Ezinye izici ezibalulekile zokuwohloka kwe-polyester coating

Ukuwohloka kwe-polyester kuthinteka emisebeni yelanga, ingxube ye-photocatalytic, amanzi nomswakama, amakhemikhali, umoya-mpilo, i-ozone, izinga lokushisa, imihuzuko, ukucindezelwa kwangaphakathi nangaphandle, kanye nokufiphala kwe-pigment.Kukho konke lokhu, lezi zici ezilandelayo, zonke ezikhona esimweni sezulu sangaphandle, yilezi: Okubaluleke kakhulu ekunciphiseni isisindo:

umswakama, amazinga okushisa, i-oxidation, imisebe ye-UV.

umswakama

I-Hydrolysis yenzeka lapho ipulasitiki ivezwa emanzini noma kumswakama.Lokhu kusabela kwamakhemikhali kungase kube isici esikhulu ekucekeleni phansi kwama-polymers e-condensation njenge-polyester, lapho i-ester group i-hydrolyzed.

Temperature

Lapho i-polymer ingaphansi kwamandla okushisa amakhulu kunamandla ebhondi abambe ama-athomu ndawonye, ​​igoqeka kalula. Ngenxa yalokho, ama-macroradicals amabili, noma ama-molecule angenayo i-electron, akhiqizwa.
Amapulasitiki amaningi ayizakhi zofuzoralihlolwe ngaphansi kwezimo ezintathu zokuchayeka emazingeni okushisa aphakeme: izinga lokushisa eliphakeme phakathi nesikhathi eside, izinga lokushisa eliphakeme ngesikhathi esifushane, noma ukuchayeka ngemijikelezo emazingeni okushisa aphakeme noma aphansi, njengalokhu okungenzeka phakathi nokuchayeka emini nasebusuku. izinga lokushisa liyakhuphuka, imiphumela elimazayo ithuthukiswa ngokwengeziwe ukuchayeka kwe-UV okwengeziwe.

Ukuxhuma

Ngenxa yokuba khona komoya-mpilo emkhathini, uhlobo oluvame kakhulu lokuwohloka kwemisebe, i-photooxidation, lwenzeka kuwo wonke ama-polymers aphilayo. Futhi, inqubo izosheshiswa imisebe ye-UV kanye namazinga okushisa aphezulu. Ukusabela kwamakhemikhali kungachazwa ukuhlaselwa kwe-oksijeni kusibopho seketheni le-polymer, okungenzeka kube namaqembu e-carbonyl noma i-crosslink.Izinza ezihlukene zingasetshenziswa ukunciphisa ukuchithwa kwe-polymer: ama-antioxidants, ama-thermostabilizers, ama-photostabilizers, njll.

Imisebe ye-UV

Uma kuziwa ekusetshenzisweni kwangaphandle, okukhathaza kakhulu ekuhlolweni kwezinto ezibonakalayo ukucekelwa phansi kokukhanya kwelanga lapho amapulasitiki enzelwe ukusetshenziswa ngaphandle.Emisebeni ephelele efika emhlabeni, cishe u-5-6% wokukhanya usendaweni ye-UV. ye-spectrum futhi ngokuvamile izohluka ngezimo zezulu zemvelo zansuku zonke.
Umthelela we-photochemical wokukhanya kwelanga ezintweni zepulasitiki uncike ezicini zokumunca ngaphandle kanye namandla ebhondi yamakhemikhali wento. Amaza okukhanya anomthelela omkhulu kumapulasitiki asukela ku-290 kuye ku-400 nm. Ubude be-wavelength bemisebe ye-UV amandla ayo e-photon ahambisana namandla athile ebhondi ku-polymer chain angakwazi ukuphula izibopho zamakhemikhali (ngokusebenzisa i-chain scission), ukushintsha izakhiwo, ngakho-ke ukusebenza kwe-polymer.6 Ubude begagasi obulimaza kakhulu be-polyester kukholakala ukuthi 325 nm