Polymer synthesis and their uses

Plastics with rings in main branch tend to some stretchiness and these tend to tolerate impacts. Carbon chains wit single bonds are bendy but can become stiff and brittle like glass if they have side branches. Carbon chains with double bonds tend to behave more rubbery. 
Having oxygen in carbon chain adds strength under physical pressure but reduces tolerance to acids and sometimes also to UV light. Electronegativity could possibly cause both. Electron on carbons are relatively more attracted to oxygen which may add strength during hits. Hydrogen ions from acids are attracted to oxygen and can break this part up by leaving -OH group in broken tips. Best acid resistance seem to come from carbon only main chain with fluoride attached on sides like in Teflon or other fluorocarbons. Strength comes with ring structures in chains that add some stretchiness. Having carbon chain like in PET makes plastic capable of burning on its own while polymers with oxygen or nitrogen in main chain makes them less combustible or even self extinguishing when away from flame like fire doesn't get enough energy to keep flame going. Almost 100% carbon polymers also self extinguish when they have aromatic rings. Again this could be due to shock absorbing effect as fast plasma atoms can't easily hit out atoms due to collision energy transferred through soft material but with rigid molecular structure pieces could be struck out similar to hitting rubber compared to hitting concrete. Polymer behavior in large scale seems predictable if presumed that they behave like rubbery structure with such shape would behave.

Phthalates (R part can be semirandom structure which still leave it a phthalate) are common transparent additives that connect parallel polymer chains for extra durability, softness and flexibility although they can separate from plastics and if eaten they can interfere with hormone levels and fetal development.

Natural rubber latex has main cis-polyisoprene as main ingredient. Synthetic rubbers have often similar main chains with mixture of double and single bonds between carbon atoms. Double bonds are almost twice as hard to break as single bonds. Rubbers are usually strengthened with by heating it with sulfur to get sulfur cross-links (vulcanization).

Example of common synthetic rubber styrene-butadiene. About half of car tires are made from some variation of this rubber. Higher styrene (part with carbon ring) proportion creates harder material with less rubber like properties.

Neoprene is common soft rubber found in wetsuits, wire insulation, hoses and sound muffler. In foamed neoprene like in wetsuits it is made more heat preserving and bouncy by adding nitrogen gas to create many bubbles within rubber.  

Silicone polymers have main chain with alternating oxygen and silicon (PDMS has 2 methylgroups on sides). Unlike plastics they often tolerate temperatures of -100 to 250 degree Celsius while several plastics tend to break apart between 100-200 C (although some like aramide tolerate up to 500 C). Silicone lenses implanted after cataract surgery are stable enough to stay in eye for lifetime. PDMS is honey like oil that is sometimes used as food additive and doesn't have known serious toxic effects. In shampoos it makes hairs shiny and slippery.

Polyacrylic acid is charged polymer belonging to group of polyelectrolytes as every sidechain is charged in water and attracted to water. This makes it good absorber of water and it is used in some diapers.  

Bakelite was one of the first invented polymer that was used for hard non-conductive parts that tolerate heat from electronics. It is one of the plastics that can't be remolded or reused by heating.

Polyethylene (PET) is most commonly found plastic in form of plastic bags and bottles. Main chain can look similar to fatty molecules or paraffin but in PET these chains are cross-linked together so much that bacteria or larger organisms can't digest it. It tolerates strong acidic and alkaline substances. Organic solvents can dissolve it if it isn't cross-linked enough. After igniting it burns independently similarly to many other substances made only from carbon and hydrogen. 

PBT is nonconductive polymer that can also be used as fibers in toothbrushes but it degrades with UV light.

Fluorosurfactants are molecules where hydrogen atoms around carbon chains get replace by fluoride and that can give water repelling effect but they also keep dirt from sticking due to overall non-sticky properties.

PTFE (brand name Teflon) is one of many fluorosurfactants and like other fluoride containing substances it is very slippery which is used in cooking to avoid sticking and in machines to reduce friction. Strong attraction between C and F due to large electronegativity difference makes them resistant to acids and heat. 

Polyimides are polymers of imide (structure left) which are usually cross-linked together by flexible 4,4'-oxydianiline (structure right). They are durably flexible plastics used in wires that connect laptop screen to motherboard and are bent every time screen is moved. They are relatively heat resistant tolerating over 200 C and are sometimes used in flame retardant clothing in addition to wires that may need to work in hot environment like near hot computer parts or inside chips themselves. One use of needle-like polyimides is in hot factory chimneys filtering out larger dust. It is resistant to weak acids but not to strongly alkaline or acidic substances.

Polyoxymethylene (POM) is very stiff and hard plastic up to around 40 C and melts around 170 C depending on polymer structure. It is very relatively slippery compared to rubbery or softer polymers.
It is used in insulation, zippers, aerosol cans, chains, springs and screws in case strength/stiffness of metals is not required.

Polystyrene is common rigid and relatively fragile packaging (in soft foamy form or hard cd cover or in plastic utensils) material that dissolves in acetone but is slowly biodegradable.

Polymethylpentene is transarent plastic with maybe most consistent refractive index for wide range of EM wavelengths which could make it good lens that directs many wavelengths in same directions. 

PMMA (Poly(methyl methacrylate)) is also shortened as acrylic glass. It's one of the hardest polymers used in bullet resistant glass and in windows of submarines reaching 10+ km below surface. During World War it was used in submarine periscopes and plane turret windows. Police cars tend to have glass made from it and so are their transparent riot shields. PMMA can be implanted within body and it is used as artificial lens after people noticed pilots who got eye injuries with PMMA shards during II WW didn't get much immune reactions around PMMA shards. PMMA has also been used for connecting artificial skeletal parts to bones (commonly in hip replacement) although it seems less safe when it is solidified as it can heat to over 80 C during polymerization at surgery and unpolymerized MMA itself is irritant and possible carcinogen.
Bullet resistant glasses usually have several layers of acrylic. If acrylic is used to flatten bullet in one layer and other stretchier polycarbonate layer absorbs energy then it can create one way bullet resistant glass (example clip) which passes bullet when shot from polycarbonate side but not from PMMA side. Polycarbonate is about as durable as PMMA but can change shape more without cracking but it doesn't stop bullets if they aren't flattened enough.
CD's and DVD's use both PMMA and polycarbonate. Common weakness of PMMA seems to be sensitivity to acids.
Plastic optical fibers often use acrylic and polystyrene as transparent core and some other material around it.

Polycarbonate structure. It is transparent and strong plastic used in plastic bottles in addition to bullet resistant glasses.

It is produced from bisphenol A and phosgene which can be released if polycarbonate gets hot and/or touches water and it has many effects on hormones and neurotransmitter pathways along with possibly increased risk of cancer so hot water in plastic bottles is probably not good.

Aramid (brand name Kevlar) is soft bullet resistant material which is also found in bike tires. Electrostatic attractions between parallel fibers hold it together (and probably reconnect similarly if strong force pulls them apart while rings are probably small scale stretchy shock absorbers). Aramide was probably used in this clip (shot shown around 9th minute) where soft jacket type armor stopped bullet shot at interviewer (founder and CEO of company said workers who make those also get shot as part of job). While aramide vests can look thick and stiff they can also look like usual soft, semitransparent and thin clothing. It doesn't melt and degradation starts from 500 C. It's nonconductive (could build up static electricity) and degrades with UV light, salts and acids. 

Nylon 6 is made of caprolactam which has 6 carbons. Polymerization happens in nitrogen atmosphere at 533 K degrees. Durability and softness make it usable for toothbrush hairs, string for musical instruments and non-absorbable surgical sutures.

Acrylonitrile, butadiene and styrene (ABS) is mixture of these 3 monomers that create strong hard plastics that are used in Lego pieces and hard plastic safety helmets. Proportions of monomers can vary widely. Polar nitrile groups bind polymer chains due to electrostatic forces. Styrene gives shiny appearance. Butadiene is rubbery substance and it adds similar bendy strength to ABS. Molding at higher temperature adds gloss and heat resistance but molding at lower temperature adds impact resistance strength. Adding glass fibers can add strength. ABS is common material in 3D printers.

Polyvinyl acetate is used in PVA glue as adhesive. 

Structure of cyanoacrylate in superglues is similar to acrylic glass but where one methyl group is switched with cyanide group. It polymerizes in presence of -OH group in water so it can be used underwater.

Polyvinyl butyral is plastic used in laminated glass in car windshields where it keeps shattered glass shards from separating from glass.

Maneb is widely toxic polymeric fungicide that is not easily available as it is suspected to be damaging enough to dopamine cells to cause Parkinson's disease.

Polyacrylonitrile is common precursor for carbon fibers. It turns into carbon fiber if heated above 1000 degrees in inert (no oxygen or other reactive gases) atmosphere so carbon could stay solid at that temperature.

Polylysine is made of essential amino acid lysine. It looks yellow and has mild bitter taste. As polymer it has use as food preservative. It seems to work by electrostatically binding with bacterial outer membrane and breaking it apart.

Nafion is one semipermeable membrane that can be used in hydrogen fuel cells as it let's protons and oxygen pass but not oxygen or other negatively charged particles (fluoride is negatively charged and fluoride tends to create tightly packed materials (due to being relatively small element) which are good at blocking fluids and gases out). Proton exhange membrane is overall name to polymers that can be used for membranes that let protons through if under water but not hydrogen, oxygen or negatively charged particles.

Medically used polymers

Polyethylene glycol shows diverse effects that can have medical usefulness. It's monomer ethylene glycol itself is poisonous to kidneys if it reaches bloodstream for example by touching wound plus it may form dioxanes that damage brain and other organs and cause cancers in long term unless removed from polymer. On other hand polymer itself is used as laxative by attracting water and through osmosis it could cause water pressure of 10 atmospheres. Expreriments that are not confirmed on humans: In animal testing it seemed to reduce colorectal cancer. If injected it seems to help motor nerves heal after injury in test animals. It seems most effective substance to avoid chemically caused cancers in rats.  

Dextranomer is made of dextran and it is used to speed up wound closing and to avoid fecal incontinence. 

Polyaminopropyl biguanide is disinfectant for contact lenses, skin and wounds.

Policresulen is antiseptic that can stop bleeding.

Polymeric motors

Several polymers with different conductivities mentioned here including Nafion (from hydrogen cells) can work as polymeric motors that can change shape even with 1 volt current. For example flat Nafion with conductive gold or platinum particles can use 1-5 volts to change shape. Mechanical force on material can cause proportional voltage difference so they also work as pressure sensors. Voltage of more than 1,23 volts can break water into explosive mixture of hydrogen and oxygen gas.

Example of polymers bending with involvements of electrolytes. EAP (electroactive polymers) is general name to polymers that can be used in polymeric motors. Electric fields push ions in to one side of polymer causing them to swell at that side and bend material. There are other ways polymers move like changing electric field alignment in ferroelectric substances or simple piezoelectric response that every material shows but type shown above seemed to be most effective with lowest needed voltage.  

Biodegradable polymers

Polymers that degrade in nature are usually held together by same peptidic bond that connect proteins or resemble polysaccharides so bacteria that can use proteins (all of them) or polysaccharides (whoever digest starch, cellulose and chitin) could possibly break apart these plastics.

Polyactic acid (PLA) is biodegradable polymer that is made of lactic acid and lactide which is basically 2 lactic acid molecule joined together into circle. As PLA degrades it turns back into safe enough lactic acid. PLA is used in medical pins, screws and meshes which break apart in human body within 0,5-2 years depending on type.

Polyaspartic acid is basically large protein made of repeating aspartic acid isomers which makes it easy to digest for bacteria. It can function as swelling water absorber in diapers and feminine products. Natural proteins have alfa version of these connections. Polymerization seems easy enough to do at home. First aspartic acid gets heated to turn it into succinimide rings. Then NaOH gets added to break those rings partially creating polymer with random distribution of alfa (30%) and beta (70%) linkages.

"Self-healing" polymers

Self healing of simple acrylic glass can happen if broken tips have spare unbound electron (usually shown as dot on illustrations) that could easily grab other unbound electron from other tip. In case it crack it couldn't self heal those cracks but acrylic is one of the plastics that soften with heating and can be remolded again.

If broken tips have opposite charges then they'd attract and use their unbound electrons to reconnect.

One common self-healing event is Diels-Alder reaction shown above. Those 2 joining parts can be part in already round carbon circle or other structure as long part of it look like parts shown above. Not all atoms in rings need to be carbon but existence of double bonds in this configuration seems to be requirement. 

One example of Diels-Alder reaction creating crosslinks between 2 strands of polymer. Heating it to 80 C for over 2 hours breaks these chemical bonds and makes material softer for rechanging shape before cooling.

Polymer branches that have sulfur containing tips can connect with other such tips and create sulfur bridges. Sulfur is also common in proteins in cysteine that forms similar bridges and stabilizes proteins in higher temperatures and rubber vulcanization creates similar connections.

Background chemistry

Many polymers are made of monomers that had double bonds but which are not in polymer with some B group metal catalyst causing polymerization.
Double bonds are attracted to positive charge due to double or triple bonds having 4 or 6 electrons between 2 atoms with relatively short distance between atoms while electron density in multiple bond is relatively high. By having something positively charged together with at least double bonded monomers tends to start joining of these molecules as positively charged B group metals are attracted mostly to double or triple bonds which have more negatively charged electrons. At least B group metals tend to have many electrons that could be easily lost to other atoms (in conduction band) so they may interact shortly but then separate due to easily lost electrons and atoms that are left with spare electrons use it to connect with almost any available atom but preferably with atom that also has spare electron. This ease of losing electrons makes B group metals good catalysts that can react many times over with different substances without losing effectiveness. Usually these catalysts are in form of some metal salt where negatively charged additives make metal atom more likely to have positive charge without needing solvent to give metal its charge.

Sometimes chemists need uncharged solvents to not interfere with chemical reactions based on electric attractions but which still need solvent to move molecules around so they could meet more thoroughly like with methamphetamine production where charged pseudoephedrine, iodine and lithium (different substances could work) are mixed in uncharged (but explosive and unhealthy) benzene or lighter fluid. I've checked many drug synthesis recipes and organic solvents from slightly charged alcohols to uncharged benzene and toluene seem needed in every step where differently charged atoms need to combine. 

Electron bond type on stiffness


Single bond leaves room to flexibility as atoms can swivel more. 

Double bonds add rigidity to plastics, rubbers and also to fatty acids so unsaturated (have double bonds) fatty acid are more rigid. Such atty acids stay at same angle through wide temperature range. Addition of hydrogen saturates fatty chain and helps with bending. If hydrogen atoms around these double bond area are on same side of chain (cis configuration), then molecule gets curve at this place but with trans configuration hydrogen atoms are on opposite sides and double bond area stays straight. This bent shape of cis fatty acid makes them harder to be packed tightly so it takes less heat to keep it fluid so they are likely fluid in body. Trans fatty acids are straight and that makes it easy for them to be tightly together which can increase their melting point higher than body temperature so they could also stay solid inside humans and that makes trans fats less healthy.
Hydrogenation would add hydrogen onto carbon atoms in double bonds and make them saturated acids which themselves are relatively unhealthy. Hydrogenation can happen in high pressure (~14 atmosphere) and ~140-170 Celsius.

Peptide bonds 

Probably most common polymers are proteins which are connected together by peptide bonds where positively and negatively charged areas connect. Possible that enzymes that connect molecules have some uncharged amino acids around it so electric attraction would be fine.
Some chemical reactions need pressure like 10-100 atmospheres. In these cases weight of people is enough to start chemical reactions by forcing atoms together. Proteins have varying inner pressure as their uncharged parts try to stay in middle (where chemical reactions tend to happen) away from water and charged areas near surface attracted to each other may tighten together adding pressure to middle of enzyme that probably can't be calculated with current knowledge.

Pressure in enzymes could be presumed from biochemical reactions. Possible example of high pressure in proteins would be in reactions where nitrogen becomes ammonia in bacteria that often live in roots of plants. Industries produce ammonia at 200 atmospheric pressure with iron (available in cells) and high heat (fast or strong collisions could imitate effect of heat).
Possible that proteins could achieve that type of pressure in some parts in them especially if protein is very large with many charged parts trying to electrostaticly contracts protein tighter together. Also ATP or some other energetic organic substance is commonly needed for cells to build larger molecules and when ATP releases phosphate which could give larger molecule sudden jolt that could increase pressure momentarily even more. Similar high pressure in enzymes applied unevenly could potentially break them apart in proteins that break things apart.

Computer parts made from polymers

Polymers can be used almost any computer part from screens, (temperature, PH, pressure, electric field, light, infrared, radio wave and probably also radioactivity) sensors, simple CPU's and memory storage devices.

Above shown polymeric computer (mentioned at latest in 2011)  has 8 bit processor with 4000 transistors on plastic film. Processor has 2 layers each 25 micrometers thick. One layer is does arithmetic calculations with 3381 transistors and other layer is memory with 612 transistors for instructions. Semiconductive ingredient was small molecule pentacene. It needs 10-20 volts and works at up to 6 hertz frequency with power consumption of 0,1 milliwatts at 10 volts. While they are maybe weakest computers done recently they have potential for use as disposable cheap addition to packaging and they can do simple math on screens that could be printed on similar material.



Stable memories can be made from ferroelectric polymers that can be used for that role by preserving electric polarity like ferromagentic substances preserve magnetic pole directions.
Organic computer memories can be made with flurocarbon type substances. Their structure can look bit like teflon but with fewer fluoride atoms.

Example of ferroelectric polyvinylidene fluoride. Fluoride part is the negatively charged part and it has to be below its curie temperature to preserve where charges are directed. This substance can also detect pressures and heat. 1 newton of pressure seems to create charge comparable to charge of ~40 million electrons (6-7 picocoulomb per newton) which at least at the time of that experiment was at least 10 tmes more than other polymers could create. To get this pressure sensitive response its electric polarity had to be first oriented by electric field of 30 000 volts per millimeter of thickness (or 30 volts per micrometer or 0,03 volts per nanometer if polymer sheet was thin enough and electrodes were that close). Thinner ones have been used in some thermal cameras. This polymer is insulating enough to be used in wire insulation. Flowing electrons would probably get captured by fluoride atoms.

Polyaniline is semiconductive polymer. It can change colors depending on oxidation state or by doping with acids or bases.

It can be in 3 different forms under different names but similar structures. Each of 3 has different appearance and polyaniline is usually mixture of these 3 states. Emeraldine with acid is green and ~10 million times more conductive than without acid. With bases emeraldine looks blue. Leucoemeraldine is white or transparent. Pernigraniline is blue/violet and most oxidized among 3. Electricity can change them from one form to other and change colors with that which can be useful in window coating that can go from transparent to colored.
Industrially polyaniline has advantage of being maybe cheapest conductive polymer and it can be used as color changing acid or base sensor which could be cheaply replaced. Such materials can dissipate static electricity and to some extent block electric fields for which they have been commonly used in electronics to avoid static electricity buildup. They may have uses as polymeric motors.

Inkjet printers have been used to add organic LED light sources on polymers. Printers could potentially be used to print different transistors and conductive materials as well.

Polyphenylene vinylene was the first known polymer that could emit light and be used as organic LED. It can work as organic solar cell but it degrades with light and oxygen.

While polymers are relatively inefficient at producing light they can be mixed with almost 100% efficient non-polymeric small molecules that have organoiridium compounds like Ir(mppy)3 above so polymers themselves could be bendy transparent electrodes to main light source.

Polyfluorene are conductive polymers that can emit light through entire visible light spectrum although they tend to create green when middle ring get ketone groups.

Light frequency goes redder if alkoxy (including ether bonds) get replaced by alcohol groups. It seems wavelength increases towards red as more groups get added that could transfer protons like hydrogen in alcohol group to nitrogen compared to uncharged methane or other carbohydrate which themselves could reduce wavelength and get closer to blue colors. Such polymers need orderly sequence of monomers. Polymer made only from polyfluorene is blue. By adding substances that emit lower energy photons polyfluorene can work as initial light source that stimulates others if they are much closer than wavelength (possibly below 5 nm as doubling distance may weaken transmitted energy million times). If those additives absorb photon energy then emit lower energy photon that is common to them. If middle 5 carbon ring in polyfluorene has larger aromatic oxygen containing groups like alkoxyphenyl in position R1 or R2 then it becomes stabler at emitting blue light compared to just carbohydrate groups in these positions. When using polyfluorenes in solar cells their efficiency can be increased in their conjugated (alternating single and multiple bonds along chain) side chains have some electronegative atom in ends.