Qhov sib txawv tseem ceeb ntawm isocyanate thiab diisocyanate yog isocyanate yog ib pab pawg ua haujlwm muaj nitrogen atom, carbon atom thiab oxygen atom sib koom ua ke ntawm ob daim ntawv cog lus thaum diisocyanate yog ib qho chaw muaj ob isocyanate anions lossis pawg ua haujlwm..
Isocyanate thiab diisocyanate zoo ib yam li ib leeg vim tias cov ntawv sib xyaw diisocyanate los ntawm kev sib xyaw ntawm ob pawg isocyanate. Qhov no yog li cas lub npe diisocyanate cov ntaub ntawv: "di-" prefix yog siv los qhia lub ntsiab lus "ob."
YIsocyanate yog dab tsi?
Isocyanate yog ib pawg ua haujlwm muaj cov tshuaj formula N=C=O. Yog li, peb tuaj yeem muab cov tshuaj formula ntawm ib qho isocyanate compound li R-N=C=O. Feem ntau, cov organic tebchaw uas muaj ib pawg isocyanate feem ntau hu ua isocyanate. Ib yam li ntawd, yog tias muaj ob pawg isocyanate hauv cov organic compound, peb tuaj yeem hu nws tias diisocyanate. Ntxiv mus, nws yog ib qho tseem ceeb kom paub qhov txawv ntawm cyanate esters thiab isocyanides vim tias lawv muaj qhov zoo sib xws. Ntawm no, pawg neeg ua haujlwm cyanate ester muaj kev sib txawv ntawm pawg isocyanate; pawg cyanate muaj O-C≡N qauv thaum isocyanate muaj O=C=N qauv.
Daim duab 01: Cov qauv ntawm Isocyanate-muaj Compound
Cov qauv ntawm isocyanate zoo ib yam li cov qauv ntawm carbon dioxide molecule. Qhov no yog vim hais tias ob qho tib si isocyanate thiab carbon dioxide muaj peb atoms nyob rau hauv ib tug linear geometry (carbon atom yog nruab nrab atom) thiab muaj ob daim ntawv cog lus ntawm peb atoms.
Peb tuaj yeem tsim cov tshuaj isocyanate siv amines ntawm phosgenation. Piv txwv li, peb tuaj yeem kho amines nrog phosgene kom tau isocyanate thiab hydrochloric acid ua cov khoom. Cov tshuaj tiv thaiv no, txawm li cas los xij, ua tiav los ntawm qhov nruab nrab (ib qho organic carbonyl chloride compound). Ntxiv mus, kev siv phosgene yog qhov txaus ntshai, yog li peb yuav tsum tau ceev faj thaum npaj isocyanate hauv txoj kev no.
Thaum xav txog qhov reactivity ntawm isocyanates, cov tebchaw no tuaj yeem ua raws li electrophiles. Yog li ntawd, lawv reactive rau ntau yam nucleophiles, nrog rau cawv, amines thiab dej. Piv txwv li, cov tshuaj tiv thaiv ntawm isocyanate thiab cawv ua rau muaj kev sib txuas ntawm urethane. Txawm li cas los xij, yog tias peb xav tau polyurethane, yuav tsum muaj ob pawg isocyanate ib molecule kom tau txais cov qauv polymerized; diisocyanate yog siv nyob rau hauv cov ntaub ntawv ntawd.
Disocyanate yog dab tsi?
Disocyanate yog ib lo lus siv los sau npe tshuaj lom neeg muaj ob pawg isocyanate ib molecule. Qhov no txhais tau tias cov tebchaw no muaj ob pawg N=C=O. Hauv cov tebchaw no, ob pawg isocyanate tuaj yeem tshwm sim ua anions lossis ua haujlwm ua haujlwm. Diisocyanates muaj txiaj ntsig zoo hauv kev tsim cov polyurethanes vim tias muaj ob pawg isocyanate uas tuaj yeem tsim ob lub urethane linkages ib molecule los tsim cov qauv polymerized.
Daim duab 02: Tsim cov Polyurethane siv Diol thiab Diisocyanate
Hauv cov txheej txheem polymerization ntawm kev tsim cov polyurethane, diisocyanate compound yuav tsum tau kho nrog cov organic compound uas muaj ob lossis ntau pawg hydroxyl. E.g. diols, polyols, thiab lwm yam. Qhov sib npaug dav rau polyurethane tsim yog raws li nram no:
Qhov txawv ntawm Isocyanate thiab Diisocyanate yog dab tsi?
Isocyanate thiab diisocyanate zoo ib yam li ib leeg vim tias cov ntaub ntawv diisocyanate los ntawm kev sib xyaw ntawm ob pawg isocyanate. Yog li ntawd, qhov sib txawv tseem ceeb ntawm isocyanate thiab diisocyanate yog tias isocyanate yog ib pab pawg ua haujlwm muaj nitrogen atom, carbon atom thiab oxygen atom sib koom ua ke ntawm ob daim ntawv cog lus thaum diisocyanate yog ib qho chaw muaj ob isocyanate anions lossis pawg ua haujlwm.
Hauv qab infographic tabulates qhov sib txawv ntawm isocyanate thiab diisocyanate.
Summary – Isocyanate vs Diisocyanate
Cov ntsiab lus isocyanate thiab diisocyante yog siv los tham txog kev npaj ntawm polyurethane. Qhov no yog vim hais tias diisocyante yog ib qho tseem ceeb raws li ib pab pawg neeg ua haujlwm uas yog siv hauv polyurethane ntau lawm. Qhov sib txawv tseem ceeb ntawm isocyanate thiab diisocyanate yog isocyanate yog ib pab pawg ua haujlwm muaj nitrogen atom, carbon atom thiab oxygen atom sib raug zoo rau ib leeg ntawm ob daim ntawv cog lus thaum diisocyanate yog ib qho chaw muaj ob isocyanate anions lossis pawg ua haujlwm.
