Ukuze kuxazululwe inkinga yokuthi izembozo ze-polyurethane ezivamile zisengozini yokulimala futhi azinawo amakhono okuziphilisa, abacwaningi bathuthukise izembozo ze-polyurethane eziziphilisayo eziqukethe ama-5 wt% kanye nama-10 wt% ezokwelapha ngokusebenzisa indlela ye-Diels-Alder (DA) cycloaddition. Imiphumela ikhombisa ukuthi ukufakwa kwama-ejenti okuphulukisa kwandisa ubulukhuni bezembozo ngo-3%–12% futhi kufeza ukusebenza kahle kokuphulukisa okungu-85.6%–93.6% zingakapheli imizuzu engama-30 ku-120 °C, okwandisa kakhulu impilo yezembozo. Lolu cwaningo luhlinzeka ngesisombululo esisha sokuvikela ubuso bezinto zobunjiniyela.
Emkhakheni wezinto zobunjiniyela, ukulungiswa komonakalo wemishini ezintweni zokumboza sekuyisikhathi eside kuyinselele enkulu. Nakuba izembozo ze-polyurethane zendabuko zibonisa ukumelana nesimo sezulu okuhle kakhulu kanye nokunamathela, ukusebenza kwazo kokuvikela kuyawohloka ngokushesha uma kuvela imihuzuko noma imifantu. Bephefumulelwe izindlela zokuziphilisa zebhayoloji, ososayensi sebeqalile ukuhlola izinto zokuziphilisa ezisekelwe ezibophweni ze-covalent ezinamandla, kanye nokusabela kwe-Diels-Alder (DA) okuthola ukunakwa okukhulu ngenxa yezimo zayo zokusabela okuncane kanye nokuguqulwa okuhle. Kodwa-ke, ucwaningo olukhona lugxile kakhulu ezinhlelweni ze-polyurethane eziqondile, okushiya igebe esifundweni sezakhiwo zokuziphilisa ezimbozweni ze-polyurethane powder ezixhumene ne-cross-linked.
Ukuze badlule kulesi sithiyo sobuchwepheshe, abacwaningi basekhaya bafaka izinto ezimbili zokwelapha ze-DA—i-furan-maleic anhydride kanye ne-furan-bismaleimide—esimisweni se-resin ye-polyester ene-hydroxylated, bakha i-polyurethane powder coating enezakhiwo ezinhle kakhulu zokuziphilisa. Ucwaningo lusebenzise i-¹H NMR ukuqinisekisa isakhiwo sezinto zokwelapha, i-differential scanning calorimetry (DSC) ukuqinisekisa ukuguquguquka kokusabela kwe-DA/retro-DA, kanye namasu e-nanoindentation kanye ne-surface profilometry ukuhlola ngokuhlelekile izakhiwo zemishini kanye nezici zobuso bezinto ezimbozwayo.
Ngokuphathelene namasu okuhlola abalulekile, ithimba locwaningo laqala ngokwakha izinto zokwelapha ze-DA eziqukethe i-hydroxyl kusetshenziswa indlela yezinyathelo ezimbili. Ngemva kwalokho, izimpushana ze-polyurethane eziqukethe izinto zokwelapha ezingu-5 wt% kanye no-10 wt% zalungiswa ngokuxuba okuncibilikisiwe, futhi zafakwa ezisekelweni zensimbi kusetshenziswa ukufutha nge-electrostatic. Ngokuqhathanisa namaqembu okulawula angenazo izinto zokwelapha, ithonya lokuhlushwa kwezinto zokwelapha ezimpahleni zezinto lahlolwa ngokuhlelekile.
1.Ukuhlaziywa kwe-NMR Kuqinisekisa Ukwakheka Kwe-Agent Yokwelapha
1 I-H NMR spectra ikhombisile ukuthi i-amine-inserted furan-maleic anhydride (HA-1) ibonise iziqongo zendandatho ye-DA eziphawulekayo ku-δ = 3.07 ppm kanye no-5.78 ppm, kuyilapho i-furan-bismaleimide adduct (HA-2) ibonise isignali ejwayelekile ye-DA bond proton ku-δ = 4.69 ppm, okuqinisekisa ukwenziwa okuphumelelayo kwama-ejenti okuphulukisa.
2.I-DSC Yembula Izici Eziguquka Ngokushisa
Ama-curve e-DSC abonise ukuthi amasampula aqukethe izinto zokwelapha abonise iziqongo ze-endothermic zokusabela kwe-DA ku-75 °C kanye neziqongo eziphawulekayo zokusabela kwe-retro-DA ebangeni eliphakathi kuka-110–160 °C. Indawo ephezulu yanda ngokuqukethwe okuphezulu kwezinto zokwelapha, okubonisa ukuguquguquka okuhle kokushisa.
3.Ukuhlolwa kwe-Nanoindentation Kubonisa Ukuthuthukiswa Kokuqina
Ukuhlolwa kwe-nanoindentation okuzwela ukujula kwembule ukuthi ukwengezwa kwezinto zokwelapha ezingu-5 wt% kanye no-10 wt% kwandisa ubulukhuni bokumboza ngo-3% kanye no-12%, ngokulandelana. Inani lobulukhuni elingu-0.227 GPa lagcinwa ngisho nasekujuleni okungu-8500 nm, okubangelwa inethiwekhi exhunywe phakathi kwezinto zokwelapha kanye ne-polyurethane matrix.
4.Ukuhlaziywa Kwesimo Sendawo
Ukuhlolwa kobulukhuni bomphezulu kubonise ukuthi ukugqoka okumsulwa kwe-polyurethane kunciphisa inani le-substrate Rz ngo-86%, kuyilapho ukugqoka okune-ejenti yokuphulukisa kubonise ukwanda okuncane kobulukhuni ngenxa yokuba khona kwezinhlayiya ezinkulu. Izithombe ze-FESEM zibonisa izinguquko ezibonakalayo ekubunjweni komphezulu okuvela ezinhlayiyeni ze-ejenti yokuphulukisa.
5.Ukuphumelela Ekusebenzeni Kahle Kokwelapha Ukuklwebheka
Ukubonwa kwe-optical microscopy kubonise ukuthi izembozo eziqukethe i-10 wt% yokuphulukisa, ngemva kokwelashwa ngokushisa ku-120 °C imizuzu engama-30, zibonise ukwehla kobubanzi bokuklwebheka kusuka ku-141 μm kuya ku-9 μm, okufeza ukusebenza kahle kokuphulukisa okungu-93.6%. Lokhu kusebenza kuphakeme kakhulu kunalokho okubikwe ezincwadini ezikhona zezinhlelo ze-polyurethane eziqondile.
Kushicilelwe ku-Next Materials, lolu cwaningo lunikeza izinto ezintsha eziningi: Okokuqala, izembozo zempuphu ze-polyurethane eziguqulwe yi-DA ezithuthukisiwe zihlanganisa izakhiwo ezinhle zemishini nekhono lokuziphilisa, zifinyelele ekuthuthukisweni kobulukhuni obufika ku-12%. Okwesibili, ukusetshenziswa kobuchwepheshe bokufafaza nge-electrostatic kuqinisekisa ukusabalala okufanayo kwezakhi zokwelapha ngaphakathi kwenethiwekhi exhunywe nge-cross-linked, kunqobe ukungalungi kokubeka okuvamile kwamasu endabuko e-microcapsule. Okubaluleke kakhulu, lezi zembozo zithola ukusebenza kahle kokuphulukisa okuphezulu ekushiseni okuphansi (120 °C), okunikeza ukusebenza okukhulu kwezimboni uma kuqhathaniswa nokushisa kokuphulukisa okungu-145 °C okubikwe ezincwadini ezikhona. Lolu cwaningo alugcini nje ngokunikeza indlela entsha yokwandisa impilo yenkonzo yezembozo zobunjiniyela kodwa futhi lusungula uhlaka lwethiyori lokuklama kwama-molecule ezembozo ezisebenzayo ngokuhlaziya kwalo okulinganiselwe kobudlelwano "bokuhlushwa kokusebenza kwe-ejenti yokuphulukisa". Ukuthuthukiswa kwesikhathi esizayo kokuqukethwe kwe-hydroxyl kuma-ejenti okuphulukisa kanye nesilinganiso se-uretdione cross-linkers kulindeleke ukuthi kuqhubeke nokucindezela imikhawulo yokusebenza yezembozo zokuziphilisa.
Isikhathi sokuthunyelwe: Septhemba 15-2025