Hauv kev lag luam, kev tsim cov loj polyesols yog cov txheej txheem batch.
Hauv thawj theem, cov polyols (ethylene glycol, triethylene glycol, pusylene glycol, thiab lwm yam) etcour acid, thiab lwm yam) lossis wb (phthalic anhydride, thiab lwm yam) ntawm 140 - 200℃rau Esterification thiab Polycondensation cov kev coj ua. Qhov ntsuas kub nyob rau sab saum toj ntawm fractionation ntauwd yog tswj hwm ntawm 100 - 102 degree. Tom qab stripping deb feem ntau ntawm cov khoom siv los ntawm cov khoom siv sib txawv, cov tshuaj tiv thaiv tau tswj hwm ntawm {101 - 2 teev. Txij ntawm no, cov acid acid tau feem ntau tsis kam txais rau20 - 30 mg koh / g.
Hauv theem ob, lub tshuab nqus tsev yog thov, thiab lub tshuab nqus tsev yog maj mam nce. Cov kab dej thiab ntau dhau polyols raug muab tshem tawm nyob rau hauv cov kev coj ua ntawm cov khoom muaj txiaj ntsig polyols, uas tuaj yeem hu tau tias yog "lub tshuab nqus melting". Hloov pauv, inert gases xws li nitrogen tuaj yeem qhia txuas ntxiv kom tshem dej, hu ua "cov cab kuj muaj suab". Nyob rau hauv cov tshuaj tiv thaiv system, ib co - boiling solvent xws li cov dej tsim tau ntxiv, thiab maj mam tshem tawm siv cov dej sepuard thaum lub toluene. Cov qauv no hu ua "co - boiling distillation txoj kev".
Ntau hom sib txawv ntawm polyester polyols muaj cov khoom sib txawv vim lawv cov txheej txheem sib txawv lossis kev npaj. Qhov ntsuas ntau rau Polyester Polyols yog tus nqi hydroxyl, acidenture cov ntsiab lus, hnyav cov ntsiab lus, hnyav molecosity, thiab xim.
Nyem qhov no mus nrhiav rau cov khoom lag luam xws liraws li polyester polyols
https://www.koyonchem.com/polyols/polyesterontesterontesterontesolyol/
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