Pofuna kuthana ndi vuto la zophimba za polyurethane zomwe zimagwiritsidwa ntchito nthawi zambiri zimawonongeka komanso sizimatha kudzichiritsa zokha, ofufuza adapanga zophimba za polyurethane zomwe zimadzichiritsa zokha zomwe zili ndi 5 wt% ndi 10 wt% zochiritsa kudzera mu njira ya Diels-Alder (DA) cycloaddition. Zotsatira zake zikusonyeza kuti kuphatikiza zinthu zochiritsa kumawonjezera kuuma kwa zophimba ndi 3%–12% ndipo kumakwaniritsa mphamvu zochiritsa za 85.6%–93.6% mkati mwa mphindi 30 pa 120 °C, zomwe zimakulitsa kwambiri moyo wa zophimbazo. Kafukufukuyu akupereka njira yatsopano yotetezera pamwamba pa zipangizo zaukadaulo.
Mu gawo la zipangizo zauinjiniya, kukonza kuwonongeka kwa makina mu zipangizo zophikira kwakhala vuto lalikulu kwa nthawi yayitali. Ngakhale kuti zophikira za polyurethane zachikhalidwe zimawonetsa kukana bwino nyengo komanso kumamatira, magwiridwe antchito awo oteteza amachepa mwachangu akangogwa kapena ming'alu. Motsogozedwa ndi njira zamoyo zodzichiritsira, asayansi ayamba kufufuza zinthu zodzichiritsira kutengera ma dynamic covalent bonds, ndipo Diels-Alder (DA) reaction ikupeza chidwi chachikulu chifukwa cha momwe imachitira pang'ono komanso kuthekera kosinthika bwino. Komabe, kafukufuku yemwe alipo wayang'ana kwambiri machitidwe a polyurethane olunjika, kusiya mpata mu kafukufuku wa makhalidwe odzichiritsira okha mu zophikira za polyurethane powder zolumikizidwa.
Pofuna kuthana ndi chopinga ichi chaukadaulo, ofufuza am'deralo adayambitsa mwaluso mankhwala awiri ochiritsa a DA—furan-maleic anhydride ndi furan-bismaleimide—mu dongosolo la hydroxylated polyester resin, ndikupanga utoto wa polyurethane powder wokhala ndi mphamvu zabwino zodzichiritsa. Kafukufukuyu adagwiritsa ntchito ¹H NMR kutsimikizira kapangidwe ka mankhwala ochiritsa, differential scanning calorimetry (DSC) kuti atsimikizire kusinthika kwa machitidwe a DA/retro-DA, ndi njira za nanoindentation pamodzi ndi surface profilometry kuti ayese mwadongosolo makhalidwe a makina ndi mawonekedwe a pamwamba pa utoto.
Ponena za njira zazikulu zoyesera, gulu lofufuza linayamba kupanga mankhwala ochiritsa a DA okhala ndi hydroxyl pogwiritsa ntchito njira ya magawo awiri. Pambuyo pake, ufa wa polyurethane wokhala ndi mankhwala ochiritsa a 5 wt% ndi 10 wt% unakonzedwa kudzera mu kusakaniza kosungunuka, ndipo unagwiritsidwa ntchito pazitsulo pogwiritsa ntchito kupopera kwa electrostatic. Poyerekeza ndi magulu olamulira opanda mankhwala ochiritsa, mphamvu ya kuchuluka kwa mankhwala ochiritsa pa zinthu zina inafufuzidwa mwadongosolo.
1.Kusanthula kwa NMR Kutsimikizira Kapangidwe ka Wothandizira Kuchiritsa
1 H NMR spectra inasonyeza kuti amine-inserted furan-maleic anhydride (HA-1) inasonyeza DA ring peaks pa δ = 3.07 ppm ndi 5.78 ppm, pomwe furan-bismaleimide adduct (HA-2) inasonyeza chizindikiro cha DA bond proton pa δ = 4.69 ppm, kutsimikizira kupanga bwino kwa mankhwala ochiritsa.
2.DSC Ikuwulula Makhalidwe Osinthika ndi Kutentha
Ma curve a DSC adawonetsa kuti zitsanzo zomwe zili ndi mankhwala ochiritsa zidawonetsa ma endothermic peaks a DA reaction pa 75 °C ndi ma peaks apadera a retro-DA reaction pa 110–160 °C. Malo okwera adawonjezeka ndi kuchuluka kwa mankhwala ochiritsa, zomwe zikuwonetsa kusinthika kwabwino kwa kutentha.
3.Mayeso a Nanoindentation Amasonyeza Kukonza Kulimba
Mayeso a nanoindentation ozama kwambiri adawonetsa kuti kuwonjezera kwa mankhwala ochiritsa a 5 wt% ndi 10 wt% kunawonjezera kuuma kwa utoto ndi 3% ndi 12%, motsatana. Kuuma kwa 0.227 GPa kunasungidwa ngakhale pa kuya kwa 8500 nm, chifukwa cha netiweki yolumikizidwa yopangidwa pakati pa mankhwala ochiritsa ndi polyurethane matrix.
4.Kusanthula kwa Maonekedwe a Pansi
Mayeso okhudza kuuma kwa pamwamba adawonetsa kuti zokutira za polyurethane zoyera zidachepetsa mtengo wa Rz wa substrate ndi 86%, pomwe zokutira zokhala ndi zinthu zochiritsa zidawonetsa kuwonjezeka pang'ono kwa kuuma chifukwa cha kupezeka kwa tinthu tating'onoting'ono tating'onoting'ono. Zithunzi za FESEM zidawonetsa kusintha kwa kapangidwe ka pamwamba komwe kumachitika chifukwa cha tinthu tating'onoting'ono ta zinthu zochiritsa.
5.Kupambana kwa Kuchiza Koyamba
Kuwona kwa ma microscopy a kuwala kunawonetsa kuti zokutira zokhala ndi 10 wt% yochiritsa, pambuyo pa kutentha pa 120 °C kwa mphindi 30, zinawonetsa kuchepa kwa kukula kwa kukanda kuchokera pa 141 μm kufika pa 9 μm, zomwe zinapangitsa kuti kuchiritsa kukhale kothandiza ndi 93.6%. Kugwira ntchito kumeneku ndi kwabwino kwambiri kuposa komwe kunanenedwa m'mabuku omwe alipo a linear polyurethane systems.
Pofalitsidwa mu Next Materials, kafukufukuyu akupereka zinthu zambiri zatsopano: Choyamba, zokutira za ufa wa polyurethane zopangidwa ndi DA zomwe zapangidwa zimaphatikiza makhalidwe abwino amakina ndi mphamvu yodzichiritsa yokha, zomwe zimapangitsa kuti kuuma kukhale bwino mpaka 12%. Chachiwiri, kugwiritsa ntchito ukadaulo wopopera wamagetsi kumatsimikizira kufalikira kofanana kwa zinthu zochiritsa mkati mwa netiweki yolumikizidwa, kuthana ndi kusalondola kwa malo komwe kumachitika panjira zachikhalidwe za microcapsule. Chofunika kwambiri, zokutira izi zimapangitsa kuti zichiritse bwino kwambiri pa kutentha kochepa (120 °C), zomwe zimapangitsa kuti zikhale zogwiritsidwa ntchito kwambiri m'mafakitale poyerekeza ndi kutentha kwa 145 °C komwe kwanenedwa m'mabuku omwe alipo. Kafukufukuyu samangopereka njira yatsopano yowonjezerera moyo wa ntchito ya zokutira zaukadaulo komanso amakhazikitsa njira yophunzitsira kapangidwe ka mamolekyulu a zokutira zogwira ntchito kudzera mu kusanthula kwake kuchuluka kwa ubale wa "kuchuluka kwa zinthu zochiritsa-kugwira ntchito". Kukonzanso mtsogolo kwa kuchuluka kwa hydroxyl m'zinthu zochiritsa ndi chiŵerengero cha uretdione cross-linkers kukuyembekezeka kupititsa patsogolo malire a magwiridwe antchito a zokutira zodzichiritsa zokha.
Nthawi yotumizira: Sep-15-2025