Dab tsi yog tsib feem ntau Isocyanates siv hauv Polyurethane Manufacturing?
Isocyanates yog ib qho ntawm cov khoom siv tseem ceeb tshaj plaws hauv kev tsim cov polyurethane. Lawv cuam tshuam nrog polyols los tsim polyurethane foams, elastomers, coatings, adhesives, sealants, thiab ntau lwm yam khoom lag luam. Xaiv qhov tsim nyog isocyanate muaj kev cuam tshuam ncaj qha rau kev coj tus cwj pwm, kev ua haujlwm ntawm lub tshuab, huab cua tsis kam, thiab cov khoom ua haujlwm ntev.
Ntawm ntau hom isocyanates muaj, tsib yog dav siv hauv polyurethane manufacturing: TDI, MDI, H12MDI, IPDI, thiab HDI. Txhua qhov muaj qhov tshwj xeeb zoo rau kev siv sib txawv.
Toluene Diisocyanate (TDI)
TDI yog ib qho ntawm feem ntau siv cov tshuaj tsw qab isocyanates hauv kev lag luam polyurethane. Cov qib lag luam feem ntau suav nrog cov khoom sib xyaw ntawm 2,4-TDI thiab 2,6-TDI isomers, nrog TDI-80 thiab TDI-100 yog cov khoom siv tshaj plaws.
Vim nws cov reactivity siab, TDI yog dav siv nyob rau hauv saj zawg zog polyurethane ua npuas ncauj, cam khwb cia polyurethane elastomers, adhesives, coatings, thiab sealants. Nws muab cov yam ntxwv ua tau zoo thiab tsim nyog rau ntau yam dav dav -lub hom phiaj polyurethane systems.
Txawm li cas los xij, cov khoom lag luam tsim nrog TDI feem ntau muaj qhov txwv tsis pub tiv thaiv ultraviolet lub teeb thiab tuaj yeem hloov xim tom qab lub sijhawm ntev - tawm sab nraum zoov. Rau cov ntawv thov uas xav tau ntev - lub sij hawm xim stability, aliphatic isocyanates feem ntau nyiam.
TDI yog cais raws li cov tshuaj lom neeg thiab yuav tsum tau khaws cia, thauj, thiab ua raws li cov cai tswj kev nyab xeeb. Kev tsim nyog qhov cua, cov cuab yeej tiv thaiv tus kheej, thiab kev tiv thaiv dej noo yog qhov tseem ceeb thaum ua haujlwm.
MDI (Methylene Diphenyl Diisocyanate)
MDI yog lwm qhov tseem ceeb ntawm isocyanate thiab tau dhau los ua ib qho ntawm cov khoom tseem ceeb tshaj plaws rau niaj hnub polyurethane ntau lawm.
Ntau cov ntaub ntawv lag luam muaj, suav nrog MDI ntshiab, polymeric MDI, thiab hloov ua kua MDI.
Ntshiab MDI feem ntau yog siv rau hauv thermoplastic polyurethane, cam khwb cia polyurethane elastomers, thiab tshwj xeeb polyurethane systems uas yuav tsum tau muaj kev ua haujlwm siab.
Polymeric MDI yog dav siv nyob rau hauv nruj polyurethane ua npuas ncauj, sandwich panels, rwb thaiv tsev ntaub ntawv, cov khoom siv tub yees, thiab kev tsim kho daim ntawv thov vim nws functionality ntau dua.
Hloov ua kua MDI txhim kho kev tuav cov yam ntxwv los ntawm kev txo cov crystallization thiab txhim kho kev ua haujlwm yooj yim.
Zoo li TDI, MDI-raws li cov khoom siv polyurethane feem ntau pom muaj qhov txwv UV tsis kam thiab tuaj yeem daj thaum lub sij hawm ntev sab nraum zoov tshwj tsis yog siv cov kev tiv thaiv ntxiv.
H12MDI (Hydrogenated MDI)
H12MDI yog alicyclic diisocyanate uas tsim los ntawm hydrogenating MDI. Tsis zoo li aromatic isocyanates, nws muaj kev tiv thaiv zoo rau ultraviolet lub teeb thiab huab cua.
Polyurethane systems raws li H12MDI tswj cov xim zoo heev txawm tias tom qab ntev - lub sij hawm raug sab nraum zoov. Qhov no ua rau H12MDI tshwj xeeb tshaj yog tsim rau cov txheej txheem hwm, pob tshab polyurethane cov khoom, cov dej hauv dej polyurethane dispersions, cov khoom siv kho qhov muag, thiab cov ntawv thov zoo nkauj.
Txawm hais tias H12MDI muab kev ua tau zoo heev, nws cov nqi tsim khoom yog siab dua li cov tshuaj tsw qab isocyanates, txwv nws siv rau siab - cov khoom muaj nqis.