Izinto zokugquma i-polyurethane zivame ukutyheli ngokuhamba kwexesha ngenxa yokuvezwa ixesha elide kukukhanya kwe-ultraviolet okanye ubushushu, obuchaphazela inkangeleko yazo kunye nobomi benkonzo. Ngokuzisa i-UV-320 kunye ne-2-hydroxyethyl thiophosphate kwi-chain extension ye-polyurethane, i-polyurethane esekelwe emanzini e-nonionic enokumelana okugqwesileyo kwi-yellowing yalungiswa kwaye ifakwe kwi-leathing yesikhumba. Ngomahluko wombala, uzinzo, ukuskena i-electron microscope, i-X-ray spectrum kunye nezinye iimvavanyo, kwafunyaniswa ukuba umahluko opheleleyo wombala △E wesikhumba onyangwa ngamacandelo angama-50 e-polyurethane esekelwe emanzini e-nonionic ekwazi ukumelana nokutyheli yayiyi-2.9, ibakala lokutshintsha umbala laliyi-1, kwaye kwakukho utshintsho oluncinane kakhulu lombala. Idityaniswe nezalathisi ezisisiseko zokuqina kwesikhumba kunye nokunganyangeki kokunxiba, kubonisa ukuba i-polyurethane enganyangekiyo etyheli inokuphucula ukuxhathisa kwesikhumba ngelixa igcina iimpawu zayo zomatshini kunye nokumelana nokunxiba.

Njengoko imigangatho yokuphila yabantu iye yaphucuka, abantu baneemfuno eziphezulu zeekhushini zezitulo zesikhumba, ezingafuneki nje ukuba zingabi nabungozi kwimpilo yabantu, kodwa zifuna ukuba zithandeke ngobuhle. I-polyurethane esekelwe emanzini isetyenziswa ngokubanzi kwii-agent zesikhumba ngenxa yokhuseleko olugqwesileyo kunye nokusebenza okungenangcoliseko, i-gloss ephezulu, kunye nesakhiwo se-amino methylidynephosphonate esifana neso sikhumba. Nangona kunjalo, i-polyurethane yamanzi ixhomekeke kwi-yellowing phantsi kwefuthe lexesha elide lokukhanya kwe-ultraviolet okanye ukushisa, okuchaphazela ubomi benkonzo yezinto. Ngokomzekelo, izixhobo ezininzi ezimhlophe ze-polyurethane ezimhlophe zihlala zibonakala ziphuzi, okanye ukuya kwinqanaba elikhulu okanye elincinci, kuya kuba phuzi phantsi kokukhanya kwelanga. Ke ngoko, kunyanzelekile ukufunda ukumelana nokutyheli kwepolyurethane esekwe emanzini.

Okwangoku kukho iindlela ezintathu zokuphucula ukuchasana kwe-yellowing ye-polyurethane: ukulungelelanisa umlinganiselo wamacandelo anzima kunye athambileyo kunye nokutshintsha izinto eziluhlaza ukusuka kwingcambu yengcambu, ukongeza i-organic additives kunye ne-nanomaterials, kunye nokuguqulwa kwesakhiwo.

(a) Ukulungelelanisa umlinganiselo wamacandelo anzima kwaye athambileyo kunye nokutshintsha izinto eziluhlaza kunokusombulula kuphela ingxaki ye-polyurethane ngokwayo ethanda ukutyheli, kodwa ayikwazi ukusombulula impembelelo yendalo yangaphandle kwi-polyurethane kwaye ayikwazi ukuhlangabezana neemfuno zemarike Ngokusebenzisa i-TG, i-DSC, ukuxhathisa i-abrasion kunye novavanyo olunzima, kwafunyaniswa ukuba iipropati ezibonakalayo zemozulu elungiselelwe i-polyurethane ekwazi ukumelana ne-polyurethane kunye ne-polyurethane ecocekileyo kunye ne-polyurethane ecocekileyo yesikhumba. I-polyurethane ekwazi ukumelana nemozulu inokugcina iimpawu ezisisiseko zesikhumba ngelixa iphucula kakhulu ukuxhathisa kwayo kwimozulu.

(b) Ukongezwa kwezongezo ze-organic kunye ne-nanomaterials nazo zineengxaki ezifana nezixa eziphezulu zokongezwa kunye nokudibanisa okungahambi kakuhle komzimba kunye ne-polyurethane, okukhokelela ekunciphiseni kwiipropati ze-polyurethane mechanical.

(c) Iibhondi ze-Disulfide zinokuguqulwa okunamandla okuguquguqukayo, okwenza amandla abo okuvula aphantsi kakhulu, kwaye anokwaphulwa kwaye aphinde akhiwe amaxesha amaninzi. Ngenxa yokuguqulwa okuguquguqukayo kweebhondi ze-disulfide, ezi bhondi zihlala ziphulwa kwaye zakhiwe kwakhona phantsi kokukhanya kwe-ultraviolet irradiation, ukuguqula amandla okukhanya kwe-ultraviolet kukukhululwa kwamandla obushushu. I-yellowing ye-polyurethane ibangelwa ukukhanya kwe-ultraviolet irradiation, evuselela amabhondi ekhemikhali kwizinto ze-polyurethane kwaye ibangele ukuqhekeka kwebhondi kunye nokulungiswa ngokutsha, okukhokelela kutshintsho lwesakhiwo kunye nokutyheli kwe-polyurethane. Ngoko ke, ngokuzisa iibhondi ze-disulfide kumacandelo e-polyurethane chain chain, i-self-healing and yellowing resistance resistance ye-polyurethane yavavanywa. Ngokovavanyo lwe-GB/T 1766-2008, △E yayiyi-4.68, kwaye ibakala lokutshintsha kombala lalikwinqanaba lesi-2, kodwa ekubeni isebenzise i-tetraphenylene disulfide, enombala othile, ayifanelekanga kwi-polyurethane ekwazi ukumelana nokutyheli.

I-Ultraviolet light absorbers kunye ne-disulfides inokuguqula ukukhanya kwe-ultraviolet okufunxayo kukukhululwa kwamandla obushushu ukunciphisa impembelelo yokukhanya kwe-ultraviolet kwisakhiwo se-polyurethane. Ngokuzisa into eguqukayo eguquguqukayo i-2-hydroxyethyl disulfide kwinqanaba lokwandiswa kwe-polyurethane synthesis, ifakwe kwisakhiwo se-polyurethane, eyikhompawundi ye-disulfide equlethe amaqela e-hydroxyl ekulula ukusabela ngayo nge-isocyanate. Ukongeza, i-UV-320 i-ultraviolet absorber iqaliswa ukusebenzisana nokuphuculwa kokumelana ne-polyurethane etyheli. I-UV-320 equlethe amaqela e-hydroxyl, ngenxa yeempawu zayo zokusabela ngokulula kunye namaqela e-isocyanate, inokungeniswa kumacandelo ekhonkco le-polyurethane kwaye isetyenziswe kwidyasi ephakathi yesikhumba ukuphucula ukuxhathisa okutyheli kwe-polyurethane.

Ngovavanyo lomahluko wombala, kwafunyaniswa ukuba ukuxhathisa okutyheli kwe-polyureth etyheli yokumelana ne-TG, i-DSC, ukuxhathisa kwe-abrasion kunye novavanyo lokuqina, kwafunyaniswa ukuba iipropathi ezibonakalayo ze-polyurethane ekwazi ukumelana nemozulu kunye nesikhumba esiphathwe nge-polyurethane esulungekileyo yayihambelana, ebonisa ukuba i-polyurethane enganyangekiyo yemozulu inokugcina iimpawu ezisisiseko zesikhumba ngelixa iphucula kakhulu ukumelana nemozulu.