Izinto ezinobuningi bamaqembu e-hydroxyl zibizwa ngokuthi ama-spolyols.Angase futhi aqukathe i-ester, i-ether, i-amide, i-acrylic, insimbi, i-metalloid nokunye ukusebenza, kanye namaqembu e-hydroxyl.Ama-polyester polyols (PEP) aqukethe ama-ester nama-hydroxylic amaqembu kumgogodla owodwa.Ngokuvamile zilungiswa ukusabela kwe-condensation phakathi kwama-glycols, okungukuthi,
i-ethylene glycol, i-1,4-butane diol, i-1,6-hexane diol kanye ne-dicarboxylic acid/anhydride (aliphatic Polyurethane: Isingeniso 7 noma iphunga elimnandi).Izici ze-PU nazo zincike ezingeni lokuxhumanisa kanye nesisindo samangqamuzana se-PEP yokuqala.Nakuba i-PEP enamagatsha amaningi iphumela ku-PU eqinile enokushisa okuhle nokumelana namakhemikhali, i-PEP enegatsha elincane inikeza i-PU eguquguqukayo kahle (emazingeni okushisa aphansi) kanye nokumelana namakhemikhali aphansi.Ngokufanayo, ama-polyols anesisindo esiphansi samangqamuzana akhiqiza i-PU eqinile kuyilapho ama-polyols e-molecular high chain chain akhiqiza i-PU eguquguqukayo.Isibonelo esihle kakhulu se-PEP eyenzeka ngokwemvelo amafutha e-Castor.Amanye amafutha emifino (VO) ngokuguqulwa kwamakhemikhali nawo aphumela ku-PEP.I-PEP isengozini ye-hydrolysis ngenxa yokuba khona kwe
amaqembu e-ester, futhi lokhu kuholela ekuwohlokeni kwezakhiwo zabo zemishini.Le nkinga inganqotshwa ngokungezwa kwenani elincane lama-carbodiimide.Ama-polyether polyols(PETP) abiza kancane kune-PEP.Akhiqizwa ngokungezwa kokusabela kwe-ethylene noma i-propylene oxide ngotshwala noma iziqalisi ze-amine noma iziqalisi lapho kukhona i-asidi noma i-base catalyst.I-PU ethuthukiswe kusuka ku-PETP ibonisa ukufinyeleleka komswakama ophezulu kanye ne-Tg ephansi, ekhawulela ukusetshenziswa kwayo okubanzi kuma-coatings namapende.Esinye isibonelo sama-polyols yi-acrylated polyol (ACP) eyenziwe nge-polymerization yamahhala ye-radical ye-hydroxyl ethyl acrylate/methacrylate namanye ama-acrylic.I-ACP ikhiqiza i-PU enokuqina okushisayo okuthuthukisiwe futhi iphinde idlulisele izici ezijwayelekile zama-acrylics kumphumela we-PU.Lezi PU zithola izinhlelo zokusebenza njengezinto zokugqoka.Ama-Polyols abuye alungiswe ngosawoti wensimbi (isb., ama-acetate ensimbi, ama-carboxylates, ama-chloride) akha insimbi equkethe ama-polyols noma ama-polyols ayi-hybrid (MHP).I-PU etholwe ku-MHP ibonisa ukuzinza okuhle kokushisa, ukucwebezela nokuziphatha okulwa namagciwane.Imibhalo ibika izibonelo ezimbalwa ze-VO esekelwe ku-PEP, i-PETP, i-ACP, i-MHP esetshenziswa njengezisetshenziswa zokumboza ze-PU.Esinye isibonelo i-VO derived fatty amide diols and polyols (echazwe ngokuningiliziwe esahlukweni 20 Seed oil based polyurethanes: an insight), esebenze njengenhle kakhulu.
izinto zokuqala zokuthuthukiswa kwe-PU.Lezi PU zibonise ukuzinza okuhle kokushisa kanye nokumelana ne-hydrolytic ngenxa yokuba khona kweqembu le-amide kumgogodla we-diol noma we-polyol.

Isimemezelo:Isihloko sicashuniwe © 2012 Sharmin kanye no-Zafar, umnikazi welayisensi u-InTech.Ukuxhumana nokufunda kuphela, ungenzi ezinye izinjongo zezohwebo, akumele imibono nemibono yenkampani, uma udinga ukuphrinta kabusha, sicela uxhumane nomlobi wokuqala, uma kukhona ukwephulwa, sicela usithinte ngokushesha ukuze wenze ukucubungula ukususa.