2 edition of Molecular modelling of the elastic behaviour of polymer chains in networks found in the catalog.
Molecular modelling of the elastic behaviour of polymer chains in networks
D. J. R. Taylor
|Statement||D.J.R. Taylor ; supervised by R.F.T. Stepto.|
|Contributions||Stepto, R.F.T., Materials Science Centre.|
The effect of main chain stiffness and side chain flexibility on the elastic modulus and glass transition temperature (T g) of thin polymer films is investigated using nontraditional polymers formed from 5-(2-phenylethylnorbornene).Depending on the polymerization route chosen, the resulting polymer backbone is comprised of either bicyclic (norbornyl) units, which leads to a . Article Views are the COUNTER-compliant sum of full text article downloads since November (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days. Citations are the .
The term ‘polymer’ refers to large molecules whose structure is composed of multiple repeating units and the prefix ‘supra’ meaning ‘beyond the limits of’. Supramolecular polymers are a new category of polymers that can potentially be used for material applications beyond the limits of conventional polymers. By definition, supramolecular polymers are polymeric arrays of . In the case of polymer networks, the effect of a related measure of chordless cycle size, the smallest loop size, has been shown analytically and numerically as a negative correction (e.g., see ref. 22) to the elastic other materials, the nature of the physical constraints can be expected to change the details of the finite-size behavior, particularly if the .
So the basic approach to build a polymer chain is to put together the atoms that make up the chain (carbon and hydrogen, for example, if you are simulating polyethylene). This is an “atom-based” (atomistic) simulation. It is the most detailed type of molecular polymer . Chemically cross-linked thermoset shape memory polymers (TSMPs) are an important branch of smart materials due to their potentially wide applications in deplorable structures, sof.
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Jump to main content. Jump to site search. Publishing. 1. Introduction. Calculations of elastomeric properties of polymer networks have conventionally used theories and models based on the behaviour of a collection of ‘average’ chains, with all the chains responding identically to external forces.To explain experimental behaviour, such approaches require the unrealistic postulate of a transition from affine to phantom chain behaviour Cited by: Simulations of model networks In this paper we summarize results of molecular dynamics simulations of model polymer networks with diamond lat-tice connectivity, where we have exploited all of the advan-tages mentioned above.
Such systems, which cannot be pre-pared experimentally, are free of “chemical” defects in the network structure. The tetrahedral element merely serves to model the near-incompressible behaviour of the polymer network and is therefore of macroscopic nature.
It is important to mention that the length of a truss element is in no way linked to the length of a polymer chain or to the average length of the chains belonging to the corresponding chain by: The problem of adsorption of polymer chains on a solid flat surface in absence of polymer flow was extensively studied.
A comprehensive review of this topic is presented in the monograph by Fleer et presence of polymer flow, a number of models are proposed for the attachment/detachment dynamics of chains on/from flat surfaces.Here we take a view Cited by: We develop and solve a new molecular model for nonlinear elasticity of entangled polymer networks.
This model combines and generalizes several succeseful ideas introduced over the years in the field of the rubber elasticity. The topological constraints imposed by the neighboring network chains on a given network are represented by the confining potential that. Taylor Impact Behavior of “Model” Glassy and Rubbery Polymers.
The Taylor impact behavior of the “model” hyperelastic (rubbery) and elastic-plastic (glassy) polymers was examined in terms of energy dissipation and resilience. Up to date, two-network model is widely used to describe elastic behavior for polymer temper-ature aging,7 oxidative aging,8 radiation aging,6,9,10 double network,9,10 transient network,11,12 and so on.
In addition, molecular dynamics simulations have conﬁrmed the two-network model and explained the stress-transfer function− Biological and polymeric networks show highly nonlinear stress–strain behavior manifested in materials that stiffen with increasing deformation.
Using a combination of the theoretical analysis and molecular dynamics simulations, we develop a model of network deformation that describes nonlinear mechanical properties of networks and gels by relating their macroscopic strain-hardening behavior. ROBERT SCHIRRER, in Handbook of Materials Behavior Models, GLASSY AND RUBBERY STATES.
Amorphous polymers are in their glassy state below the glass transition temperature T g and rubbery above this temperature. Below T g, the short-range molecular interactions between nonlinked atoms are strong and local loads are carried from atom to a small elastic.
Polymers exhibit a wide range of stress-strain behaviors as shown in the figure below. The brittle polymer (red curve) elastically deforms and fractures before deforming plastically. The blue curve is a plastic polymer and is similar to curves for many metals.
Its behavior begins in the linear elastic deformation region. Primitive chain network model S95 where ζ b is the frictional coefﬁcient of the branching point, i.e. ζ b = q 4 ζ. (10) Although the branch point moves in space according to equation (9), it.
Entangled polymer solutions and melts exhibit elastic, solid-like resistance to quick deformations and a viscous, fluid-like response to slow deformations. This viscoelastic behaviour reflects the. Polymer Chains and Networks in Narrow Slits Two models of the flexible molecular chains have been used—one with a linear stress‐extension relation (Gaussian chain), the second with.
model considers the polymer as a series of orienta-tionally independent statistical segments (Kuhn segments), whose length is a direct measure of the chain stiffness. The WLC model, on the other hand, treats the polymer as a relatively stiff rod made up of a homogeneous elastic material (elastica).
In this model, the stiffness of the chain is. However, one of the important characteristics of polymer molecules is their ability to change size and shape over wide extremes.
It is impossible using static models to give a correct description of the configurational behaviour of polymer chains. A model is presented for the elasticity of networks composed of rigid chains. The elastic modulus as a function of polymer volume fraction is determined for two cases: (a) the chains.
The molecular theory of rubber elasticity rests on the premise, now fully validated by experiments, that alterations of the configurations of the chains.
The Molecular Kink Paradigm proceeds from the intuitive notion that molecular chains that make up a natural rubber (polyisoprene) network are constrained by surrounding chains to remain within a ‘tube’.Elastic forces produced in a chain, as a result of some applied strain, are propagated along the chain contour within this tube.
Fig. 2 shows a representation of a four. Molecular modelling of the elastic behaviour of polymer chains in networks. on the basis of the rotational-isomeric state model of polymer chains.
Diamond lattice chains were generated by a. Polymer physics is the field of physics that studies polymers, their fluctuations, mechanical properties, as well as the kinetics of reactions involving degradation and polymerisation of polymers and monomers respectively.
While it focuses on the perspective of condensed matter physics, polymer physics is originally a branch of statistical r physics and polymer .where k B is Boltzmann's constant, ζ o is the monomer friction coefficient, N is the number of monomer units (or segments) in the polymer backbone, and R e is the average end‐to‐end distance of polymer chain.
A polymer chain diffuses a distance on the order of its size during a time interval proportional to the chain relaxation time. 82 In.In this work we analyze the influence of low concentrations of pendant chains on the viscoelastic properties of polymer networks.
Model networks, with a well defined structure, were synthesized by.