What is Polymers: Definition and 54 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. bo reddude

    Exploring the Math of Glucose Polymers: Understanding 6^n

    Let's say you have n glucose monomers. (C6H12O6) n You want to find out how many possible polymers exist in combining those n number of glucose molecules randomly. So glucose_1 has 6 OHs that can combine with glucose_2 which also has 6 OHs. Starting with glucose_1's first carbon C1, at that...
  2. A

    How Does Paracrystallinity Influence Charge Transport in Conjugated Polymers?

    "In the case of negligible paracrystallinity, the density of states (DOS) of the 1D pi-stack depends on the amount of on-site disorder generating a Gaussian tail of states extending into the bandgap (Fig. 3a). Typical pi-stacks of conjugated polymers exhibit moderate amounts of paracrystalline...
  3. adil_mohammad

    Polymers that have spring properties similar to spring steel

    Hello everyone, First of all a very happy new year to everyone! And a big thank you to all the people who contribute to this forum, I have learned so much from here. I am prototyping a design for a part that will be used in a consumer product. I am in the early stages of researching...
  4. Stella Ch

    Industrial production of a drug host

    What's the best polymerisation method to manufacture a polymer drug host with high molecular weight? Is there a quick method to do so?
  5. Julijana Cvjetinovic

    Ways of joining two different polymers

    Hello everyone! I am currently working in the field of polymer composite materials.I was wondering what are all the possible ways to join two different polymers together? For example, Ultra-high-molecular-weight polyethylene (UHMWPE) and Polycaprolactone. I know that welding is process that...
  6. 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.
  7. T

    Melted cheese-like flow -- What is it called and its cause?

    There are some plastics I am using that when melted, pull apart in a stringy way. My best comparison is like melted cheese in a sandwich. I want to know more about this, but other than looking up 'polymer rheology', I'm not sure what I should call this type of flow. I want to know what causes...
  8. I

    Do amino-acids spontaneously bond within a cell?

    I was wondering whether it is possible for amino acids that end up in a cell (ready to be made into proteins) to spontaneously start to bond in the cytoplasm (or wherever the routing channel is I guess) and create randomly floating short strands of polymers? Furthermore, can it ever happen that...
  9. P

    Electroactive Polymers that expand under low voltages

    Hello internet! I understand the basic principle of EAPs (you apply a potential difference and it moves) but I can't for the life of me find any specific, named EAPs that fit my requirements. If possible could you tell me if you know of an EAP that: Works in a normal environment (air, room...
  10. J

    Is it possible to make a thermoplastic also photoactive?

    Could a polymer that acts like a photoresist (either positive or negative) also be a thermoplastic. Do you have any ideas on what polymer/mechanisms could be used to achieve this?
  11. S

    Relation between thermal expansion and density in Polymers

    Hello all, Is there any direct relation ship exists between the thermal expansion and density of polymer material (eg. PMMA, Teflon) ? Like, Lorentz- lorentz law relates directly the refractive index and density of the polymer. similarly any laws relating (thermal expansion and density of...
  12. T

    Flexible material that quickly dissolves in rubbing alcohol

    Hello! I'm looking for a substance that can: (1) be turned into a flexible material (e.g., a flexible plastic), (2) is dissolveable in rubbing alcohol but not water (or blood), and (3) safe for a medical procedure ... And, if possible, preferably biodegradable... I know that's kind of a...
  13. Y

    How Is the Volume Fraction of a Polymer Calculated in a Solution?

    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...
  14. G

    Designing Devices with Electroactive Polymer | Manufacturer Info

    I'm want to design a device that uses Electroactive polymer. Do you know design companies that have experience with Electroactive polymers? Do you know manufacturers of Electroactive polymers?
  15. J

    Polarization of polymers under electric field

    Hi, I'm thinking the following scenario. I have some solution in a container, where polymers are dissolved inside. If left so, the polymer will be homogeneous in the liquids. Now I add an electric field on the two sides of the container, will the polymers be polarized and stretched? So the...
  16. D

    Physics science fair on shoe polymers

    So I am doing a physics science fair project. My original idea was "How does heat affect friction in shoe polymers?" but how would I know how to identify shoe polymers and where would I get 5 or 6 different pairs of shoe polymers. I changed it to "How does different temperatures affect friction...
  17. M

    MSc Materials Science or MSc Advanced Composites & Polymers

    Would anyone here have an opinion on whether either of these MSc courses is better to have when looking for employment later? I'll already have a BSc Physics. 1) MSc Materials Science (at a much better ranked university than below, and includes some programming) 2) MSc Advanced Composites &...
  18. S

    I need to read about polymers

    I want to do research in polymers, and would like to build somewhat of a knowledge base before committing to a specific area. I'd like to spend 2 hrs/day just reading stuff and learning more about the field, and apply for Fall '15. I have some research experience from my undergrad, knows a good...
  19. Conservation

    Barium Titanate Sintered or in Polymers?

    Hello all, I know Barium Titanate is a common ceramic dielectric material. However, the methods of production seems to result in a powdered form of this substance, and most of the commercially available forms seem to be limited to powders of varying sizes from nanometers to micrometers; how...
  20. N

    Differences between the polymers Silicone 184 and Siloprene K1000?

    Hi, I was wondering if anyone knows if there is any differences between the polymers Silicone 184 and Siloprene K1000? I am to use this for layer application and gas diffusion. Kind regards,
  21. Y

    Elastic moduli of metals and polymers

    Why is there such a large difference between the elastic moduli of metals and polymers? Is it because of different bonding? Or something do with the structure? Thank you!
  22. T

    Surface alignment of P3HT and other conductive polymers

    Hi all, It is well known that poly(3-hexyl thiophene) and other conductive polymers with alkyl substituents align when deposited on a surface (e.g. by spin coating or drop casting). The common orientations for P3HT on silicon/silicon dioxide are "edge-on" in which the alkyl side-chains point...
  23. I

    Blending thermosensitive polymers with ph sensitive polymers for drug delivery

    i am interested in discussing about the pros and cons of having a vesicle of ph sensitive polymer (with drug to be delivered inside it), inside a vesicle of thermosensitive polymer for drug delivery. This gives us dual control capabilities that is temperature and ph based trigger...
  24. G

    Polymers pyrolisys - how it works?

    Hi, I was browsing the Internet and I found a thread about polymers pyrolysis: http://www.energeticforum.com/renewable-energy/7040-how-turn-plastic-waste-into-diesel-fuel-cheaply.html Guy there states, that just due to temperature of about 400C polymer chains are being broken into...
  25. R

    Can Molecular Structure Affect Impact Strength in Polymers?

    This is not a specific question. it's just common sense. all temp values in celsius. The impact values of polymers are definitely astonishing when i think at the molecular level it is said that increasing the molecular weight of the chains increase the impact strength. consider same...
  26. W

    Chemistry Finding mole fraction of polymers from weight percents %

    Watsup! I'm taking this nano class which is awesome but I am getting stuck on the gen chem material! no bueno. just want to make sure i did this right. Thanks! Homework Statement [/B] "A blend contains 45wt% polystyrene and 55wt% polypropylene. What is the mole fraction of polystyrene in the...
  27. C

    Pressure / temperature realtionship in polymers

    Hi, these is possibly a dumb question but... I know that with regards to gases: (P1*V1)/T1 = (P2*V2)/T2 However does this still apply to polymers in liquid state? In an injection moulding machine if I increase the pressure will you get an increase in temperature if the volume of...
  28. M

    Want to work in R&D in polymers

    Chemical engineering topics like heat transfer, transport, separations etc. never really appealed to me. But I really like research, and I think R&D is the place for me in industry. In order to work in R&D, I need an advanced degree. But I'm currently trying to decide what's the best way to get...
  29. D

    Substitution Polymers: Research, Explanation and Help Needed

    Hello, everyone. So, this is my first time doing Chemistry at school and today my teacher assigned each student a topic in Chemistry to research and give a short presentation on it on Monday. He assigned me the topic of, Substitution Polymers. So, tonight I thought I might do some research on...
  30. M

    Macro vs Nanoscale Pyroelectric Polymers

    So my question is this: Would Pyroelectric Effects become more pronounced if a polymer sheet was, instead of 1 cm thick, but rather, the thickness of a single polymer chain. For example, say the 1 cm thick pyroelectric polymer was heated. Since it is many chains thick, it would look something...
  31. T

    Conductivity of Conjugated Polymers: 1D or P Type?

    Hi! I have a question related to conductivity of conjugated polymers. I found that they could become conductive if they're dopped with any other element. Is it 1D conductivity because I read that electrons are not so mobile between the chains of polymers in a bulk, but they are along a polymer...
  32. A

    Structure and properties of polymers

    Hi! I need a reference (book, webpage) that explains how the structure of a polymer affects its properties. I've found plenty of material over how structure changes its mechanical properties, but I could not find how it changes other parameters (e.g. electrical conductivity, boiling point...)
  33. C

    Polymers - Crystallinity vs. Amorphousness

    I'm trying to get an understanding of what properties these two forms give a compound. I read that crystalline polymers are very strong but also very brittle whereas amorphous polymers are very tough meaning they can be bent and twisted but won't break. I then read that an example of a highly...
  34. C

    Viscosity of Polymers: Degree of Polymerisation & Molecular Weight

    In college we measured the viscosity of microcrystalline cellulose and used the result to determine its degree of polymerisation. Is the viscosity of a polymer directly proportional to its degree of polymerisation or something? In other words the bigger the polymer, the more viscous it is? Does...
  35. X

    Questions about polymers and their properties

    Homework Statement Hello everyone, I have a couple of question regarding polymers that I some trouble understanding and hoping you guys would point me into the right direction. For ''Thermosetting'' polymers I know that they become permanently hard with covalent bonds which they chain...
  36. E

    Biocompatible Non-Degradable Polymers

    Does anyone know of any polymers that are compatible/approved for use inside the body that don't degrade? I can find lots of information of biodegradable polymers, but my project involves ones that don't degrade, or if they do - very little. Thanks!
  37. R

    Henry's Law of Sorption in Rubbery Polymers

    Hi everyone, This is my first time posting here, so I apologize in advanced for not knowing the culture of this site. Please be patient, I will learn. :) I'm studying the sorption behaviors of gases in polymers and I have a question about sorption in rubbery polymers following Henry's...
  38. C

    Synthesis of polymers containing biarenes

    I am a high school chemistry AP student. In class, my teacher told us about how benzene's delocalized ∏ electrons can donate to a metal but it is not a strong bond. I wanted to know if it was possible to make a coordination compound that was also a polymer by using a biarene ligand, one end...
  39. I

    Partition function in polymers and entropic forces

    Hi all, Firstly, I'm not sure where to post this thread, but I'm hoping here is the right place. My questions developed through reading Verlinde's paper on entropic gravity: http://arxiv.org/abs/1001.0785" However my questions are with the introductory thermodynamic ideas he presents...
  40. C

    Mechanical Properties of polymers

    Hello everyone, I've had a hard time finding places where to look up the different mechanical properties of polymers. I am mainly interested in density, young's, bulk, and shear moduli. I would appreciate if anybody can point me out to some good resources. Thank you
  41. D

    Calculating the Molecular Weight of Glucose Polymers

    Glucose (C6H12O6) is a monomer that can form naturally occurring polymers. What would be the approximate molecular weight of a polymer made from 5 glucose monomers? a) 810 b) 828 c) 882 d) 900 i said D, but my friend in convincing me its B :S
  42. T

    A couple easy questions related to polymers

    1. HIPS is a : a)Polystyrene-Polybutadiene blend b)High Impact Polybutadiene Blend c)Polystyrene-Polybutadiene copolymer blended with polystyrene and polybutadiene d)High polystyrene matrix material I'm pretty sure it's not B, and I'm leaning towards C, but I'm not very confident...
  43. S

    Are All Polymers Hydrolysable?

    My book is talking about Condensation & Hydrolysis reactions & has said that Polymers are "digested" to become monomers in hydrolysis reactions, i.e. when water is added to a polymer. I just want to clarify, 1) Does adding water to all polymers break them apart instantly? i.e. are all...
  44. B

    Polymers with piezoelectric effect

    I am looking for a polymer that can be manipulated and that expands after applying pressure between the fingers, as a result of piezoelectric effect.
  45. S

    How do I set the lock in amplifier for photoconductivity through lab view?

    hi i am doing photoconductivity but i did not understand how to set the lock in amplifier for the photoconductivity through lab view.please help me out in doing pc
  46. M

    Need help with microshear bands in polymers

    This is my first post. I have a paper due on microshear banding in polymers. I have found lots of papers on the subject, but nowhere have I found a straightforward explanation of what is the underlying cause of these bands. What changes in structure are causing the bands, and what effects do...
  47. B

    Uncovering the Mystery of UV Degradation in Polymers

    Hey guys, just trying to get my head around this one.. Why do UV rays effect polymer chains so much? I understand that they weaken the bonds within the chains to create free radicals which then go on to react with other things which eventually makes the whole chain degrade as a whole, but...
  48. S

    Books for ceramics and polymers

    iam searching good books for ceramics please suggest some books actually i need details about the production techniques ,structural features,mechanical properties,industrial ceramics like tungestencarbide,silica-alumina,zirconia,sialons
  49. M

    Subliming, or evaporating polymers

    I have an application where I need to bond various materials together, perform certain machining, cutting, forming operations on this matrix - then - with the matrix in position, gradually heat & then drive off the polymer until only the metallic component remains in place. I had in mind a...
  50. M

    Cross-Linking Polymers & Slime Consistency

    [SOLVED] Cross-linking polymers Homework Statement What changes in consistency (if any) do you expect when adding more borax solution to your slime? Why? Homework Equations None The Attempt at a Solution Slime is a cross-linked polymer. Borax (borate ion) is the cross-link. So...