Kuwanikwa kwe polyurethane [PU] kunotanga mugore ra1937 naOtto Bayer nevamwe vake vaaishanda navo kumarabhoritari eIG Farben muLeverkusen, Germany.Iwo ekutanga mabasa akanangana nePU zvigadzirwa zvakawanikwa kubva kune aliphatic diisocyanate uye diamine inogadzira polyurea, kusvika zvinofadza zvimiro zvePU zvakawanikwa kubva kune aliphatic diisocyanate uye glycol, zvaonekwa.Polyisocyanates yakatanga kuwanikwa mukutengesa mugore ra1952, nguva pfupi yadarika kugadzirwa kwePU kwakapupurirwa (mushure meHondo Yenyika II) kubva ku toluene diisocyanate (TDI) uye polyester polyols.Mumakore akatevera (1952-1954), masisitimu epolyester-polyisocyanate akasiyana akagadzirwa neBayer.
Polyester polyols zvishoma nezvishoma akatsiviwa nepolyether polyols nekuda kwezvakanaka zvawo zvakati wandei senge mutengo wakaderera, nyore kubata, uye yakagadziridzwa hydrolytic kugadzikana pane yekutanga.Poly(tetramethylene ether) glycol (PTMG), yakaunzwa neDuPont muna 1956 ne polymerizing tetrahydrofuran, seyekutanga kutengeswa polyether polyol.Gare gare, muna 1957, BASF neDow Chemical vakagadzira polyalkylene glycols.Kubva paPTMG uye 4,4'-diphenylmethane diisocyanate (MDI), uye ethylene diamine, Spandex fiber inonzi Lycra yakagadzirwa naDupont.Nemakumi emakore, PU yakapedza kudzidza kubva kuPU foams (1960) kune yakaoma PU foam (polyisocyanurate foams-1967) seakawanda anofuridza maajenti, polyether polyols, uye polymeric isocyanate senge poly methylene diphenyl diisocyanate (PMDI) yakawanikwa.Aya maPMDI akavakirwa PU mafuro airatidza kunaka kwekupisa kwekupisa uye kunonoka kwemurazvo.
Muna 1969, tekinoroji yePU Reaction Injection Molding [PU RIM] yakaunzwa iyo yakaramba ichienderera mberi muReinforced Reaction Injection Molding [RRIM] ichigadzira yakakwira performance PU zvinhu izvo muna 1983 zvakaburitsa yekutanga purasitiki-muviri mota muUnited States.Mumakore ekuma1990, nekuda kwekuwedzera kwekuziva nezvenjodzi dzekushandisa chloro-alkanes seanofuridza (Montreal protocol, 1987), mamwe akawanda anofuridza akadururwa mumusika (semuenzaniso, carbon dioxide, pentane, 1,1,1,2- tetrafluoroethane, 1,1,1,3,3- pentafluoropropane).Panguva imwecheteyo, maviri-pack PU, PU-polyurea yekupfapfaidza coating tekinoroji yakauya mukutanga, iyo yakabereka zvakakosha zvekuve hunyoro kusanzwa nekukasira reactivity.Yakabva yatumbuka zano rekushandiswa kwemafuta emiriwo akavakirwa polyols mukuvandudza kwePU.Nhasi, nyika yePU yasvika kure kure kubva kuPU mahybrids, PU macomposites, asiri-isocyanate PU, ane mashandiro akasiyana mundima dzakasiyana siyana.Kufarira muPU kwakamuka nekuda kweiyo yakapusa synthesis uye application protocol, yakapusa (mashoma) ekutanga reactants uye yepamusoro zvimiro zvechigadzirwa chekupedzisira.Zvikamu zvirikuenderera zvinopa tsananguro pfupi yezvigadzirwa zvinodikanwa muPU synthesis pamwe nekemikari yakazara inobatanidzwa mukugadzirwa kwePU.
Declaration:Chinyorwa chakataurwa © 2012 Sharmin naZafar, ane rezinesi InTech.Chete chekukurukurirana uye kudzidza, usaite zvimwe zvekutengesa zvinangwa, hazvimiriri maonero nemafungiro ekambani, kana iwe uchida kudhindazve, ndapota taura nemunyori wepakutanga, kana paine kukanganisa, ndapota taura nesu nekukurumidza kuti tiite delete processing.