Addition polymer - wikipedia Addition polymer An addition polymer is a polymer that forms by simple linking of monomers without the co-generation of other products. Addition polymerization differs from condensation polymerization, which does cogenerate a product, usually water. Addition polymers can be formed by chain polymerization, when the polymer is formed by the sequential addition of monomer units to an active site in a chain reaction, or by polyaddition, when the polymer is formed by addition reactions between species of all degrees of polymerization. Addition polymers are formed by the addition of some simple monomer units repeatedly. Generally polymers are unsaturated compounds like alkenes, alkalines etc. The addition polymerization mainly takes place in free radical mechanism. The free radical mechanism of addition polymerization completed by three steps i.e Initiation of free radical, Chain propagation, Termination of chain. Contents 1 Polyolefins 1.1 Copolymers 2 Ring - opening polymerization 3 Further contrasts with condensation polymers 4 Biodegradation 5 History 6 References Polyolefins Many common addition polymers are formed from unsaturated monomers ( usually having a C = C double bond ). The most prevalent addition polymers are polyolefins, i.e. polymers derived by the conversion of olefins ( alkenes ) to long - chain alkanes. The stoichiometry is simple : n RCH = CH → ( RCH - CH ) This conversion can be induced by a variety of catalysts including free radicals, acids, carbanions and metal complexes. Examples of such polyolefins are polyethenes, polypropylene, PVC, Teflon, Buna rubbers, polyacrylates, polystyrene, and PCTFE. Copolymers When two or more types of monomers undergo addition polymerization, the resulting polymer is an addition copolymer. Saran wrap, formed from polymerization of vinyl chloride and vinylidene chloride, is an addition copolymer. Ring - opening polymerization Ring - opening polymerization is an additive process but tends to give condensation - like polymers but follows the stoichiometry of addition polymerization. For example, polyethylene glycol is formed by opening ethylene oxide rings : HOCH CH OH + n C H O → HO ( CH CH O ) H Nylon 6 ( developed to thwart the patent on nylon 6, 6 ) is produced by addition polymerization, but chemically resembles typical polyamides. Further contrasts with condensation polymers One universal distinction between polymerization types is development of molecular weight by the different modes of propagation. Addition polymers form high molecular weight chains rapidly, with much monomer remaining. Since addition polymerization has rapidly growing chains and free monomer as its reactants, and condensation polymerization occurs in step-wise fashion between monomers, dimers, and other smaller growing chains, the effect of a polymer molecule 's current size on a continuing reaction is profoundly different in these two cases. This has important effects on the distribution of molecular weights, or polydispersity, in the finished polymer. Biodegradation Addition polymers are generally chemically inert, involving strong C-C. For this reason they are non-biodegradable and difficult to recycle. In contrast, condensation polymers tend to be more readily bio-degradable because their backbones contain weaker bonds. History The first useful addition polymer was made by accident in 1933 by ICI chemists Reginald Gibson and Eric Fawcett. They were carrying out a series of experiments that involved reacting organic compounds under high temperatures and high pressures. They set up an experiment to react ethene with benzaldehyde in the hope of producing a ketone. They left the reaction vessel overnight, and the next morning they found a small amount of a white waxy solid. It was shown later that this solid was polyethylene. IUPAC definition Chain polymerization : Chain reaction in which the growth of a polymer chain proceeds exclusively by reaction ( s ) between monomer ( s ) and active site ( s ) on the polymer chain with regeneration of the active site ( s ) at the end of each growth step. The term `` addition polymerization '' is deprecated by IUPAC ( International Union of Pure and Applied Chemistry ) which recommends the alternative term chain polymerization. References Jump up ^ Introduction to Polymers 1987 R.J. Young Chapman & Hall ISBN 0 - 412 - 22170 - 5 Jump up ^ D. Margerison, G.C. East, J.E. Spice ( 1967 ). An Introduction to Polymer Chemistry. Pergamon Press. ISBN 978 - 0 - 08 - 011891 - 8. CS1 maint : Uses authors parameter ( link ) Jump up ^ `` Addition Polymers ''. Archived from the original on December 12, 2012. Retrieved July 17, 2012. Jump up ^ H. Stephen Stoker ( 1 January 2012 ). Organic and Biological Chemistry. Cengage Learning. p. 65. ISBN 978 - 1 - 133 - 10395 - 0. Retrieved 17 July 2012. Jump up ^ Penczek, Stanisław ; Moad, Graeme ( 2008 ). `` Glossary of terms related to kinetics, thermodynamics, and mechanisms of polymerization ( IUPAC Recommendations 2008 ) '' ( PDF ). Pure and Applied Chemistry. 80 ( 10 ) : 2163 -- 2193. doi : 10.1351 / pac200880102163. Paul J. Flory ( 1953 ). Principles of Polymer Chemistry. Cornell University Press. p. 51. ISBN 978 - 0 - 8014 - 0134 - 3. Retrieved 17 July 2012. Retrieved from `` https://en.wikipedia.org/w/index.php?title=Addition_polymer&oldid=856180207 '' Categories : Polymer chemistry Polymerization reactions Hidden categories : CS1 maint : Uses authors parameter Talk Contents About Wikipedia Čeština Deutsch Polski Português Slovenčina کوردی Edit links This page was last edited on 23 August 2018, at 12 : 12 ( UTC ). Text is available under the Creative Commons Attribution - ShareAlike License ; additional terms may apply. By using this site, you agree to the Terms of Use and Privacy Policy. Wikipedia ® is a registered trademark of the Wikimedia Foundation, Inc., a non-profit organization. About Wikipedia

Question: what kind of polymers are prepared by addition reactions of alkenes
Answer: polyolefins