- Polymer chemistry
Polymer chemistry or macromolecular chemistry is a multidisciplinary
science that deals with thechemical synthesis and chemical properties ofpolymer s ormacromolecule s. According toIUPAC recommendations [IUPAC definition [http://www.iupac.org/reports/1996/6812jenkins/substances.html#2.2IUPAC Polymer] ] [IUPAC definition [http://www.iupac.org/reports/1996/6812jenkins/molecules.html#1.1 Macromolecule] ] , macromolecules refer to the individual molecular chains and are the domain ofchemistry . Polymers describe the bulk properties of polymer materials and belong to the field ofpolymer physics as a subfield ofphysics .*
Biopolymer s produced by living organisms:
**structuralprotein s:collagen ,keratin ,elastin …
**chemically functional proteins:enzyme s,hormone s,transport protein s…
**structuralpolysaccharide s:cellulose ,chitin …
**storage polysaccharides:starch ,glycogen …
**nucleic acid s:DNA ,RNA
*Synthetic polymers used forplastic s —fiber s,paint s,building material s,furniture , mechanical parts,adhesive s:
**thermoplastic s:polyethylene ,Teflon polystyrene ,polypropylene ,polyester ,polyurethane ,polymethyl methacrylate ,polyvinyl chloride ,nylon ,rayon ,celluloid ,silicone ,fiberglass …
**thermosetting plastic s: vulcanizedrubber ,Bakelite ,Kevlar ,epoxy …Polymers form by
polymerization ofmonomer s. A polymer is chemically described by itsdegree of polymerisation ,molar mass distribution ,tacticity ,copolymer distribution, the degree of branching, by itsend-group s, crosslinks,crystallinity and thermal properties such as itsglass transition temperature and melting temperature. Polymers insolution have special characteristics with respect tosolubility ,viscosity and gelation.History
The work of
Henri Braconnot in 1777 andChristian Schönbein in 1846 led to the discovery ofnitrocellulose , which, when treated withcamphor producedcelluloid . Dissolved inether oracetone , it iscollodion , used as awound dressing since the U.S. Civil War.Cellulose acetate was first prepared in 1865. In 1834,Friedrich Ludersdorf andNathaniel Hayward independently discovered that adding sulfur to raw naturalrubber (polyisoprene) helped prevent the material from becoming sticky. In 1844Charles Goodyear received a U.S. patent for vulcanizing rubber withsulfur and heat.Thomas Hancock had received a patent for the same process in the UK the year before.In 1884
Hilaire de Chardonnet started the first artificialfiber plant based on regeneratedcellulose , orviscose rayon , as a substitute forsilk , but it was very flammable. [ [http://www.plastiquarian.com/top.htm plastiquarian] ] In 1907Leo Baekeland invented the first synthetic polymer, athermoset tingphenol -formaldehyde resin calledBakelite .Cellophane was invented in 1908 byJocques Brandenberger who squirted sheets of viscose rayon into anacid bath. [ [http://inventors.about.com/library/inventors/blcellophane.htm inventors of blcellophane] ] In 1922Hermann Staudinger was the first to propose that polymers consisted of long chains ofatoms held together bycovalent bond s. He also proposed to name these compoundsmacromolecule s. Before that,scientist s believed that polymers were clusters of smallmolecule s (calledcolloid s), without definite molecular weights, held together by an unknownforce . Staudinger received theNobel Prize in Chemistry in 1953.Wallace Carothers invented the first synthetic rubber calledneoprene in 1931, the firstpolyester , and went on to inventnylon , a true silk replacement, in 1935.Paul Flory was awarded theNobel Prize in Chemistry in 1974 for his work on polymerrandom coil configurations in solution in the 1950s.Stephanie Kwolek developed anaramid , oraromatic nylon namedKevlar , patented in 1966.There are now a large number of commercial polymers, including
composite material s such ascarbon fiber -epoxy ,polystyrene -polybutadiene (HIPS),acrylonitrile -butadiene -styrene (ABS), and other such materials that combine the best properties of their various components, including polymers designed to work at hightemperature s inautomobile engine s.ee also
*
Radical polymerization
*RAFT (chemistry)
*Robert GilbertReferences
External links
* [http://www.polymerchemistryhypertext.com/ Polymer Chemistry Hypertext, Educational resource]
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