Kokubili ama-ketone nama-ester kungamaqembu amabili abalulekile kakhulu ekusebenzeni kwe-organic chemistry. Atholakala ezinhlobonhlobo eziningi zamakhemikhali e-organic futhi adlala indima ebalulekile ezinqubweni eziningi ze-biological kanye ne-chemical. Naphezu kokufana kwawo, izici zawo kanye nokuziphatha kwawo kuhlukile kakhulu. Ake sihlole ukuthi ayini ama-ketone nama-ester, ahluke kanjani, afana kanjani, nokuthi asho ukuthini ku-chemistry kanye ne-biology.
Ama-ketone ayisigaba samakhemikhali e-organic aqukethe iqembu elisebenzayo le-carbonyl (C=O) phakathi kwe-molecule. Ama-ketone anamaqembu amabili e-alkyl noma e-aryl anamathele ku-carbonyl carbon. Elilula kulawa yi-acetone, enefomula (CH3)2CO. Akhiqizwa ngokuqhekeka kwamafutha emzimbeni. Aziwa nangokuthi imizimba ye-ketone, ama-ketone angamakhemikhali akhiqizwa lapho umzimba wakho uqala ukuqhekeka amafutha esikhundleni sama-carbohydrate ukuze uthole amandla.
Ama-ketone akhiwa ngama-fatty acid esibindini bese ekhishwa egazini, lapho angasetshenziswa khona njengomthombo wamandla wamaseli nezitho zomzimba. Uma umzimba use-ketosis, uthembele kuma-ketone njengomthombo wawo oyinhloko wamandla, hhayi ku-glucose, yingakho ukudla kwe-ketogenic kuye kwathandwa kakhulu eminyakeni yamuva nje. Kodwa-ke, ama-ketone awakhiqizwa kuphela ngesikhathi sokuzila ukudla noma ngesikhathi sokudla kwe-ketogenic. Angakhiqizwa nalapho umzimba ucindezelekile, njengasesikhathini sokuzivocavoca okunzima, noma lapho kunokuntuleka kwe-insulin emzimbeni, okungenzeka kubantu abanesifo sikashukela.
Ama-ketone amathathu akhiqizwa ngesikhathi se-ketosis: i-acetone, i-acetoacetate, kanye ne-beta-hydroxybutyrate (BHB). Phakathi kwawo, i-acetone iyi-ketone ekhishwa emzimbeni ngokuphefumula, ekhiqiza iphunga elimnandi noma elifana nezithelo emoyeni, elaziwa ngokuthi "ukuphefumula kwe-keto". Lokhu kungaba uphawu lokuthi umzimba wakho ungene esimweni se-ketosis. I-Acetoacetate, enye i-ketone, ikhiqizwa esibindini futhi isetshenziswa amangqamuzana omzimba ukuthola amandla. Kodwa-ke, iphinde iguqukele ku-BHB, uhlobo oluvame kakhulu lwe-ketone egazini ngesikhathi se-ketosis. I-BHB ingawela kalula isithiyo segazi nobuchopho, ngaleyo ndlela inike amandla ubuchopho futhi ingathuthukisa ukucaca kwengqondo nokugxila.
Ama-Esters ayizinhlanganisela eziphilayo ezinomsebenzi we-RCOOR, lapho i-R ne-R' kuyiqembu lezinto eziphilayo. Ama-Esters akheka lapho ama-carboxylic acid kanye notshwala kusabela ngaphansi kwezimo ze-asidi futhi kususa i-molecule yamanzi. Avame ukutholakala emafutheni abalulekile kanye nezithelo eziningi. Isibonelo, iphunga elikubhanana ovuthiwe livela ku-ester ebizwa ngokuthi i-isoamyl acetate. Ama-Esters anezakhiwo ezihlukile eziwenza abe yigugu ezimbonini ezahlukene.
1. Amaphunga
Enye yezindlela ezivame ukusetshenziswa ngayo ama-ester kusezinukweni nasemakhafuleni ngenxa yephunga lawo elimnandi, elinoshukela nelimnandi, futhi ayasiza ekuthuthukiseni iphunga lomkhiqizo, okwenza ukhange kakhulu kubasebenzisi.
2. Ukunambitheka kokudla
Isakhiwo samakhemikhali esiyingqayizivele sama-ester siwavumela ukuthi aveze iphunga lezithelo nezimbali, ngakho-ke ama-ester asetshenziswa nasembonini yokudla, ikakhulukazi ekunambithekeni. Avame kakhulu ekudleni okuningi okuhlanganisa amaswidi, izinto ezibhakiwe kanye neziphuzo. Empilweni yansuku zonke, ama-ester asetshenziswa ekukhiqizeni ukunambitheka okwenziwa futhi abe yizithako eziyisisekelo ekudleni okuningi.
3. Ipulasitiki
Njengama-plasticizer, ama-ester enza amapulasitiki aguquguquke futhi aqine. Ngakho-ke ama-ester asetshenziswa ekukhiqizweni kwamapulasitiki ahlukahlukene, futhi asiza nasekuvimbeleni ukuthi amapulasitiki angabi buthakathaka ngokuhamba kwesikhathi. Lokhu kubalulekile emikhiqizweni eqinile njengezingxenye zezimoto noma amadivayisi ezokwelapha.
4. Isinyibilikisi
Ngoba ama-ester angancibilikisa izinto eziphilayo ezifana namafutha, ama-resin namafutha. Ngakho-ke, ama-ester ayasiza ezimbonini eziningi njengezixazululo zokuncibilikisa ezinye izinto. Ama-ester ayizixazululo ezinhle, okwenza abe usizo ekukhiqizeni upende, ama-varnish kanye ne-adhesive.
Ngokuqhathanisa ama-ketone nama-ester, singathola ukuthi umehluko phakathi kwama-ketone nama-ester utholakala kakhulu kulezi zici ezilandelayo:
1. Umehluko omkhulu phakathi kwama-ketone nama-ester utholakala kakhulu esakhiweni samakhemikhali. Iqembu lama-ketone le-carbonyl litholakala phakathi nochungechunge lwekhabhoni, kanti iqembu lama-ester le-carbonyl litholakala ekugcineni kochungechunge lwekhabhoni. Lo mehluko wesakhiwo uholela ekwehlukeni kwezakhiwo zawo zomzimba nezamakhemikhali.
●Ama-Ketone ayizinto eziphilayo ezineqembu le-carbonyl elakhiwe yi-athomu ye-oxygen ehlanganiswe kabili ne-athomu ye-carbon etholakala phakathi nochungechunge lwe-carbon. Ifomula yawo yamakhemikhali yi-R-CO-R', lapho u-R no-R' kuyi-alkyl noma i-aryl. Ama-Ketone akhiwa ngokushiswa kwama-alcohol esibili noma ukuqhekeka kwama-carboxylic acid. Aphinde abhekane ne-keto-enol tautomerism, okusho ukuthi angaba khona kokubili ezinhlotsheni ze-ketone kanye ne-enol. Ama-Ketone avame ukusetshenziswa ekukhiqizweni kwezinyibilikisi, izinto ze-polymer kanye nemithi.
●Ama-Esters ayizinhlanganisela eziphilayo ezineqembu le-carbonyl ekugcineni kochungechunge lwekhabhoni kanye neqembu le-R elixhunywe kwi-athomu ye-oxygen. Ifomula yawo yamakhemikhali yi-R-COOR', lapho i-R kanye ne-R' kuyi-alkyl noma i-aryl. Ama-Esters akhiwa ukusabela kwama-carboxylic acid nama-alcohols lapho kukhona i-catalyst. Anephunga elimnandi lezithelo futhi avame ukusetshenziswa ekukhiqizeni amakha, ama-essence kanye nama-plasticizer.
2.Umehluko osobala kakhulu phakathi kwama-ketone nama-ester iphuzu lawo lokubila. Iphuzu lokubila lama-ketone liphakeme kunelama-ester ngoba anamandla amakhulu phakathi kwama-molecule. Iqembu le-carbonyl ku-ketone lingakha izibopho ze-hydrogen nama-molecule e-ketone aseduze, okuholela emandleni aqinile phakathi kwama-molecule. Ngokuphambene nalokho, ama-ester anamandla abuthakathaka phakathi kwama-molecule ngenxa yokungakwazi kwama-athomu e-oxygen eqenjini le-R ukwakha izibopho ze-hydrogen nama-molecule e-ester aseduze.
3.Ngaphezu kwalokho, ukusabela kwama-ketone nama-ester kuhlukile. Ngenxa yokuba khona kwamaqembu amabili e-alkyl noma e-aryl kuzo zombili izinhlangothi zeqembu le-carbonyl, ama-ketone asabela kakhulu kunama-ester. La maqembu anganikela ngama-electron ku-carbonyl, okwenza kube lula ukuthi ahlaselwe yi-nucleophilic. Ngokuphambene nalokho, ama-ester awasabela kakhulu ngenxa yokuba khona kweqembu le-alkyl noma le-aryl ku-athomu ye-oxygen. Leli qembu linganikela ngama-electron ku-athomu ye-oxygen, okwenza kube lula ukuthi ahlaselwe yi-nucleophilic.
4. Ngenxa yezakhiwo ezahlukene, amaphuzu abilayo kanye nokusebenza kabusha kwama-ketone nama-ester, umehluko ekusetshenzisweni kwawo uyanqunywa. Ama-ketone avame ukusetshenziswa ekukhiqizeni izinyibilikisi, izinto ze-polymer kanye nemithi, kuyilapho ama-ester evame ukusetshenziswa ekukhiqizeni amakha, ukunambitheka kanye nama-plasticizer. Ama-ketone asetshenziswa futhi njengezengezo zikaphethiloli kuphethiloli, kuyilapho ama-ester esetshenziswa njengezinto zokugcoba emishinini.
Sesivele siyayazi imininingwane yama-ketone nama-ester, ngakho-ke uyini umehluko phakathi kwama-ketone, ama-ester nama-ether?
Okokuqala, sidinga ukwazi ukuthi iyini i-ether? i-ether iqukethe i-athomu ye-oksijini ehlanganiswe nama-athomu amabili e-carbon. Ayinhlanganisela eyaziwa ngezakhiwo zayo zezidakamizwa. i-ether ngokuvamile ayinambala, ayixinene kangako kunamanzi, futhi iyizinyibilikisi ezinhle zezinye izinhlanganisela eziphilayo ezifana namafutha namafutha. Zisetshenziswa futhi njengezithasiselo zikaphethiloli ezinjinini zikaphethiloli ukuthuthukisa ukusebenza kwezinjini.
Ngemva kokuqonda izakhiwo zamakhemikhali kanye nokusetshenziswa kwalezi zinto ezintathu, singazi ngokucacile ukuthi umehluko phakathi kwama-ketone, ama-ester kanye ne-ether uhlanganisa izici ezimbili ezilandelayo:
1. Omunye wemehluko ophawulekayo esingawuthola phakathi kwama-ketone, ama-ester, kanye ne-ether amaqembu awo asebenzayo. Ama-ketone aqukethe amaqembu e-carbonyl, ama-ester aqukethe ukuxhumana kwe-ester-COO, kanti ama-ether awaqukethe amaqembu asebenzayo. Ama-ketone nama-ester abelana ngokufana okuthile ngezakhiwo zamakhemikhali. Womabili la ma-compounds angama-polar futhi angakha izibopho ze-hydrogen namanye ama-molecule, kodwa izibopho ze-hydrogen kuma-ketone zinamandla kunalezo ezikuma-ester, okuholela ekubileni okuphezulu.
2.Omunye umehluko obalulekile ukuthi lezi ezintathu zinezindlela ezahlukene zokusebenzisa
(1)Enye yezindlela ezivame kakhulu zokusebenzisa ama-ketones njenge-solvent yama-resin, ama-waxes, namafutha. Asetshenziswa futhi ekukhiqizweni kwamakhemikhali amahle, imithi kanye namakhemikhali ezolimo. Ama-ketone anjenge-acetone asetshenziswa ekukhiqizweni kwepulasitiki, imicu kanye nopende.
(2)Ama-Ester avame ukusetshenziswa embonini yokudla kanye nezimonyo ngenxa yephunga lawo elimnandi kanye nokunambitheka. Asetshenziswa futhi njengezinyibilikisi zama-inki, ama-varnish kanye nama-polymer. Ama-Ester asetshenziswa nasekukhiqizweni kwama-resin, ama-plasticizer kanye nama-surfactants.
(3)I-ether inezindlela eziningi zokusetshenziswa ngenxa yezakhiwo zayo ezihlukile. Zisetshenziswa njengezinyibilikisi, izibulala-zinhlungu kanye nama-surfactant, phakathi kwezinye. Embonini yezolimo, zisetshenziswa njengezinto zokuhlanza ukuvikela izitshalo ezigciniwe ezinambuzaneni nasezifweni zesikhunta. I-ether isetshenziswa nasekukhiqizweni kwama-resin e-epoxy, izinamathiseli kanye nezinto zokumboza.
Ama-ketone nama-ester anezisetshenziswa ezibanzi kumakhemikhali ezinto eziphilayo futhi ayakha izinqubo eziningi zezimboni. Isibonelo, ama-ketone asetshenziswa njengezinto ezincibilikisayo, ekukhiqizweni kwemithi nama-polymer. Ama-ester, ngakolunye uhlangothi, asetshenziswa embonini yamakha nezimonyo, njengezinto zokunambitha embonini yokudla, njengezinto ezincibilikisayo, kanye nasemapendeni nasezimbozweni.
Isikhathi sokuthunyelwe: Juni-14-2023
