Rheology and Structural Properties of Hyperbranched Polymers: a Non-Equilibrium Molecular Dynamics Study

Le, Tu C.; Todd, Billy D.; Daivis, Peter J.; Uhlherr, Alfred
July 2008
AIP Conference Proceedings;7/7/2008, Vol. 1027 Issue 1, p433
Conference Proceeding
Hyperbranched polymers are imperfectly branched or irregular tree-like structures that have special properties and potential applications in various areas such as thermoset resins, toughening agents and drug delivery. They can be synthesized economically by one-pot reaction which adapts well to large-scale production but provides a polydisperse mixture of randomly branched polymers with different size and topology. This leads to difficulties in experiments and gives simulation a valuable opportunity to gain further insight in understanding the structure and rheology of hyperbranched structures. They have been simulated using bead-rod models together with Monte Carlo and Brownian dynamics techniques. In this research, hyperbranched polymers were simulated using coarse-grained uniform beads and non-equilibrium molecular dynamics (NEMD) methods. Polymeric chains are composed of interconnected beads interacting via finitely extensible nonlinear elastic (FENE) and Weeks-Chandler-Anderson (WCA) potentials. Viscoelastic properties and structural changes of trifunctional hyperbranched polymers in the melt undergoing planar shear are investigated. Our results are in the range between those of dendrimers and linear analogues of equivalent molecular mass.


Related Articles

  • A molecular dynamics investigation of the planar elongational rheology of chemically identical dendrimer-linear polymer blends. Hajizadeh, Elnaz; Todd, B. D.; Daivis, P. J. // Journal of Chemical Physics;2015, Vol. 142 Issue 17, p1 

    The structure and rheology of model polymer blends under planar elongational flow have been investigated through nonequilibrium molecular dynamics simulations. The polymeric blends consist of linear polymer chains (187 monomers per chain) and dendrimer polymers of generations g = 1 - 4. The...

  • Addressing Unsolved Mysteries of Polymer Viscoelasticity. Larson, Ronald G. // AIP Conference Proceedings;2/21/2008, Vol. 982 Issue 1, p419 

    By using coarse-grained bead-spring and entanglement tube models, much progress has been made over the past 50 years in understanding and modeling the dynamics and rheology of polymers, both in dilute solution state and in entangled solutions and melts. However, several major issues have...

  • Shear rheology and structural properties of chemically identical dendrimer-linear polymer blends through molecular dynamics simulations. Hajizadeh, Elnaz; Todd, B. D.; Daivis, P. J. // Journal of Chemical Physics;11/21/2014, Vol. 141 Issue 19, p1 

    We present nonequilibrium molecular dynamics (NEMD) simulation results for the miscibility, structural properties, and melt rheological behavior of polymeric blends under shear flow. The polymeric blends consist of chemically identical linear polymer chains (187 monomers per chain) and dendrimer...

  • Challenges in Multiscale Modeling of Polymer Dynamics. Li, Ying; Abberton, Brendan C.; Kroger, Martin; Liu, Wing Kam // Polymers (20734360);Jun2013, Vol. 5 Issue 2, p751 

    The mechanical and physical properties of polymeric materials originate from the interplay of phenomena at different spatial and temporal scales. As such, it is necessary to adopt multiscale techniques when modeling polymeric materials in order to account for all important mechanisms. Over the...

  • Concentration effects on lubrication rheology for polymer solution in molecularly thin film using molecular dynamics. Yeau-Ren Jeng; Chia-Chen Chen; Shiuh-Hwa Shyu // Journal of Applied Physics;6/15/2004, Vol. 95 Issue 12, p8450 

    The current study utilized a molecular dynamics (MD) method to investigate the concentration effects of the mixture with polymer and monatomic liquid on the lubrication rheological properties. Fluids considered were confined in a molecularly thin film in which the number of molecular layers and...

  • Free energy calculations of small molecules in dense amorphous polymers. Effect of the initial guess configuration in molecular dynamics studies. van der Vegt, Nico F. A.; Briels, Wim J.; Wessling, Matthias; Strathmann, Heiner // Journal of Chemical Physics;11/15/1996, Vol. 105 Issue 19, p8849 

    The excess free energy of small molecules in the amorphous polymers poly(ethylene) and poly(dimethylsiloxane) was calculated, using the test-particle-insertion method. The method was applied to polymer configurations obtained from molecular dynamics simulations with differently prepared initial...

  • The collapse of chains with different architectures. Raos, Guido; Allegra, Giuseppe; Ganazzoli, Fabio // Journal of Chemical Physics;5/15/1994, Vol. 100 Issue 10, p7804 

    The equilibrium properties and the Rouse–Zimm dynamics of polymer molecules with any architecture at temperatures T≤Θ, are treated using a bead-and-spring coarse-grained description. The collapsed globule model is adopted, whereby essentially all atoms are at the same mean-square...

  • Temperature echoes revisited to probe the vibrational behavior of dendrimers. Paulo, Pedro M. R. // Journal of Chemical Physics;3/21/2010, Vol. 132 Issue 11, p114901 

    Temperature quench echoes were induced in molecular dynamics simulations of dendrimers. This phenomenon was used to probe the vibrational behavior of these molecules by comparing simulation results with harmonic model predictions. The echo depth for short time intervals between temperature...

  • Molecular dynamics study of charged dendrimers in salt-free solution: Effect of counterions. Gurtovenko, Andrey A.; Lyulin, Sergey V.; Karttunen, Mikko; Vattulainen, Ilpo // Journal of Chemical Physics;3/7/2006, Vol. 124 Issue 9, p094904 

    Polyamidoamine dendrimers, being protonated under physiological conditions, represent a promising class of nonviral, nanosized vectors for drug and gene delivery. We performed extensive molecular dynamics simulations of a generic model dendrimer in a salt-free solution with dendrimer’s...


Read the Article


Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics