background preloader

Polymers

Facebook Twitter

Plastipedia: Plastics Processes. Login Join the BPF Join the BPF Mailing List Related Categories Plastipedia Plastics Processes Content 1) Processing Thermoplastics1.1 Blown Film1.2 Extrusion Blow Moulding1.3 Extrusion Profiles & Sheet1.4 Injection Blow Moulding1.5 Injection Moulding1.6 Injection Moulding (Gas Assisted)1.7 Injection Stretch Blow Moulding1.8 Insert Moulding1.9 Machining of Plastics1.10 Moulding Expanded Polypropylene (EPP)1.11 Moulding Expanded Polystyrene (EPS)1.12 Process Cooling1.13 Rotational Moulding1.14 Structural Foam1.15 Thermoforming1.16 Vacuum Forming1.17 Other Extrusion Processes.

Plastipedia: Plastics Processes

Vinyl chloride. Vinyl chloride is an organochloride with the formula H2C=CHCl that is also called vinyl chloride monomer, VCM or chloroethene.

Vinyl chloride

This colorless compound is an important industrial chemical chiefly used to produce the polymer polyvinyl chloride (PVC).[1] About 13 billion kilograms are produced annually. VCM is among the top twenty largest petrochemicals (petroleum-derived chemicals) in world production. The United States currently remains the largest VCM manufacturing region because of its low-production-cost position in chlorine and ethylene raw materials. China is also a large manufacturer and one of the largest consumers of VCM.[2] Vinyl chloride is a gas with a sweet odor.

It is highly toxic, flammable, and carcinogenic. Production[edit] Polyvinyl chloride. Poly(vinyl chloride), commonly abbreviated PVC, is the third-most widely produced polymer, after polyethylene and polypropylene.[4] PVC is used in construction because it is more effective than traditional materials such as copper, iron or wood in pipe and profile applications.

Polyvinyl chloride

It can be made softer and more flexible by the addition of plasticizers, the most widely used being phthalates. In this form, it is also used in plumbing, electrical cable insulation, inflatable products and many applications where it replaces rubber.[5] Polypropylene. Polypropylene (PP), also known as polypropene, is a thermoplastic polymer used in a wide variety of applications including packaging and labeling, textiles (e.g., ropes, thermal underwear and carpets), stationery, plastic parts and reusable containers of various types, laboratory equipment, loudspeakers, automotive components, and polymer banknotes.

Polypropylene

An addition polymer made from the monomer propylene, it is rugged and unusually resistant to many chemical solvents, bases and acids. In 2008, the global market for polypropylene had a volume of 45.1 million metric tons, which led to a turnover of about $65 billion (~ €47.4 billion).[1] Chemical and physical properties[edit] Degradation[edit] Polypropylene is liable to chain degradation from exposure to heat and UV radiation such as that present in sunlight.

History[edit]

Pol pathways

Coal tar. Applications[edit] Pavement sealcoat[edit] Coal tar is incorporated into some parking-lot sealcoat products, which are used to protect and beautify the underlying pavement.[2] Sealcoat products that are coal-tar based typically contain 20 to 35 percent coal-tar pitch.[2] Substantial concerns have been raised about the safety of this application of coal tar, given that coal tar is known to cause cancer in humans and that several PAH compounds in coal tar are toxic to aquatic life.[3]

Coal tar

Naphthalene. Naphthalene is an organic compound with formula C 10H 8.

Like benzene, naphthalene can undergo electrophilic aromatic substitution. For many electrophilic aromatic substitution reactions, naphthalene reacts under milder conditions than does benzene. For example, whereas both benzene and naphthalene react with chlorine in the presence of a ferric chloride or aluminium chloride catalyst, naphthalene and chlorine can react to form 1-chloronaphthalene even without a catalyst. Likewise, whereas both benzene and naphthalene can be alkylated using Friedel-Crafts reactions, naphthalene can also be alkylated by reaction with alkenes or alcohols, with sulfuric or phosphoric acid as the catalyst. – simo88

It is the simplest polycyclic aromatic hydrocarbon, and is a white crystalline solid with a characteristic odor that is detectable at concentrations as low as 0.08 ppm by mass.[1] As an aromatic hydrocarbon, naphthalene's structure consists of a fused pair of benzene rings.

Naphthalene

It is best known as the main ingredient of traditional mothballs. History[edit] Structure and reactivity[edit] Phthalic anhydride. Phthalic anhydride is the organic compound with the formula C6H4(CO)2O.

Phthalic anhydride

It is the anhydride of phthalic acid. Phthalic anhydride is a principal commercial form of phthalic acid. It was the first anhydride of a dicarboxylic acid to be used commercially. This colourless solid is an important industrial chemical, especially for the large-scale production of plasticizers for plastics. In 2000, the world wide production volume was estimated to be about 3M tonnes per year.[1] Synthesis and production[edit] Phthalic acid. Phthalic acid is an aromatic dicarboxylic acid, with formula C6H4(CO2H)2.

Phthalic acid

It is an isomer of isophthalic acid and terephthalic acid. Although phthalic acid is of modest commercial importance, the closely related derivative phthalic anhydride is a commodity chemical produced on a large scale.[5] Production[edit] Phthalic acid is produced by the catalytic oxidation of naphthalene directly to phthalic anhydride and a subsequent hydrolysis of the anhydride.[5] Terephthalic acid. Terephthalic acid is the organic compound with formula C6H4(COOH)2.

Terephthalic acid

This colourless solid is a commodity chemical, used principally as a precursor to the polyester PET, used to make clothing and plastic bottles. Several million tonnes are produced annually. History[edit] The importance of the terephthalic acid was realized after World War II. Plasticizer. For plastics[edit] Plasticizers for plastics are additives, most commonly phthalate esters in PVC applications.

Plasticizer

Almost 90% of the market for plasticizer is for PVC, giving this material improved flexibility and durability.[1] The majority is used in films and cables.[2] Plasticizers work by embedding themselves between the chains of polymers, spacing them apart (increasing the "free volume"), and thus significantly lowering the glass transition temperature for the plastic and making it softer.

For plastics such as PVC, the more plasticizer added, the lower its cold flex temperature will be. Petroleum. An oil refinery in Mina-Al-Ahmadi, Kuwait The use of fossil fuels such as petroleum has a negative impact on Earth's biosphere, releasing pollutants and greenhouse gases into the air and damaging ecosystems through events such as oil spills. Concern over the depletion of the earth's finite reserves of oil, and the effect this would have on a society dependent on it, is a concept known as peak oil.

Etymology[edit] The word petroleum comes from Greek: πέτρα (petra) for rocks and Greek: ἔλαιον (elaion) for oil. History[edit] Early history[edit] Petroleum, in one form or another, has been used since ancient times, and is now important across society, including in economy, politics and technology. Modern history[edit] Naphtha.

General polymerisation and methods

Viscoelastic Phase Separation in Epoxy/Thermoplastic Blends. Thermosetting resins are usually low molecular weight monomers or oligomers having functional groups for cross-linking reaction. Transesterification. Polyester. SEM picture of a bend in a high-surface area polyesterfiber with a seven-lobed cross section Close-up of a polyester shirt Polyester is a category of polymers which contain the ester functional group in their main chain. Although there are many polyesters, the term "polyester" as a specific material most commonly refers to polyethylene terephthalate (PET).

Polymer theory

Exotic discovery made in soft polymer. Professor Frank S.

Bates and his team stumbled upon the completely new material quite by accident. "My students were exploring the mechanical properties of polymers made from poly(lactide)--a derivative of corn--and poly(isoprene)--a synthetic form of natural rubber," Bates said. "They discovered a new and unexplainable x-ray scattering pattern." The unusual pattern turned out to be associated with a long-predicted crystal structure, now known as the Frank-Kasper sigma phase. – simo88
The interesting thing about block copolymers is that they can spontaneously self-assemble into tiny nanoscale structures, including spheres, when cooled. The spheres form because the different blocks, though chemically connected, repel each other like oil and vinegar. To overcome this self-revulsion, the material organizes itself so that a core of one type of block circles in on itself, leaving a "halo" of the second type of block hanging out like a hairy fringe. – simo88

Bates and his research team at the University of Minnesota in Minneapolis have discovered an unusual type of soft material that was conceived of over 50 years ago, but has never before been found in a plastic--although it has been seen in stainless steel and other metal alloys. Scientists and engineers create the 'perfect plastic' (10/7/2011) Researchers at the University of Leeds and Durham University have solved a long-standing problem that could revolutionize the way new plastics are developed.

The mathematical models used put together two pieces of computer code. The first predicts how polymers will flow based on the connections between the string-like molecules they are made from. A second piece of code predicts the shapes that these molecules will take when they are created at a chemical level. These models were enhanced by experiments on carefully synthesised 'perfect polymers' created in labs of the Microscale Polymer Processing project. – simo88

Solving a tangled polymer problem. New elastic material changes color in UV light. Researchers from North Carolina State University have created a range of soft, elastic gels that change color when exposed to ultraviolet (UV) light -- and change back when the UV light is removed or the material is heated up.

The gels are impregnated with a type of photochromic compound called spiropyran. Spiropyrans change color when exposed to UV light, and the color they change into depends on the chemical environment surrounding the material. – simo88

Frameset Page.

"green" polymers

Polyhydroxyalkanoates. Polymer. Polymer Physics. Polymer. IUPAC definition Substance composed of macromolecules. Note: Applicable to substance macromolecular in nature like cross-linked systems that can be considered as one macromolecule. The term "polymer" derives from the ancient Greek word πολύς (polus, meaning "many, much") and μέρος (meros, meaning "parts"), and refers to a molecule whose structure is composed of multiple repeating units, from which originates a characteristic of high relative molecular mass and attendant properties.[6] The units composing polymers derive, actually or conceptually, from molecules of low relative molecular mass.[7] The term was coined in 1833 by Jöns Jacob Berzelius, though with a definition distinct from the modern IUPAC definition.[8][9] 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.[10] Common examples[edit]

The Plastics Historical Society - What are Plastics? The Early Years Of Artificial Fibres. Plastipedia: The Plastics Encyclopedia - A History of Plastics. The Plastics Historical Society - People & Polymers. Tougher, lighter wind turbine blade developed: Polyurethane reinforced with carbon nanotubes. Efforts to build larger wind turbines able to capture more energy from the air are stymied by the weight of blades.

The heavier the blades, the more wind is needed to turn the rotor. That means less energy is captured. And the more the blades flex in the wind, the more they lose the optimal shape for catching moving air, so, even less energy is captured. – simo88

Polymer batteries for next-generation electronics.