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R D K Misra - One of the best experts on this subject based on the ideXlab platform.

  • The determining role of clay particles on mechanically induced surface damage and associated stress whitening in Polybutene–clay nanocomposites
    Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2004
    Co-Authors: R D K Misra, H Nathani, Aravind Dasari, S D Wanjale
    Abstract:

    Abstract The potential of atomic force microscopy to quantify the surface topography is combined with the surface features obtained by electron microscopy to examine susceptibility to mechanically induced surface damage in neat Polybutene and Polybutene–clay nanocomposites. The scratch tracks in Polybutene are characterized by ‘fish-scale psiloma’ morphology indicative of compressive plastic deformation and quasi-periodic cracking. While in Polybutene–clay nanocomposites, ‘ironing’, which is a less severe surface damage mechanism was dominant. Also, Polybutene–clay nanocomposites experience significantly reduced stress whitening, and is characterized by lower gray level in the plastically deformed surface damage region. This behavior is attributed to the effective reinforcement by clay particles that act in concert increasing the tensile modulus of the composite and restricts plastic deformation of the polymer matrix.

  • the determining role of clay particles on mechanically induced surface damage and associated stress whitening in Polybutene clay nanocomposites
    Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2004
    Co-Authors: R D K Misra, H Nathani, Aravind Dasari, S D Wanjale
    Abstract:

    Abstract The potential of atomic force microscopy to quantify the surface topography is combined with the surface features obtained by electron microscopy to examine susceptibility to mechanically induced surface damage in neat Polybutene and Polybutene–clay nanocomposites. The scratch tracks in Polybutene are characterized by ‘fish-scale psiloma’ morphology indicative of compressive plastic deformation and quasi-periodic cracking. While in Polybutene–clay nanocomposites, ‘ironing’, which is a less severe surface damage mechanism was dominant. Also, Polybutene–clay nanocomposites experience significantly reduced stress whitening, and is characterized by lower gray level in the plastically deformed surface damage region. This behavior is attributed to the effective reinforcement by clay particles that act in concert increasing the tensile modulus of the composite and restricts plastic deformation of the polymer matrix.

  • on the reduced susceptibility to stress whitening behavior of melt intercalated Polybutene clay nanocomposites during tensile straining
    Acta Materialia, 2004
    Co-Authors: H Nathani, Aravind Dasari, R D K Misra
    Abstract:

    The paper describes the micro-scale response, mechanism, and susceptibility to stress whitening during tensile straining of Polybutene-5 wt% clay nanocomposites, and its comparison with unreinforced neat Polybutene utilizing electron microscopy observations. Polybutene-5 wt% clay nanocomposites exhibit increased tensile modulus, significantly reduced susceptibility to stress whitening, and are characterized by lower optical gray level in the plastically deformed stress whitened zone. Furthermore, crystallization studies suggest that the reinforcement mineral increases the rate of nucleation, accelerating the crystallization process. The reinforcement of Polybutene with 5 wt% clay alters the primary micromechanism of stress whitening from stress relaxation of the 'fish-scale psiloma' containing tiny voids and subsequent transformation to ridge tearing at high plastic strains to nucleation and growth of large size voids in Polybutene-clay nanocomposites. The final fracture in neat Polybutene occurs by a mixed mode (brittle and fibrillation), while brittle deformation is the predominant fracture mode in Polybutene-5 wt% clay nanocomposites.

Dujin Wang - One of the best experts on this subject based on the ideXlab platform.

Alejandro J Muller - One of the best experts on this subject based on the ideXlab platform.

H Nathani - One of the best experts on this subject based on the ideXlab platform.

  • The determining role of clay particles on mechanically induced surface damage and associated stress whitening in Polybutene–clay nanocomposites
    Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2004
    Co-Authors: R D K Misra, H Nathani, Aravind Dasari, S D Wanjale
    Abstract:

    Abstract The potential of atomic force microscopy to quantify the surface topography is combined with the surface features obtained by electron microscopy to examine susceptibility to mechanically induced surface damage in neat Polybutene and Polybutene–clay nanocomposites. The scratch tracks in Polybutene are characterized by ‘fish-scale psiloma’ morphology indicative of compressive plastic deformation and quasi-periodic cracking. While in Polybutene–clay nanocomposites, ‘ironing’, which is a less severe surface damage mechanism was dominant. Also, Polybutene–clay nanocomposites experience significantly reduced stress whitening, and is characterized by lower gray level in the plastically deformed surface damage region. This behavior is attributed to the effective reinforcement by clay particles that act in concert increasing the tensile modulus of the composite and restricts plastic deformation of the polymer matrix.

  • the determining role of clay particles on mechanically induced surface damage and associated stress whitening in Polybutene clay nanocomposites
    Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2004
    Co-Authors: R D K Misra, H Nathani, Aravind Dasari, S D Wanjale
    Abstract:

    Abstract The potential of atomic force microscopy to quantify the surface topography is combined with the surface features obtained by electron microscopy to examine susceptibility to mechanically induced surface damage in neat Polybutene and Polybutene–clay nanocomposites. The scratch tracks in Polybutene are characterized by ‘fish-scale psiloma’ morphology indicative of compressive plastic deformation and quasi-periodic cracking. While in Polybutene–clay nanocomposites, ‘ironing’, which is a less severe surface damage mechanism was dominant. Also, Polybutene–clay nanocomposites experience significantly reduced stress whitening, and is characterized by lower gray level in the plastically deformed surface damage region. This behavior is attributed to the effective reinforcement by clay particles that act in concert increasing the tensile modulus of the composite and restricts plastic deformation of the polymer matrix.

  • on the reduced susceptibility to stress whitening behavior of melt intercalated Polybutene clay nanocomposites during tensile straining
    Acta Materialia, 2004
    Co-Authors: H Nathani, Aravind Dasari, R D K Misra
    Abstract:

    The paper describes the micro-scale response, mechanism, and susceptibility to stress whitening during tensile straining of Polybutene-5 wt% clay nanocomposites, and its comparison with unreinforced neat Polybutene utilizing electron microscopy observations. Polybutene-5 wt% clay nanocomposites exhibit increased tensile modulus, significantly reduced susceptibility to stress whitening, and are characterized by lower optical gray level in the plastically deformed stress whitened zone. Furthermore, crystallization studies suggest that the reinforcement mineral increases the rate of nucleation, accelerating the crystallization process. The reinforcement of Polybutene with 5 wt% clay alters the primary micromechanism of stress whitening from stress relaxation of the 'fish-scale psiloma' containing tiny voids and subsequent transformation to ridge tearing at high plastic strains to nucleation and growth of large size voids in Polybutene-clay nanocomposites. The final fracture in neat Polybutene occurs by a mixed mode (brittle and fibrillation), while brittle deformation is the predominant fracture mode in Polybutene-5 wt% clay nanocomposites.

Yongna Qiao - One of the best experts on this subject based on the ideXlab platform.

  • spontaneous form ii to i transition in low molar mass Polybutene 1 at crystallization temperature reveals stabilization role of intercrystalline links and entanglements for metastable form ii crystals
    Macromolecules, 2018
    Co-Authors: Yongna Qiao, Fei Yang, Ying Lu, Yuesheng Li
    Abstract:

    As for the solid–solid transformation from form II to form I in Polybutene-1, the intercrystalline links in amorphous phase and the temperature difference between crystallization and phase transition were thought to be essential in previous studies for generating the internal stress to promote nucleation and growth of the phase transition. In this work, we report experimental evidence showing that such a transition can be accomplished without supercooling at the temperature of crystallization directly in a low molar mass sample where there are almost no intercrystalline links. This result reveals two significant aspects of the form II to I transition in Polybutene-1 against conventional wisdom: (1) the nucleation barrier of the transition is very low and can be overcome by thermal fluctuation; (2) entanglements and intercrystalline links in high molar mass systems play a role of stabilizing the metastable form II via hindering the translational movements of chains in crystalline phase and slowing the rela...

  • retardance of form ii to form i transition in Polybutene 1 at late stage a proposal of a new mechanism
    Macromolecules, 2018
    Co-Authors: Yongna Qiao, Hai Wang
    Abstract:

    The retardation of Polybutene-1 form II to form I transition in the late stage has been investigated by means of time-resolved wide-angle X-ray diffraction. Form II samples with different lamellar thickness and constituent in amorphous phase were generated via varying crystallization temperature and molecular weight and aged at room temperature for the form II to form I transition. The II to I polymorphic transition in Polybutene-1 undergoes two stages, where slow nucleation and rapid growth proceed in the first stage and extremely slow secondary nucleation and growth take place in the late stage. The degree of transition reaches a plateau value in the late stage of transition, which depends highly on crystallization temperature and molecular weight that low molecular weight and high crystallization temperature always contribute to a greater degree of transition, but is less affected by the kinetics in the first stage. According to the crystal unit cell parameters of form II and form I, there should be an...