What is Polymer: Definition and 108 Discussions

A polymer (; Greek poly-, "many" + -mer, "part")
is a substance or material consisting of very large molecules, or macromolecules, composed of many repeating subunits. Due to their broad spectrum of properties, both synthetic and natural polymers play essential and ubiquitous roles in everyday life. Polymers range from familiar synthetic plastics such as polystyrene to natural biopolymers such as DNA and proteins that are fundamental to biological structure and function. Polymers, both natural and synthetic, are created via polymerization of many small molecules, known as monomers. Their consequently large molecular mass, relative to small molecule compounds, produces unique physical properties including toughness, high elasticity, viscoelasticity, and a tendency to form amorphous and semicrystalline structures rather than crystals.
The term "polymer" derives from the Greek word πολύς (polus, meaning "many, much") and μέρος (meros, meaning "part"), and refers to large molecules whose structure is composed of multiple repeating units, from which originates a characteristic of high relative molecular mass and attendant properties. The units composing polymers derive, actually or conceptually, from molecules of low relative molecular mass. The term was coined in 1833 by Jöns Jacob Berzelius, though with a definition distinct from the modern IUPAC definition. The modern concept of polymers as covalently bonded macromolecular structures was proposed in 1920 by Hermann Staudinger, who spent the next decade finding experimental evidence for this hypothesis.Polymers are studied in the fields of polymer science (which includes polymer chemistry and polymer physics), biophysics and materials science and engineering. Historically, products arising from the linkage of repeating units by covalent chemical bonds have been the primary focus of polymer science. An emerging important area now focuses on supramolecular polymers formed by non-covalent links. Polyisoprene of latex rubber is an example of a natural polymer, and the polystyrene of styrofoam is an example of a synthetic polymer. In biological contexts, essentially all biological macromolecules—i.e., proteins (polyamides), nucleic acids (polynucleotides), and polysaccharides—are purely polymeric, or are composed in large part of polymeric components.

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  1. vasschina

    Calculate the theoretical yield of a polymer (polysuccinimide)

    Hello everyone, I am trying to find how to calculate the theoretical yield of polysuccinimide I synthesized from the aspartic acid. I added 10g of Asp and i took 7,3g of PSI. Someone who knows how to find the yield?
  2. hagopbul

    B Is this material is good for fiber optics and who would buy it?

    Hello All : as i try to create better economical situation for my self , as some of you noticed that i tried to enhance few things in engines , although it did not quaitly work out it lead to another invention , i couldnt change it yet to economical benefit , due to tests required , and dont...
  3. S

    XRD Result Analysis on Polymer

    So i just have my XRD result (Polymer Specimen) which i use to determine crystallinity of my material, and it turns out that my material has no obvious peak, and have a broad peak which usually associated with amorphous material. I added some filler to my material and it became more and more...
  4. user366312

    Polymer simulation source code in C++ and Python

    I am absolutely new to Polymer simulation. I am trying to understand the simulation by analyzing source code written by others. Can anyone tell me what are the differences between the following three source code in terms of their objectives? Monte-Carlo-simulation-of-polymers...
  5. S

    Polymer linear bearing grooves

    All polymer linear bearings i have seen have a lot of groves in the running direction (at least the ones for round shafts). Is this just to minimize the surface area in contact with the shaft to minimize the friction? Or do they have another function like clearing dust and particles? And why...
  6. Mayhem

    Theoretical Possibility of a N-methyl Polymer Structure

    Out of sheer curiosity, would a polymer of the following structure be theoretically possible? Imagine that the "N-methyl" groups are just the bounds of what is shown, and not actual carbon-containing substituents... It doesn't seem to break any elementary bonding rules. However, the C-C bond...
  7. mcconnellalex01

    Biology Polymer vs. Macromolecule: What's the Difference?

    I am aware that there is a difference between a polymer and a macromolecule (due to types of bonds, structure, etc.) but all of these seem to be chains like polymers to me. I know that is incorrect because there is no option for all of the above.
  8. E

    How do you calculate the Kuhn length of a polymer?

    My lecturer said that as a first approximation, we can take the polymer chain to consist of ##n## freely jointed rods of length ##l##. That's just going to give$$\langle \vec{R}_n^2 \rangle = \langle \sum_{i=1}^n \vec{r}_i \cdot \sum_{j=1}^n \vec{r}_j \rangle = \langle \sum_{i=1}^n \sum_{j=1}^n...
  9. E

    Mixing of two polymer particles heated above Tg

    I am wondering if two polymer particles, of same kind, heated above Tg can be mixed, over time, if they are squeezed together. By mixing I mean that the surfaces of the two particles will mix into one after they are squeezed together. For simplicity let's assume that the polymer particles are...
  10. omega_minus

    A Effective Spring Constant of a Chain Polymer

    Hi All, I'm doing research in magnetic nanoparticles that are coated with chain molecules (oleic acid, I believe) and I am trying to model these molecules' effective spring constant. The basic scenario is this: When a water-based ferrofluid is evaporated, it leaves behind only dried...
  11. E

    Battery to support Polymer Dispersed Liquid Crystal (PDLC) Film

    We are incorporating a PDLC layer into a product being developed by us and it requires almost constant activation to remain transparent. The PDLC draws 0.557 Watts of power per hour at 60VAC. The goal is to get a battery/power source (of any type even proprietary) to last the upwards of 26,000...
  12. CharlieCW

    One-dimensional polymer (Statistical Physics)

    Homework Statement Consider a polymer formed by connecting N disc-shaped molecules into a onedimensional chain. Each molecule can align either its long axis (of length ##l_1## and energy ##E_1##) or short axis (of length ##l_2## and energy ##E_2##). Suppose that the chain is subject to tension...
  13. M

    A Colloidal suspensions, Polymer solutions

    What does it mean colloidal suspensions, polymer solutions? in flow of fluid.
  14. S

    Polymer Chain in Statistical Mechanics

    Homework Statement A polymer chain consist of a large number N>>1 segments of length d each. The temperature of the system is T. The segments can freely rotate relative to each other. A force f is applied at the ends of the chain. Find the mean distance ##\textbf{r}## between the ends...
  15. Abhijit Nath1991

    Polymer nanocomposite -- Which is the most emerging application field?

    I am working on polymer nanocmposite. I want suggestion regarding the application of it. Which is the most emerging application field of PNC ?
  16. mkematt96

    Linear Abrasion Testing PVC/Polymer Blend Hoses

    Working on a research project to develop a test standard for abrasion testing pressure washer hoses. Ideally this could be used on any sort of hose. We have a set procedure that has worked on a couple hoses that looks like this: .Weight applied is constant .Cycle speed is constant .Constant...
  17. Quentin_alex

    Differential scanning calorimetry of nylon 6

    Hello, I ran a test on an industrial composite of 30% glass-filled nylon 6, and my melting temperature peak is too low. The range was from -30 C to 275 C. Why could this be happening? Should I suspect the sample pan? Thanks.
  18. not_a_chemist

    Chemical Polymer Separation (PLA, ABS, HIPS, and PETG)

    Good day all! I've got a granular mixture of PLA, ABS, HIPS, and PETG with a particle size of about a quarter inch, and I'm trying to isolate each polymer from the mix. PLA and PETG have densities of about 1.27g/ml, and ABS and HIPS have densities of around 1.06g/ml. I think a weighted solution...
  19. klotza

    Insights New Research on Untying Knots in Polymers - Comments

    Greg Bernhardt submitted a new PF Insights post New Research on Untying Knots in Polymers Continue reading the Original PF Insights Post.
  20. G

    Polymer Physics: molar mass, polymerization

    Homework Statement Consider a “true macromolecule” - a chunk of polybutadiene network of mass 100g. How many monomers all covalently bonded together does it contain if the molar mass of the monomer is Mmon= 54g/mol? What is the molar mass of this macromolecule? Homework Equations Molar mass...
  21. Kelly Lin

    Probability of the polymer chain

    Homework Statement Homework Equations I want to check if I think it right! The Attempt at a Solution If N=1: ← or → (2 configurations/ each length is l) N=2: ← or → or ←← or ←→ or →← or →→ ------→----← (6 configurations/ folded polymer's length is l/2 andunfolded polymer's...
  22. C

    I Polymer Physics - Radius of Gyration

    I was not sure if this was the best place for this, it could fit here, in the Chemisty section or the Programming section. So feel free to move if needed. Essentially I have been modeling polymers in python and using a Monte Carlo, Metropolis type algorithm, to minimise its energy into...
  23. mesa

    Looking for information on Celanese Fortiflex polymer

    Hey guys, I am trying to located more information on a polymer that was called celanese fortiflex. It was used in TRIGA nuclear reactors to hold samples in a high neutron flux and was developed (I believe) around the early 1960's. Some modern PE materials have been tested, but fall apart after...
  24. S

    Experiments with interfacial polymerization

    I'm wanted to do an experiment with interfacial polymerization; producing nylon 6,10 with sebacoyl chloride and hexanediamine. I was wondering what aspects of this reaction I could research, or what variables I can change?
  25. Funner

    Electrostatic force on polymer particle in an electric field

    Hi there, in electrospinning, a positive charge of around 10.000Volt is applied to a needle, where a viscous polymer is extruded. There is a grounded collector in a distance of 15mm and the established electrical field generates electrostatic forces and draws a thin polymer jet to the...
  26. S

    What are possible polymer chemistry experiments?

    I was wondering if there were any possible experiments that I can conduct in a high school lab setting.
  27. klotza

    Insights Polymer Physics and Genetic Sequencing - Comments

    klotza submitted a new PF Insights post Polymer Physics and Genetic Sequencing Continue reading the Original PF Insights Post.
  28. Seeker3

    DSC Polymer Characterisation interpretation help

    Hi respected peers, Firstly, i must apologise in advance for any error i may make within this forum, I'm a new member here. The question i wish to ask is with regards to observing a glass transition and crystallisation peak upon cooling, however without observing the obvious melt of a polymer...
  29. C

    A thermodynamics polymer chain problem

    A one-dimensional polymer molecule (rubber) is chain of N links of the same length a, the links can go either forward or backward but always stay parallel to the x axis. If one denotes the coordinates of the joints are ${x_0, x_1, . . . , x_N}$ , then $|x_n − x_{n+1}| = a$. The energy of the...
  30. W

    Coursework Chemistry Project -- Idendification of different types of polymer

    Homework Statement Topic : Idendification of different types of polymer Suggested materials : Plastic bottles or materials Sugeested methods of analysis : Volumetric analysis, Chromatography ,pH, Solvent extration, Distillation General purpose of project : To inculcate awareness on health and...
  31. U

    Can someone explain peierls distortion/transition to me?

    Peierls distortion states that for a 1 dimensional polymer (like polyacyteline) with lattice spacing a they should have a half-filled conduction band, why? And how does changing the lattice space to 2a cause it to form an energy gap? In my mind it should be the same as the first case...
  32. J

    Chemistry Number of moles of polymer formed

    Homework Statement 2. The attempt at a solution I chose no. 1 only, but the answer is 2&3, I can't seem to see how 10^-6 came about. And for C, I'm not clear how it came about too.. Is it because 1 mole consists of 6x10^23 atoms, so no. of moles of the polymer is 1/(6x10^23) ? And why is 1...
  33. Stephanus

    Carbon-Based Life: Questions & Answers

    Dear PF Forum, I have questions about carbon based life and molecule back bone. Is it true that all life on Earth are carbon based? If it is true, why? Is it because carbon is halfway in periodic table? 4 valence? What about Silicon, Tin and Germanium? They have 4 valence, why life is not based...
  34. Y

    Volume Fraction of a Polymer

    I have a tutorial question that I'm not too sure of. The question states: Calculate the volume fraction Φ for a polymer solution of concentration C (given in g/L) and hydrodynamic radius R? The answer was given as...
  35. H

    Measurement of viscosity of polymer

    Homework Statement if we have only a measuring cylinder (500mm high and 50mm diameter), a stop-watch, a ruler and a 100μL syringe. We assume that the density of the suspension is 1g/cm3, and that the polymers are spherical How can we determine the viscosity and the volume fraction of the...
  36. P

    Polymer/Propellant Solution

    Ok, I am really close to this. d-Limonene dissolves Polystyrene (I have tested this) and Liquid Isobutane mixes with d-Limonene (I have also tested this) However, when I mix all three together, the Polystyrene becomes completely separated from the solution. Same thing with all polymer solutions...
  37. R

    Flash freezing of polymer

    Hello, I am working on a science fair project with my son. His project is about the mobility of polymer chains depending on temperature and pressure. As part of his project we want to flash freeze a piece of plastic to show how brittle it becomes. We bought instamorph, which is polycaprolactone...
  38. T

    Polymer Solution Thermodynamics: Flory-Huggins Theory of Polymer Solutions

    Homework Statement (Note: This isn't an assignment problem, more a curiosity about the derivation of an equation - hopefully it is still posted in the right forum..) I have working through the derivation for the partial molar Gibbs free energy of mixing from the Flory-Huggins expression for...
  39. C

    Stretching Some Polymer

    The question tells me that some experiments have shown that the force needed to stretch a polymer molecule by an amount (Δl) is given approximately by: F= (kBT/P)*((1/4)*(Lo2/(L-Δl)2-(1/4)+(Δl/L)) Yea, I know, nasty looking. Anywho: F = Force T = Temp. kB = Boltzmann's Constant P =...
  40. F

    Intrinsic viscosity of a polymer and its density

    Hello Forum, I have two polymers (both in pellet form). Their spec sheet shows that the two polymers have different intrinsic viscosity IV. There are so many definitions of viscosity (dynamic, intrinsic, inherent, etc.) In general viscosity and density are two independent properties of a...
  41. WannabeNewton

    1-dimensional polymer in gravitational field

    Homework Statement A rubber band at temperature ##T## is fastened at one end to a peg and supports from its other end a weight ##W##. Assume as a simple microscopic model of the rubber band that it consists of a linked polymer chain of ##N## segments joined end to end; each segment has length...
  42. P

    Spectroscopy technique for detecting water saturation front in polymer

    Hello all, I am a grad student in materials science. As part of a research project, I need to measure/detect the velocity of a water saturation front moving through polymers (a few materials, most fluoro/perfluoropolymers). The ultimate goal of the project is to determine the permeability of...
  43. L

    Liquid - polymer equilibrium "contact" distance

    Hi everyone, In this paper ( http://pubs.acs.org/doi/abs/10.1021/la962131c ), the authors calculate the surface energy of polymer and the contact angle of various liquids on these polymers using a so-called "liquid - polymer equilbrium contact dsitance". I'm wondering how to calculate such a...
  44. M

    Observation of a single polymer chain

    Hi, I have a question regarding polymers. You know that polymers, basically, consist of chains of polymers, each chain including number of repeating units (monomer). These chains can be in amorphous or crystalline states. Experimentally, is it possible to fabricate and see a single chain...
  45. Y

    Materials - Modulus of polymer and metal

    Homework Statement Why is there such a large difference between the elastic moduli of metals and polymers? Homework Equations The Attempt at a Solution I am thinking because of the different bonding between metals and polymers. Since metals have metallic bonding and polymers...
  46. S

    Statistical physics - average length of polymer

    Homework Statement A polymer consits of ##10^{20}## monomers, each 2 nm long. One end of the polymer is hanged at the ceiling on the other end, we have a load of ##4\cdot 10^{-10}g##. Calculate the average potential energy! Homework Equations The Attempt at a Solution Well... I don't...
  47. K

    How to extract bubbles gas from gel(Super Absorbent Polymer)

    I have been thinking to extract gases from SAP (the gel is super absorbent polymer(sodium polyacrylate)). The gases are trapped inside the gel in form of bubbles gas. I am thinking of using salt to turn it back to liquid or using vacuum pump to extract gas out. Using salt might be the best way...
  48. S

    Thermodynamics - (polymer) caluclate the average potential energy

    Homework Statement A polymer of ##10^{20}## molecules each 2nm long is hanged from the ceiling. The other end of the polymer is attached to a ##m=4\cdot 10^{-10} g## load. Calculate the average potential energy! Temperature is 300 K. Homework Equations ##<E>=<E_p>=\frac{\mathrm{d} (\beta...
  49. O

    GPC - Polymer solvent compatibility

    Homework Statement Given for polystyrene K = 1.6x10^5 and a = 0.71 and for PVC K = 1.5x10^5 and a = 0.77 a universal calibration curve has been created from PS and the molar mass of PVC at a certain elution volume has been calculated. The part I'm not sure on is the question: Show which of...
  50. Y

    Polymer low permeability for balls

    I have 2 interesting questions, I believe, regarding polymer properties. I am designing a ball (pretty much like a basketball in size and appearance) to be used inside pressure vessels for certain corrosive fluids. The ball is inflated with air to a certain pressure in order to cushion extreme...