Qhov sib txawv tseem ceeb ntawm MDI thiab TDI yog tias MDI tshwm sim ua lub teeb daj crystalline khoom, whereas TDI tshwm sim raws li qhov tseeb, tsis muaj xim rau daj ntseg xim kua.
MDI thiab TDI yog ob hom sib txawv ntawm diisocyanates. Cov no muaj txiaj ntsig zoo hauv kev tsim cov polyurethane. Muaj ob hom loj ntawm diisocyanates li aromatic diisocyanates thiab aliphatic diisocyanates. MDI thiab TDI yog cov ntaub ntawv ntawm aromatic diisocyanates.
MDI yog dab tsi?
Lub sij hawm MDI sawv cev rau methylenediphenyl diisocyanate. Nws yog ib qho tseem ceeb rau kev tsim cov ntaub ntawv polyurethane rau ntau yam kev siv, xws li kev tsim cov polyurethane ua npuas ncauj uas muaj txiaj ntsig zoo rau kev rwb thaiv tsev hauv tsev thiab tub yees. Cov ntaub ntawv rwb thaiv tsev ua nrog MDI pab cov neeg siv khoom txuag hluav taws xob.
Ntawm qhov tod tes, muaj qee qhov kev siv MDI ntxiv, suav nrog kev tsim cov txheej txheem, cov nplaum nplaum, sealants, thiab elastomers. Peb tuaj yeem pom cov khoom xyaw no hauv cov khoom xws li cov xim pleev xim, cov nplaum, thiab cov ntaub ntawv tiv thaiv huab cua. Ntxiv mus, cov khoom siv no muaj txiaj ntsig zoo hauv kev ua ntau hom khau, cov khoom ua si thiab kev lom zem, thiab qee qhov tshwj xeeb ua npuas ncauj. Tsis tas li ntawd, peb tuaj yeem siv nws los ua cov ntawv khi rau ntoo thiab tsim cov pwm rau kev lag luam foundry.
Daim duab 01: Cov qauv ntawm Methyldiphenyl Diisocyanate
Thaum xav txog qhov muaj pes tsawg leeg ntawm MDI, chav tsev tshuaj lom neeg muaj nyob hauv cov khoom no yog 4, 4'-diphenylmethane diisocyanate. Feem ntau, nws yog lub teeb daj crystalline khoom uas tsis tshwm sim nyob rau hauv ib puag ncig. Yog li, yog tias cov tshuaj no tso rau hauv huab cua, dej thiab av, nws tuaj yeem ua rau muaj kev phom sij rau kev noj qab haus huv xws li ua pa.
TDI
Lub sij hawm TDI sawv cev rau toluene diisocyanate. Nws muaj txiaj ntsig zoo hauv kev tsim cov polyurethane. TDI feem ntau yog siv rau kev tsim cov khoom ua npuas ncauj, nrog rau cov ntaub pua plag thiab rooj tog zaum, cov ntaub pua plag hauv qab, ntim cov ntaub ntawv, thiab lwm yam. TDI cov khoom tseem ceeb hauv kev tsim cov coatings, sealants, adhesives, thiab elastomers. Ib yam li ntawd, cov khoom siv TDI muaj txiaj ntsig zoo hauv kev siv tsheb thauj mus los uas nws pab ua kom lub tsheb sib zog, ua rau kev txhim kho hauv kev siv roj tsheb thiab, yog li ntawd, kev txuag hluav taws xob.
Daim duab 02: Toluene Diisocyanate Structure
Thaum xav txog qhov muaj pes tsawg leeg ntawm TDI, chav tsev tshuaj lom neeg muaj nyob hauv cov khoom no yog 2, 4'-toluene diisocyanate. Feem ntau, nws yog ib qho ntshiab, tsis muaj xim rau daj ntseg xim kua uas tsis tshwm sim nyob rau hauv ib puag ncig. Yog li, yog tias cov tshuaj no tso rau hauv huab cua, dej thiab av, nws tuaj yeem ua rau muaj kev phom sij rau kev noj qab haus huv xws li ua pa.
Dab tsi yog qhov zoo sib xws ntawm MDI thiab TDI?
- MDI thiab TDI yog cov ntaub ntawv ntawm aromatic diisocyanates.
- Ob leeg yog cov tshuaj tsw qab.
Qhov txawv ntawm MDI thiab TDI yog dab tsi?
MDI thiab TDI yog ob hom diisocyanates uas tsis tshwm sim hauv ib puag ncig ib txwm muaj. MDI sawv cev rau methylenediphenyl diisocyanate, thaum TDI sawv cev rau toluene diisocyanate. Qhov sib txawv tseem ceeb ntawm MDI thiab TDI yog tias MDI yog lub teeb daj crystalline khoom, whereas TDI yog ib qho ntshiab, tsis muaj xim rau daj ntseg xim kua. Thaum xav txog cov tshuaj toxicity ntawm MDI thiab TDI, MDI muaj qhov tsis tshua muaj vapor siab dua li TDI, uas ua rau nws tsis muaj tshuaj lom. Yog li, qhov no yog lwm qhov sib txawv ntawm MDI thiab TDI. Tsis tas li ntawd, MDI feem ntau yog siv rau kev tsim cov polyurethane ua npuas ncauj, thaum TDI feem ntau yog siv rau kev tsim cov khoom siv tau yooj yim polyurethane foams.
Cov hauv qab no infographic qhia txog qhov sib txawv ntawm MDI thiab TDI hauv daim ntawv tabular.
Summary – MDI vs TDI
MDI thiab TDI yog ob hom diisocyanates uas tsis tshwm sim hauv ib puag ncig ib txwm muaj. Qhov sib txawv tseem ceeb ntawm MDI thiab TDI yog tias MDI tshwm sim raws li lub teeb daj crystalline khoom, whereas TDI tshwm sim raws li ib tug ntshiab, tsis muaj xim mus rau daj ntseg xim kua. Qhov tseem ceeb tshaj, MDI tsis muaj tshuaj lom ntau dua li TDI vim tias MDI muaj qhov sib piv qis vapor siab.
