Txhawm rau daws qhov teeb meem ntawm cov txheej polyurethane ib txwm muaj feem yuav puas tsuaj thiab tsis muaj peev xwm kho tus kheej, cov kws tshawb fawb tau tsim cov txheej polyurethane kho tus kheej uas muaj 5 wt% thiab 10 wt% cov neeg sawv cev kho los ntawm Diels-Alder (DA) cycloaddition mechanism. Cov txiaj ntsig qhia tau hais tias kev siv cov neeg sawv cev kho mob ua rau lub txheej tawv dua los ntawm 3% -12% thiab ua tiav qhov kho tau zoo ntawm 85.6% -93.6% hauv 30 feeb ntawm 120 ° C, ua rau lub neej ua haujlwm ntev dua. Kev tshawb fawb no muab kev daws teeb meem tshiab rau kev tiv thaiv qhov chaw ntawm cov ntaub ntawv engineering.
Hauv kev lag luam ntawm cov ntaub ntawv engineering, kev kho cov khoom puas tsuaj hauv cov ntaub ntawv txheej tau ntev los ua qhov kev sib tw loj. Txawm hais tias cov txheej polyurethane ib txwm muaj kev tiv thaiv huab cua zoo heev thiab kev nplaum, lawv cov kev ua haujlwm tiv thaiv poob qis sai sai thaum khawb lossis tawg. Tau txais kev tshoov siab los ntawm cov txheej txheem kho tus kheej ntawm lub cev, cov kws tshawb fawb tau pib tshawb nrhiav cov ntaub ntawv kho tus kheej raws li cov dynamic covalent bonds, nrog rau Diels-Alder (DA) reaction tau txais kev saib xyuas tseem ceeb vim nws cov xwm txheej tsis tshua muaj zog thiab kev hloov pauv zoo. Txawm li cas los xij, kev tshawb fawb uas twb muaj lawm tau tsom mus rau cov kab ke polyurethane linear, tawm hauv qhov sib txawv hauv kev kawm txog cov khoom kho tus kheej hauv cov txheej txheem polyurethane hmoov txuas.
Txhawm rau kom hla dhau qhov kev cuam tshuam no, cov kws tshawb fawb hauv tebchaws tau tsim kho tshiab ob yam khoom siv kho DA—furan-maleic anhydride thiab furan-bismaleimide—rau hauv lub kaw lus polyester resin hydroxylated, tsim cov hmoov txheej polyurethane nrog cov khoom kho tus kheej zoo heev. Kev tshawb fawb siv ¹H NMR los lees paub cov qauv ntawm cov khoom siv kho, kev ntsuas calorimetry sib txawv (DSC) los txheeb xyuas qhov rov qab ntawm DA / retro-DA cov tshuaj tiv thaiv, thiab cov txheej txheem nanoindentation nrog rau cov qauv ntawm qhov chaw los ntsuas cov khoom siv kho tshuab thiab cov yam ntxwv ntawm qhov chaw ntawm cov txheej txheem.
Hais txog cov txheej txheem sim tseem ceeb, pab pawg tshawb fawb tau tsim cov tshuaj kho hydroxyl-muaj DA siv ob txoj kev. Tom qab ntawd, cov hmoov polyurethane uas muaj 5 wt% thiab 10 wt% cov tshuaj kho tau npaj los ntawm kev sib xyaw ua ke, thiab siv rau ntawm cov hlau siv cov tshuaj tsuag electrostatic. Los ntawm kev sib piv nrog cov pab pawg tswj tsis muaj cov tshuaj kho, qhov cuam tshuam ntawm kev sib xyaw ua ke ntawm cov tshuaj kho rau cov khoom siv tau raug tshawb xyuas tsis tu ncua.
1.Kev Tshuaj Xyuas NMR Pom Zoo Txog Cov Qauv Kho Mob
1 H NMR spectra qhia tau hais tias amine-inserted furan-maleic anhydride (HA-1) tau pom cov yam ntxwv ntawm DA ring peaks ntawm δ = 3.07 ppm thiab 5.78 ppm, thaum lub furan-bismaleimide adduct (HA-2) tau pom ib qho DA bond proton signal ntawm δ = 4.69 ppm, lees paub tias kev tsim cov tshuaj kho tau zoo.
2.DSC Qhia Txog Cov Yam Ntxwv Uas Hloov Tau Los Ntawm Qhov Kub
Cov kab DSC qhia tau hais tias cov qauv uas muaj cov tshuaj kho tau pom cov ncov endothermic rau DA cov tshuaj tiv thaiv ntawm 75 ° C thiab cov ncov yam ntxwv rau retro-DA tshuaj tiv thaiv hauv qhov ntau ntawm 110–160 ° C. Thaj chaw ncov nce nrog cov tshuaj kho ntau dua, qhia tau tias muaj kev hloov pauv thermal zoo heev.
3.Kev Ntsuas Nanoindentation Qhia Txog Kev Txhim Kho Hardness
Cov kev sim nanoindentation uas rhiab heev rau qhov tob qhia tau hais tias qhov ntxiv ntawm 5 wt% thiab 10 wt% cov neeg sawv cev kho tau ua rau lub txheej tawv dua los ntawm 3% thiab 12%, raws li. Tus nqi hardness ntawm 0.227 GPa tau khaws cia txawm tias nyob rau qhov tob ntawm 8500 nm, vim yog lub network sib txuas ua ke ntawm cov neeg sawv cev kho thiab polyurethane matrix.
4.Kev Tshawb Fawb Txog Qhov Nto
Kev ntsuam xyuas qhov roughness ntawm qhov chaw qhia tau hais tias cov txheej polyurethane ntshiab txo qhov Rz ntawm lub substrate los ntawm 86%, thaum cov txheej nrog cov tshuaj kho tau pom tias qhov roughness nce me ntsis vim muaj cov khoom loj dua. Cov duab FESEM pom tseeb qhia txog kev hloov pauv ntawm cov qauv ntawm qhov chaw uas tshwm sim los ntawm cov khoom kho.
5.Kev Tshawb Fawb Tshiab hauv Kev Kho Mob Scratch
Kev soj ntsuam ntawm lub tshuab tsom iav pom tau tias cov txheej txheej uas muaj 10 wt% tus neeg sawv cev kho, tom qab kho cua sov ntawm 120 ° C rau 30 feeb, tau pom tias qhov dav ntawm qhov khawb txo qis los ntawm 141 μm mus rau 9 μm, ua tiav qhov ua tau zoo ntawm 93.6%. Qhov kev ua tau zoo no zoo dua li qhov tau tshaj tawm hauv cov ntaub ntawv uas twb muaj lawm rau cov kab ke polyurethane linear.
Luam tawm hauv Cov Khoom Siv Tom Ntej, txoj kev tshawb fawb no muaj ntau yam kev tsim kho tshiab: Ua ntej, cov txheej txheem hmoov polyurethane DA-modified uas tau tsim ua ke cov khoom siv kho tshuab zoo nrog kev kho tus kheej, ua tiav kev txhim kho qhov nyuaj txog li 12%. Qhov thib ob, kev siv cov thev naus laus zis electrostatic spraying ua kom muaj kev sib kis ntawm cov neeg sawv cev kho mob hauv lub network sib txuas, kov yeej qhov tsis raug ntawm cov txheej txheem microcapsule ib txwm muaj. Qhov tseem ceeb tshaj plaws, cov txheej txheem no ua tiav kev kho mob zoo ntawm qhov kub qis dua (120 ° C), muab kev siv tau zoo dua piv rau qhov kub kho 145 ° C uas tau tshaj tawm hauv cov ntaub ntawv uas twb muaj lawm. Txoj kev tshawb fawb tsis yog tsuas yog muab txoj hauv kev tshiab los txuas lub neej kev pabcuam ntawm cov txheej txheem engineering xwb tab sis kuj tsim kom muaj lub moj khaum theoretical rau kev tsim cov txheej txheem ua haujlwm los ntawm nws qhov kev tshuaj xyuas ntau ntawm "kev sib raug zoo ntawm cov neeg sawv cev kho mob-kev ua tau zoo". Kev ua kom zoo dua yav tom ntej ntawm cov ntsiab lus hydroxyl hauv cov neeg sawv cev kho mob thiab qhov sib piv ntawm uretdione cross-linkers xav tias yuav thawb cov kev txwv kev ua haujlwm ntawm cov txheej txheem kho tus kheej.
Lub sijhawm tshaj tawm: Cuaj hlis-15-2025