Lignin muaj ntau pawg hydroxyl thiab yooj yim nkag tau raws li cov khoom lag luam ntawm cov ntaub so ntswg thiab cov ntawv lag luam, nws yog tus neeg sib tw zoo tshaj plaws raws li polyol precursor rau polyurethane. Lignin-raws li polyurethanes feem ntau yog tsim los ntawm reacting diisocyanate nrog hloov los yog tsis hloov lignin.
Txawm li cas los xij, lignin muaj qhov tsis zoo ib yam, tsis yog qhov tsawg tshaj plaws yog tias nws ua rau cov khoom tawg; Yog li ntawd, nws nquag ua ke nrog lwm cov polyols los txhim kho kev ua tau zoo. Txawm li cas los xij, tsuas yog kwv yees li 30% ntawm lignin yog qhov ua tau. Lwm qhov teeb meem yog lignin hydroxyl pab pawg tsis tshua muaj kev cuam tshuam nrog isocyanates, tshwj xeeb tshaj yog muaj ntxhiab isocyanates, vim muaj kev cuam tshuam tsis zoo. Txhawm rau daws qhov teeb meem no, cov kev hloov kho xws li hydroxypropylization feem ntau siv.
Qhov kawg-sealing isocyanate mus kom ze yog lwm txoj hauv kev rau kev tsim cov lignin-raws li polyurethanes uas tau siv dav hauv kev lag luam.nplaumtau tsim los ntawm pab pawg tshawb fawb ntawm ABC Federal University hauv Brazil.Qhov kev sib cuam tshuam thawj zaug nrog cov pab pawg polyol hydroxyl yog tiv thaiv los ntawm pawg isocyanate thawj cov tshuaj tiv thaiv nrog tus neeg sawv cev davhlau ya nyob twg, uas ua rau tsim cov pab pawg ua haujlwm uas muaj tshuaj lom neeg ruaj khov. Tsuas yog siab tshaj qhov kub ntawm qhov kev tiv thaiv pab pawg dissociates ua polyurethane bonds tsim.
Lignin los ntawm eucalyptus hardwood tau muab rho tawm thiab tom qab ntawd cuam tshuam nrog MDI siv cov roj castor ua tus thib ob polyol thiab diisopropylamine ua tus neeg sawv cev davhlau ya nyob twg. Lawv thov tias qhov tshwm sim ntawm polyurethane yog tsim nyog rau kev siv nyob rau hauv ib leeg-cov nplaum nplaum los yog txheej txheej uas ua kom siv cua sov. Ib leeg-lap shear tests ntawm steel substrates, tshwj xeeb tshaj yog, ua kom pom qhov ua tau zoo ntawm hydroxypropyl lignin-based polyurethanes.
Qhov zoo ntawm cov txheej txheem no suav nrog qis rhiab heev rau cov dej noo, qis toxicity thiab zoo cia ruaj khov vim qhov txo qis ntawm cyanate esters. Nws kuj tseem siv tau los tswj cov molar pawg thiab cov qauv molecular ntawm polyurethanes.