Cov khoom uas muaj ntau yam ntawm pawg hydroxyl yog hu ua spolyols.Lawv kuj tseem muaj ester, ether, amide, acrylic, hlau, metalloid thiab lwm yam haujlwm, nrog rau cov pab pawg hydroxyl.Polyester polyols (PEP) muaj ester thiab hydroxylic pawg nyob rau hauv ib tug qaum.Lawv feem ntau yog npaj los ntawm cov tshuaj tiv thaiv condensation ntawm glycols, piv txwv li,
ethylene glycol, 1,4-butane diol, 1,6-hexane diol thiab dicarboxylic acid / anhydride (aliphatic Polyurethane: Kev Taw Qhia 7 lossis aromatic).Cov khoom ntawm PU kuj nyob ntawm seb qhov kev sib txuas ntawm kev sib txuas nrog rau qhov hnyav molecular ntawm PEP pib.Thaum PEP cov ceg tawv heev ua rau PU tawv nrog cov cua sov zoo thiab cov tshuaj tiv thaiv, tsis tshua muaj ceg PEP muab PU nrog kev yooj yim (ntawm qhov kub thiab txias) thiab tsis muaj tshuaj lom neeg.Ib yam li ntawd, tsis tshua muaj molecular hnyav polyols tsim nruj PU thaum siab molecular hnyav ntev saw polyols yield hloov tau PU.Ib qho piv txwv zoo ntawm qhov tshwm sim PEP yog Castor roj.Lwm cov roj zaub (VO) los ntawm kev hloov tshuaj lom neeg kuj ua rau PEP.PEP yog raug rau hydrolysis vim muaj cov
ester pawg, thiab qhov no kuj ua rau qhov tsis zoo ntawm lawv cov khoom siv tshuab.Qhov teeb meem no tuaj yeem kov yeej los ntawm kev ntxiv me ntsis ntawm carbodiimides.Polyether polyols (PETP) tsis tshua kim dua PEP.Lawv yog tsim los ntawm cov tshuaj tiv thaiv ntxiv ntawm ethylene los yog propylene oxide nrog cawv los yog amine starters los yog pib nyob rau hauv muaj cov kua qaub los yog lub hauv paus catalyst.PU tsim los ntawm PETP qhia cov dej noo permeability thiab qis Tg, uas txwv tsis pub lawv siv dav hauv cov txheej thiab xim.Lwm qhov piv txwv ntawm polyols yog acrylated polyol (ACP) ua los ntawm cov dawb radical polymerization ntawm hydroxyl ethyl acrylate / methacrylate nrog rau lwm cov acrylics.ACP tsim PU nrog kev txhim kho thermal stability thiab tseem muab cov yam ntxwv ntawm acrylics rau PU.Cov PU no pom cov ntawv thov ua cov ntaub ntawv txheej.Polyols raug hloov kho ntxiv nrog cov ntsev hlau (xws li hlau acetates, carboxylates, chlorides) ua cov hlau uas muaj polyols lossis hybrid polyols (MHP).PU tau los ntawm MHP qhia tau zoo thermal stability, gloss thiab anti-microbial cwj pwm.Cov ntaub ntawv qhia ntau yam piv txwv ntawm VO raws li PEP, PETP, ACP, MHP siv los ua PU txheej txheej.Lwm qhov piv txwv yog VO muab tau los ntawm fatty amide diols thiab polyols (piv txwv li hauv tshooj 20 Cov noob roj raws li polyurethanes: kev pom), uas tau ua haujlwm zoo heev.
pib cov ntaub ntawv rau kev loj hlob ntawm PU.Cov PU no tau pom zoo thermal stability thiab hydrolytic tsis kam vim muaj cov pab pawg amide hauv diol lossis polyol qaum.

Tshaj Tawm: Cov kab lus no tau hais los ntawm © 2012 Sharmin thiab Zafar, tus neeg tso cai InTech .Tsuas yog rau kev sib txuas lus thiab kev kawm, tsis txhob ua lwm yam kev lag luam lub hom phiaj, tsis sawv cev rau lub tuam txhab kev pom thiab kev xav, yog tias koj xav tau rov luam dua, thov hu rau tus thawj sau, yog tias muaj kev ua txhaum cai, thov hu rau peb tam sim ntawd kom tshem tawm cov txheej txheem.