analysis confirmed the formation of linear polyurethanes with a trace amount of macrocycles. All the polyurethanes exhibited fair thermal stability with no significant weight loss below 200 °C. The polyurethanes based on undecylenic acid as a monomer displayed a Thermoplastic Behavior with well-identified melting transitions. Further, DSC analysis revealed that polyurethanes prepared from undecylenic acid by different methods showed different glass and melting transitions. Two glass transition temperatures due to soft and hard segments were observed for polyurethanes synthesized from oleic acid derivatives, indicating a phase-separated morphology.

  • AB type polyaddition route to Thermoplastic polyurethanes from fatty acid derivatives
    Polymer Chemistry, 2012
    Co-Authors: Arvind S. More, Benoît Gadenne, Carine Alfos, Henri Cramail
    Abstract:

    Naturally occurring oleic acid and undecylenic acid derivatives were successfully utilized to synthesize a series of new semi-crystalline polyurethanes via the AB-type polycondensation approach. A set of four novel AB-type monomers was prepared via the use of environmentally benign thiol-ene chemistry. These AB-type monomers were self-polycondensed (with or without catalyst) in two ways: (a) the hydroxyl-acyl azide approach and (b) the melt transurethane method in order to obtain reasonably high molar mass polyurethanes. The resulting polymers were thoroughly characterized by NMR, SEC, DSC, TGA and MALDI-TOF mass spectroscopy. The MALDI-TOF analysis confirmed the formation of linear polyurethanes with a trace amount of macrocycles. All the polyurethanes exhibited fair thermal stability with no significant weight loss below 200 degrees C. The polyurethanes based on undecylenic acid as a monomer displayed a Thermoplastic Behavior with well-identified melting transitions. Further, DSC analysis revealed that polyurethanes prepared from undecylenic acid by different methods showed different glass and melting transitions. Two glass transition temperatures due to soft and hard segments were observed for polyurethanes synthesized from oleic acid derivatives, indicating a phase-separated morphology.

Carine Alfos - One of the best experts on this subject based on the ideXlab platform.

  • AB type polyaddition route to Thermoplastic polyurethanes from fatty acid derivatives
    Polymer Chemistry, 2012
    Co-Authors: Arvind S. More, Benoît Gadenne, Carine Alfos, Henri Cramail
    Abstract:

    Naturally occurring oleic acid and undecylenic acid derivatives were successfully utilized to synthesize a series of new semi-crystalline polyurethanes via the AB-type polycondensation approach. A set of four novel AB-type monomers was prepared via the use of environmentally benign thiol–ene chemistry. These AB-type monomers were self-polycondensed (with or without catalyst) in two ways: (a) the hydroxyl–acyl azide approach and (b) the melt transurethane method in order to obtain reasonably high molar mass polyurethanes. The resulting polymers were thoroughly characterized by NMR, SEC, DSC, TGA and MALDI-TOF mass spectroscopy. The MALDI-TOF analysis confirmed the formation of linear polyurethanes with a trace amount of macrocycles. All the polyurethanes exhibited fair thermal stability with no significant weight loss below 200 °C. The polyurethanes based on undecylenic acid as a monomer displayed a Thermoplastic Behavior with well-identified melting transitions. Further, DSC analysis revealed that polyurethanes prepared from undecylenic acid by different methods showed different glass and melting transitions. Two glass transition temperatures due to soft and hard segments were observed for polyurethanes synthesized from oleic acid derivatives, indicating a phase-separated morphology.

  • AB type polyaddition route to Thermoplastic polyurethanes from fatty acid derivatives
    Polymer Chemistry, 2012
    Co-Authors: Arvind S. More, Benoît Gadenne, Carine Alfos, Henri Cramail
    Abstract:

    Naturally occurring oleic acid and undecylenic acid derivatives were successfully utilized to synthesize a series of new semi-crystalline polyurethanes via the AB-type polycondensation approach. A set of four novel AB-type monomers was prepared via the use of environmentally benign thiol-ene chemistry. These AB-type monomers were self-polycondensed (with or without catalyst) in two ways: (a) the hydroxyl-acyl azide approach and (b) the melt transurethane method in order to obtain reasonably high molar mass polyurethanes. The resulting polymers were thoroughly characterized by NMR, SEC, DSC, TGA and MALDI-TOF mass spectroscopy. The MALDI-TOF analysis confirmed the formation of linear polyurethanes with a trace amount of macrocycles. All the polyurethanes exhibited fair thermal stability with no significant weight loss below 200 degrees C. The polyurethanes based on undecylenic acid as a monomer displayed a Thermoplastic Behavior with well-identified melting transitions. Further, DSC analysis revealed that polyurethanes prepared from undecylenic acid by different methods showed different glass and melting transitions. Two glass transition temperatures due to soft and hard segments were observed for polyurethanes synthesized from oleic acid derivatives, indicating a phase-separated morphology.