To alleviate inconsistencies in these naming methods, adjusted definitions for condensation and addition polymers have been developed. A condensation polymer is defined as a polymer that involves elimination of small molecules during its synthesis, or contains functional groups as part of its [[backbone chain]], or it [[repeat unit]] does not contain all the atoms present in the hypothetical monomer to which it can be degraded.
== AdditionPolimérisasi polymerizationadisi ==
AdditionPolimérisasi polymerizationadisi involvesmajeujeutkeun thepegatna breakingbeungkeut ofganda doubleatawa orrangkep triple bondstilu, whichnu aredipaké usedpikeun tonyambungkeun linkmonomér-monomér monomerskana in to chainsranté. InDina thepolimérisasi polymerization of etheneéténa (figgbr. 1), itsbeungkeut pi-na bondpegat isbrokennu andsalajengna thesedua twoéléktronna electronsdisusun rearrangeulang topikeun createnyiptakeun a new propagating center like the one that attacked it. The form this propagating center takes depends on the specific type of addition mechanism. ThereAya aresababaraha severalmékanisme mechanismscara throughnaratasna which this can be initiated(inisiasi). TheMékanisme [[freeradikal radicalbébas]] mechanismngarupakeun wasmétode onenu ofpangmunggaranna thedipaké. firstRadikal methodsbébas tongarupakeun beatom/molekul used.nu Freeréaktif radicalspisan arenu verymibanda reactiveéléktron atomsnyorangan or(teu moleculesboga which have unpaired electronspasangan). TakingMisalna thedina polymerizationpolimérisasi of ethene as an exampleéténa, themékanisme freeradikal radicalbébas mechanismbisa candibagi bekana dividedtilu in to three stageshambalan: initiationinisiasi, propagationpropagasi, andjeung terminationterminasi.
InitiationInisiasi isnyaéta theprosés creationnyipta ofradikal freebébas radicalsnu necessarydipikabutuh forpikeun propagationpropagasi. TheRadikal radicalsbisa candijieun betina createdmolekul frompéroksida organicorganik, peroxidemolekul molecules,nu moleculesmibanda containingbeungkeut antunggal O-O single bond, byku reactingngaréaksikeun [[oxygenoxigén]] withjeung [[etheneéténa]]. TheHasilna mangrupa productsmolekul formednu areteu unstablestabil andnu easilygampang breakpisan downdibeulah intojadi twodua radicalsradikal. In an ethene monomer, one electron pair is held securely between the two carbons in a sigma bond. The other is more loosely held in a pi bond. The free radical uses one electron from the pi bond to form a more stable bond with the carbon atom. The other electron returns to the second carbon atom, turning the whole molecule in to another radical.
Propagation is the rapid reaction of this radicalised ethene molecule with another ethene monomer, and the subsequent repetition to create the repeating chain.
