Poly(ethylene terephthalate) (PET)yimathiriyeli yokupakisha edla ngokusetyenziswa kushishino lokutya nesiselo; ngoko ke, ukuzinza kwayo kwe-thermal kuye kwafundwa ngabaphandi abaninzi. Ezinye zezi zifundo ziye zabeka ugxininiso kwisizukulwana se-acetaldehyde (AA). Ubukho be-AA ngaphakathi kwamanqaku e-PET bunenkxalabo kuba inendawo yokubilisa kwindawo okanye ngaphantsi kweqondo lokushisa (21_C). Oku kuguquguquka kobushushu obuphantsi kuya kuyivumela ukuba isasazeke ukusuka kwi-PET ukuya emoyeni okanye nayiphi na imveliso ngaphakathi kwesikhongozeli. Ukusasazwa kwe-AA kwiimveliso ezininzi kufuneka kuncitshiswe, kuba incasa/ivumba le-AA liyaziwa ngokuchaphazela incasa yezinye iziselo ezipakishiweyo kunye nokutya. Kukho iindlela ezininzi ezixeliweyo zokunciphisa izixa ze-AA eziveliswe ngexesha lokunyibilika kunye nokusetyenzwa kwe-PET. Enye indlela kukwandisa iimeko zokusetyenzwa phantsi kwazo izikhongozeli zePET zenziwa. Ezi ziguquko, ezibandakanya ukushisa okunyibilikayo, ixesha lokuhlala, kunye nesantya sokucheba, kuboniswe ukuba kuchaphazela kakhulu isizukulwana se-AA. Indlela yesibini kukusetyenziswa kweeresin ze-PET ezilungiselelwe ngokukodwa ukunciphisa ukuveliswa kwe-AA ngexesha lokwenziwa kwezikhongozeli. Ezi resins zaziwa kakhulu ngokuba ''ibakala lamanzi i-PET resins''. Indlela yesithathu kusetyenziso lwezongezo ezaziwa ngokuba zii-acetaldehyde scavenging agents.

I-AA scavengers yenzelwe ukusebenzisana nayo nayiphi na i-AA eyenziwa ngexesha lokucubungula i-PET. La ma-scavengers awanciphisi ukuthotywa kwe-PET okanye ukubunjwa kwe-acetaldehyde. Banga; nangona kunjalo, nciphisa ubungakanani beAA ekwaziyo ukusasazeka ngaphandle kwesikhongozeli kwaye ngaloo ndlela inciphise naziphi na iziphumo kwiziqulatho ezipakishiweyo. Ukusebenzisana kwee-arhente zokuxhwila kunye ne-AA kumiselwe ukuba kwenzeke ngokweendlela ezintathu ezahlukeneyo, ngokuxhomekeke kwisakhiwo semolekyuli somkhwezeli othile. Uhlobo lokuqala lomatshini wokuxhwitha kukusabela kweekhemikhali. Kule meko i-AA kunye ne-agent ehlanjululwayo isabela ukwenza i-chemical bond, idala ubuncinane imveliso enye entsha. Kuhlobo lwesibini lwendlela yokulahla i-complex ehlanganisiweyo yenziwa. Oku kwenzeka xa i-AA ingena kwi-cavity yangaphakathi ye-agent e-scavening kwaye ibanjwe kwindawo ye-hydrogen bonding, okubangelwa ukuxutywa kwee-molecule ezimbini ezihlukeneyo ezidityaniswe ngeendlela zesibini zeekhemikhali. Uhlobo lwesithathu lwendlela yokulahla iquka ukuguqulwa kwe-AA ibe kolunye uhlobo lweekhemikhali ngokusebenzisana kwayo ne-catalyst. Ukuguqulwa kwe-AA ibe yikhemikhali eyahlukileyo, efana ne-acetic acid, inokunyusa indawo yokubilisa yomfuduki kwaye ngaloo ndlela inciphise amandla ayo okuguqula incasa yokutya okupakishiweyo okanye isiselo.


Ixesha lokuposa: May-10-2023