Cov Khoom Ntawm Polyurethane Thiab Polyurethane Rubber
Taw qhia rau cov khoom ntawm polyurethane thiab polyurethane roj hmab polyurethane yog polymerized los ntawm polyester (los yog polyether) thiab diisocyanate tebchaw. Nws muaj qhov hnav tsis kam, ua raws li qhov zoo elasticity, siab hardness, roj kuj thiab hnyav kuj. Txawm hais tias polyurethane yuav tsum tau muab cais ua cov yas lossis roj hmab yog nyob ntawm qhov xwm txheej tiag tiag. Taiwan, Hong Kong thiab lwm cheeb tsam feem ntau hu ua plastics plastics, yog li nws tsis muaj nuj nqis kom nruj qhov sib txawv ntawm cov yas thiab roj hmab. Los ntawm qhov kev xav ntawm kev xav, qhov sib txawv ntawm cov yas thiab roj hmab feem ntau nyob ntawm seb lub iav hloov pauv kub (TG) ntawm cov khoom yog siab dua lossis qis dua chav tsev. Feem ntau, cov ntaub ntawv polymer nrog TG tsawg dua li qhov kub ib txwm hu ua plastics (xws li polyethylene nrog Tg ntawm - 78 degree), thaum cov ntaub ntawv polymer nrog TG siab dua li qhov kub ib txwm hu ua roj hmab. Polyurethane yog ib qho tshwj xeeb polymer, uas yog tsim los ntawm cov ntu tawv thiab ntu muag. Tg ntawm cov ntu nyuaj yog tsawg heev thiab muaj cov yam ntxwv ntawm cov yas. Tg ntawm cov ntu mos yog siab dua li chav tsev kub thiab muaj cov yam ntxwv ntawm cov roj hmab. Nyob rau hauv cov txheej txheem synthesis ntawm polyurethane, qhov kev faib ua feem ntawm cov ntu tawv thiab ntu mos ntawm polymer tuaj yeem hloov kho los ntawm kev tswj cov tshuaj tiv thaiv polymerization, kom polyurethane tuaj yeem coj tus cwj pwm zoo li yas lossis roj hmab. Polyurethane roj hmab (U) yog cov khoom ntawm cov tshuaj tiv thaiv ntawm oligomer Polyols (polyether glycol, polyester glycol los yog polyene glycol thiab polyether glycol uas muaj phosphorus, chlorine thiab fluorine), polyisocyanates thiab saw extenders nyob rau hauv lub xub ntiag ntawm catalysts. Polyurethane roj hmab tuaj yeem muab faib ua polyester polyurethane roj hmab (AU) thiab polyether polyurethane roj hmab (EU) raws li cov khoom siv raw siv sib txawv. Cov yam ntxwv ntawm polyurethane roj hmab molecules tsis tsuas yog txiav txim siab nws cov txiaj ntsig zoo ntawm lub cev thiab lub zog, tab sis kuj kho nws elasticity, txias tsis kam, modulus, hardness thiab mechanical zog los ntawm kev hloov cov muaj pes tsawg leeg, txheeb ze molecular hnyav thiab ester piv ntawm nws raw cov ntaub ntawv.
