Los ntawm cov tshuaj pom kev sib pom, apolyol is tus cawv uas muaj ntau pawg hydroxyl. Ethanhan yog ib qho piv txwv ntawm dej cawv; Nws muaj ob tug carbons thiab ib pab pawg hydroxyl, thiab polyols muaj ntau pua pua lossis ntau txhiab tus carbons thiab ntau, ntau pawg hydroxyl. Muaj peb hom tseem ceeb: Polyether, Polyester thiab Polycarbonate.
Hauv kev tsim khoom, polycs muaj cov khoom tseem ceeb heev siv nyob rau ntau yam khoom siv txhua hnub, suav nrog cov khoom noj, cov khoom siv tsheb, cov khoom siv hauv tsev, pam pua chaw thiab lwm yam.
Nrog rau qhov no hauv siab, lub sij hawm polyol yuav muaj cov ntsiab lus sib txawv thiab ntau tshaj plaws txog ib qho piav qhia txog khoom noj thiab dej haus (piv txwv li cov ntaub ntawv txuj ci (piv txwv li, polymer chemistry).
Daim Ntawv Thov Polyols
Polyols tuaj yeem siv los ua polyurethane ua npuas thiab txheej, yog li lawv tuaj yeem siv ntau yam kev lag luam, xws li:
Rooj tog thiab txaj txaj
Xim av, txheej thiab cov nplaum
Kev Lag Luam Tsheb
Nkawm khau Thiab Khaub Ncaws
Rwb thaiv tsev thiab cov ntaub ntawv hauv tsev
Piv txwv li, Polyols tuaj yeem siv ua ke nrog ISOCYANATES los tsim cov polyurethane ua npuas dej rau ntawm daim txaj pw. Cov dummies zoo ib yam yog siv rau cov rooj zaum hauv tsheb kom ntseeg tau tias lawv muaj kev nyiam thiab tsheb sib tham kom tswj lub suab. Koj yuav tsis pom polyurethanes ntawm lub too ntawm koj nkawm khau, uas lawv muab cov hnoos qeev rau koj tus hneev taw.
Ntxiv rau lawv lub luag haujlwm hauv kev ua npuas dej, polyols tseem tuaj yeem ua raws li cov qab zib, thickeners thiab moururizers. Yog li ntawd, lawv kuj tseem siv tau dav hauv cov zaub mov thiab dej haus, cov chaw muag tshuaj thiab tshuaj pleev ib ce.
Hom Polyols
Polyether Polyols
Cov polymerization ntawm propylene oxide lossis ethylene oxide tsim polyether polyols. Cov qauv tseeb ntawm polyether tuaj yeem ua kom haum rau daim ntawv thov zaum kawg. Lawv tau ruaj khov rau dej, qaug zog acid thiab hauv paus. Lawv zoo li muaj lub cev hnyav dua.
Polyester Polyols
Reacting dicarboxylic acids (lossis lawv cov derivatives) nrog qee cov cawv ua rau polyester polyols. Kws tshaj lij Polyester Polyols, xws li Policaprolactone, yog tsim los ntawm lub nplhaib-qhib kev hloov pauv ntawm Cyclic esters. Cov polyols no muaj kev cuam tshuam ntau rau hydrolysis (rhuav tshem rau cov tshuaj tiv thaiv nrog dej) dua li polyether polyols. Lawv kuj nyiam kom muaj qis dua molecular hnyav dua polyether polyols.
Polycarbonate Polyols
Polycarbonate polyols yog qhov tseeb yog ib hom polyester polyol tab sis tus ester yog tus ester. Qhov sib txawv no txhais tau tias cov polyols yog ntau tiv taus hydrolysis ntau dua polyester polyols.