Questions tagged [polymers]
Polymers is concerned with the physical properties of individual macromolecules. For questions regarding bulk behavior of ensembles of polymers, the [condensed-matter] tag may be more appropriate.
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Reason for very low speed of sound in rubber
I just came by a table in the Class 11 Physics NCERT textbook, listing speeds of sound in different media.
Vulcanised rubber has an unusually low speed of sound $54\ \mathrm{m}/\mathrm{s}$ as compared ...
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Reference Request - Modern Polymer Dynamics
I'm an applied math graduate student studying the cytoskeleton. I wanted to know of any reference(s) providing the most general mathematical theory of polymer dynamics, think an updated version of Doi ...
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Derivation of the upper convected time derivative
I read on wikipedia theat the upper convected time derivatvie is the rate of change of some tensor property of a small parcelof fluid that is written in the coordinate system rotating and stretching ...
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How to calculate path integral of polymer system?
We have the functional integral $(1)$ of viriable $\delta p_j$. In our case this intergral follows from RPA (random phase approximation) method assuming $\ p_j(r)=p_j^*+\delta p_j(r)$. The task is to ...
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Does crosslinking a polymer film increase the stress within the film?
If I crosslink a polymer film, does that increase the internal stress of the film? Intuitively I think it should for entropy reasons; chains with greater links are more restricted and have a smaller ...
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How do UV light curable adhesives work?
How do UV light curable adhesives (such as Loctite's and Permabond's UV glues) work? What gives them the ability to join two non-porous surfaces such as glass-to-glass, glass-to-metal?
Also, do ...
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How to theoretically determine thermal emissivity of thin polymeric films?
Maybe someone could help with determining gray-body emissivity of thin films such as polyethylene. There is a lot of conflicting data online with some sources stating polyethylene's epsilon value as 0....
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Linking elastic moduli to shape fluctuations
I am simulating a polymer network shaped as a sphere. I would like to compute its elastic moduli (bulk and Young's, for example) not by their shear-strain definition but by looking at the fluctuations ...
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Why do rubber bands at higher temperatures stretch more?
I did an experiment where i placed a rubber band in water at different temperatures (-15°C till 90 °C) , and then a put a constant mass on the rubber band, to see how far it would stretch.
What i ...
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Elasticity of rubber bands at varying temperatures
So what i read online was that when rubber bands can stretch (become more elastic) more when their at colder temperatures. How i understood is that entropy allows for the molecules to align up more ...
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Unexpected behaviour in numerical simulation of polymer
I noticed some strange behaviour when simulating the behaviour of a polymer subjected to an external pulling force at both ends, and would like to better understand its origin.
I used LAMMPS to ...
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Understanding roles of energy and entropy in different polymer models
Polymers can be modeled as ideal chains and bead-springs (among other various models). However, in an ideal chain, the interactions are entirely entropic, whereas in the bead-spring model, there are ...
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Relationship between Kuhn length and persistence length
What is the persistence length of poly(N-isopropyl acrylamide)? Is there a definite relation between kuhn length and persistence length? I know that the persistence length is considered to be one ...
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Why melting temperature of polymers depends on the prior crystallization temperature?
This graph should show that the melting temperature of a polymer rises when the crystallization temperature of a polymer was higher (the melting temperature of a 100% crystalline polymer should be ...
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Simple model of a polymer
Let's describe a polymer as a linear chain of $N$ links which all have a bendable part. The energies of one link are $\epsilon_-$ (unbended) and $\epsilon_\wedge$ (bended). Additionally, the lengthsof ...
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