Lub hauv paus ntsiab lus ntawm PU Solid Tyre Chemical Reaction
Peb lub log tsheb pu khoom siv bio-raws li kev tiv thaiv ib puag ncig polyether polyol thiab tag nrho cov txheej txheem dej foaming. Yog li ntawd, cov txheej txheem tsim khoom ntawm PU log yog ib puag ncig zoo.
1. Cov tshuaj tiv thaiv ntawm isocyanates nrog hydroxyl pawg
Isocyanate tuaj yeem hnov mob nrog cov nquag hydrogen ntawm hydroxyl uas muaj cov tshuaj xws li cawv, polyol, polyether thiab polyester los tsim carbamate.
2. Cov tshuaj tiv thaiv ntawm isocyanate nrog dej
Cov tshuaj tiv thaiv ntawm isocyanate nrog dej ua ntej tsim cov carbamate tsis ruaj khov, uas tom qab ntawd decomposed rau hauv carbon dioxide thiab amine.
R—NCO plus H2O → R—NHCOOH → R—NH2 plus CO2 R—NCO plus RNH2 → R—NHCONH—R
3. Cov tshuaj tiv thaiv isocyanates nrog cov amino pawg
Cov tshuaj tiv thaiv ntawm isocyanate nrog amine pawg tsim urea.
4. Cov tshuaj tiv thaiv ntawm isocyanate nrog urea
Cov tshuaj tiv thaiv ntawm isocyanate thiab hloov pauv urea ua rau biuret, uas tsim cov ceg ntoo lossis kev sib txuas.
5. Cov tshuaj tiv thaiv ntawm isocyanate nrog carbamate
Cov tshuaj tiv thaiv kev ua haujlwm ntawm isocyanate thiab carbamate qis dua li ntawm urea. Tsuas yog nyob rau hauv qhov kub thiab txias (120 ~ 1400C) los yog nyob rau hauv qhov kev txiav txim ntawm kev xaiv catalyst, isocyanate thiab carbamate tuaj yeem muaj cov tshuaj tiv thaiv txaus, thiab urea formate tuaj yeem tsim los ntawm polymerization.
6. Crosslinking cov tshuaj tiv thaiv ntawm isocyanate
Nyob rau hauv cov txheej txheem kev npaj polyurethane tiag tiag, txhawm rau txhim kho cov khoom siv kho tshuab ntawm cov khoom, qee qhov me me molecular cawv lossis amines uas muaj ntau tshaj 2 lub luag haujlwm yuav raug siv. Peb coj ternary cawv ua piv txwv los qhia txog kev sib cuam tshuam ntawm NCO, raws li hauv qab no:
