Polyols

Lintho tse nang le bongata ba lihlopha tsa hydroxyl li bitsoa spolyols.E kanna ea ba le ester, ether, amide, acrylic, tšepe, metalloid le mesebetsi e meng, hammoho le lihlopha tsa hydroxyl.Polyester polyols (PEP) e na le lihlopha tsa ester le hydroxylic mokokotlong o le mong.Ka kakaretso li lokisoa ke karabelo ea condensation lipakeng tsa glycols, ke hore,
ethylene glycol, 1,4-butane diol, 1,6-hexane diol le dicarboxylic acid / anhydride (aliphatic Polyurethane: An Introduction 7 kapa monko o monate).Thepa ea PU e boetse e ipapisitse le boemo ba khokahano ea sefapano hammoho le boima ba limolek'hule tsa PEP e qalang.Le hoja PEP e nang le makala a mangata e fella ka PU e thata e nang le mocheso o motle le lik'hemik'hale tse hanyetsanang le lik'hemik'hale, PEP e fokolang ea branched e fana ka PU e nang le maemo a bonolo (ka mocheso o tlaase) le lik'hemik'hale tse tlaase tsa lik'hemik'hale.Ka mokhoa o ts'oanang, li-polyols tsa boima ba limolek'hule tse tlase li hlahisa PU e thata ha limolek'hule tse boima ba ketane e telele li fana ka PU e tenyetsehang.Mohlala o babatsehang oa PEP ea tlhaho ke Castor oil.Lioli tse ling tsa meroho (VO) ka liphetoho tsa lik'hemik'hale le tsona li baka PEP.PEP e ka hlaseloa habonolo ke hydrolysis ka lebaka la boteng ba
lihlopha tsa ester, 'me sena se boetse se lebisa ho senyeha ha thepa ea bona ea mechine.Bothata bona bo ka hlōloa ka ho eketsoa ha li-carbodiimide tse nyane.Polyether polyols(PETP) ha e theko e tlase ho feta PEP.Li hlahisoa ke karabelo ea tlatsetso ea ethylene kapa propylene oxide ka joala kapa li-amine tse qalang kapa li-initiators ka boteng ba acid kapa catalyst ea motheo.PU e hlahisitsoeng ho tsoa ho PETP e bonts'a ho kenella ha mongobo o phahameng le Tg e tlase, e fokotsang ts'ebeliso ea bona e pharaletseng ea litlolo le lipente.Mohlala o mong oa polyols ke acrylated polyol (ACP) e entsoeng ke free radical polymerization ea hydroxyl ethyl acrylate/methacrylate le li-acrylic tse ling.ACP e hlahisa PU e nang le botsitso bo ntlafalitsoeng ba mocheso hape e fana ka litšobotsi tse tloaelehileng tsa li-acrylics ho sephetho sa PU.Li-PU tsena li fumana lits'ebetso e le lisebelisoa tsa ho roala.Li-polyol li ntlafatsoa hape ka letsoai la tšepe (mohlala, li-acetate tsa tšepe, li-carboxylates, li-chloride) tse etsang tšepe e nang le polyols kapa hybrid polyols (MHP).PU e fumanoeng ho MHP e bonts'a botsitso bo botle ba mocheso, khanya le boitšoaro bo khahlanong le likokoana-hloko.Lingoliloeng li tlaleha mehlala e mengata ea VO e thehiloeng PEP, PETP, ACP, MHP e sebelisoang e le lisebelisoa tsa ho roala PU.Mohlala o mong ke VO derived fatty amide diols and polyols (e hlalositsoe ka botlalo khaolong ea 20 Oli ea peo e thehiloeng polyurethanes: temohisiso), e sebelitseng e le ntho e ntle haholo.
lisebelisoa tsa ho qala bakeng sa nts'etsopele ea PU.Li-PU tsena li bonts'itse botsitso bo botle ba mocheso le khanyetso ea hydrolytic ka lebaka la boteng ba sehlopha sa amide mokokotlong oa diol kapa polyol.

Phatlalatso:Sengoliloeng se qotsitsoe © 2012 Sharmin le Zafar, ba nang le lengolo la tumello InTech.Feela bakeng sa puisano le ho ithuta, u se ke ua etsa merero e meng ea khoebo, ha e emele maikutlo le maikutlo a k'hamphani, haeba u hloka ho hatisa hape, ka kopo ikopanye le mongoli oa pele, haeba ho na le tlōlo ea molao, ka kopo ikopanye le rona hang-hang ho etsa ts'ebetso ea ho hlakola.


Nako ea poso: Dec-20-2022