Qhov kev sib tw ntawm PTMEG ntawm MTMEG ntawm MTMEG ntawm MTMEG ntxiv los ntawm qhov muaj txiaj ntsig ntawm txog 10- fold vs. qhov kev pheej hmoo ntawm PPG {}}} hom polyether polyols. Qhov no yog vim muaj kev hloov pauv ntau dua hydroxyl straw {}}} xaus hauv ptmeg vs. Ib qho preponderance ntawm ob lub ppg {{8} polyols. Hauv ppg polyols, ob qho tib si ob thiab thawj hydroxy saw {}}} xaus, hauv qhov sib piv ntawm 90:10. Siv DMC (ob chav hlau catalysts) catalevyeryn rau ppg- polyol ntau lawm nce cov ntsiab lus ntawm cov thawj hydroxy saw kawg {}} pawg. Hauv cov ntawv thov uas lub sijhawm ua kom ceev nrawm yog ntshaw lub sijhawm, PTMEG (thiab tseem ethylene oxide xaus-capped ppg polyols) yog nyiam. Qhov thib ob Hydroxyl Moieties ua nce hydrophobicity, yog li ntsuas hydrophobicity thiab reactivity tej zaum tseem ceeb.
PPG - polyols muaj nyob hauv cov tes hnyav ntau dua uas PTMEG thiab tuaj yeem ua haujlwm siab dua siv cov triol thiab tetraiol pib.
Lub ppg - polyols muaj ib qho tertiary hydrogen atom uas nyob ib sab lossis dej caw rau txhua chav. Cov no pab pawg atoms yog heev rau oxidative tsis muaj zog ntawm ppg {}}} Raws polyurethane elastomers. PTMEG polyol nraub qaum tsuas yog muaj qhov ruaj khov dua qub atomrary atoms, nrog qee qhov txuas ntxiv mus rau ether lossis hydoxyl sib txuas.
Lub PTMEG polyol qib slate muaj cov diol nrog cov phaus molecular zoo li ntawm 210, 1800, 2000 thiab 350 yog kua ntawm chav tsev. Yog tias crosslinking yog qhov xav tau, Triols zoo li TMP lossis tsawg molecular hnyav ppg- Triols raug pom zoo.
Lub ppg -} Raws polyols muaj ntau haiv neeg nplua nuj ntawm cov khoom lag luam. Molecular hnyav li cas los ntawm, 400 lossis qis dua mus rau saum 5000. Kev ua haujlwm ntau yam los ntawm Diol, Triols thiab TetRauols mus rau saum toj xya. Sucrose pib polyols tuaj yeem muaj kev ua haujlwm ntawm ntau dua xya. Qhov nce ntxiv ntawm cov haujlwm siab dua polyols muab rau kev ua kom muaj zog ua kom nruj thiab hardness, thiab txhim kho cov tshuaj lom neeg tsis kam thiab thermalistance. Thaum lub ppg raws polyols yog xaus - capped nrog ethylene oxide, lub txiaj ntsig} kev ntsuas yog qhov ua tau zoo dua hydroxyls.