iindaba

Kwishishini leekhemikhali, kukho iimveliso ezimbini ezinamagama afanayo kakhulu, ezizezi i-glyoxylic acid kunye ne-glycolic acid. Abantu abaninzi abakwazi ukuzahlula. Namhlanje, makhe sijonge ezi mveliso zimbini kunye. I-Glyoxylic acid kunye ne-glycolic acid ziikhompawundi ezimbini ze-organic ezinomahluko omkhulu kwisakhiwo kunye neempawu. Umahluko wazo ulele kakhulu kwisakhiwo se-molecular, iimpawu zekhemikhali, iimpawu zomzimba kunye nokusetyenziswa, ngolu hlobo lulandelayo:

Ulwakhiwo kunye nokwakheka kweemolekyuli kwahlukile

Lo ngowona mahluko uphambili phakathi kwezi zimbini, nto leyo echaza ngokuthe ngqo umahluko kwezinye iimpawu.

I-Glyoxylic acid

I-CAS 298-12-4, enefomula yekhemikhali i-C2H2O3 kunye nefomula yolwakhiwo i-HOOC-CHO, iqulethe amaqela amabini asebenzayo - iqela le-carboxyl (-COOH) kunye neqela le-aldehyde (-CHO), kwaye ikwiklasi yeekhompawundi ze-aldehyde acid.

I-Glycolic acid

I-CAS 79-14-1, enefomula yekhemikhali i-C2H4O3 kunye nefomula yolwakhiwo i-HOOC-CH2OH, iqulethe amaqela amabini asebenzayo - iqela le-carboxyl (-COOH) kunye neqela le-hydroxyl (-OH), kwaye ikwiklasi yeekhompawundi ze-α-hydroxy acid.

Iifomyula zeemolekyuli zezi zimbini zahlukile ngeeathom ezimbini zehydrogen (H2), kwaye umahluko kumaqela asebenzayo (iqela le-aldehyde vs. iqela le-hydroxyl) luphawu oluphambili.

Iimpawu ezahlukeneyo zeekhemikhali

Umahluko kumaqela asebenzayo ukhokelela kwiipropati zeekhemikhali ezahlukeneyo ngokupheleleyo phakathi kwezi zimbini:

Iimpawu zei-asidi ye-glyoxylic(ngenxa yokubakho kwamaqela e-aldehyde):

Ineempawu ezinamandla zokunciphisa: iqela le-aldehyde linyibilika lula kwaye lingenza i-silver mirror reaction kunye ne-silver ammonia solution, liphinde liphendule nge-copper hydroxide suspension esandula ukulungiswa ukuze lenze i-brick-red precipitate (i-cuprous oxide), kwaye liphinde linyibilike libe yi-oxalic acid zii-oxidants ezifana ne-potassium permanganate kunye ne-hydrogen peroxide.

Amaqela e-Aldehyde anokuhlangabezana neempendulo ezongezelelweyo: umzekelo, anokusabela kunye ne-hydrogen ukwenza i-glycolic acid (olu luhlobo lobudlelwane botshintsho phakathi kwezi zimbini).

Iimpawu ze-glycolic acid (ngenxa yokubakho kwamaqela e-hydroxyl):

Amaqela e-hydroxyl aphila ngokwe-nucleophilic: anokungenelwa ziimpendulo ze-intramolecular okanye intermolecular esterification kunye namaqela e-carboxyl ukuze enze ii-ester ezijikelezayo okanye ii-polyesters (ezifana ne-polyglycolic acid, into ebolayo ye-polymer).

Amaqela e-hydroxyl anokuxiliswa: nangona kunjalo, ubunzima be-oxidation buphezulu kunobo bamaqela e-aldehyde kwi-glyoxylic acid, kwaye i-oxidant enamandla (efana ne-potassium dichromate) iyadingeka ukuze kuxoxwe amaqela e-hydroxyl kumaqela e-aldehyde okanye amaqela e-carboxyl.

I-asidi yeqela le-carboxyl: Zombini ziqulathe amaqela e-carboxyl kwaye zine-asidi. Nangona kunjalo, iqela le-hydroxyl le-glycolic acid linefuthe elibuthathaka lokunika i-electron kwiqela le-carboxyl, kwaye i-asidi yalo ibuthathaka kancinci kuneye-glycolic acid (i-glycolic acid pKa≈3.18, i-glycolic acid pKa≈3.83).

Iimpawu ezahlukeneyo zomzimba

Imeko kunye nokunyibilika:

Inyibilika lula emanzini nakwizinto ezinyibilikayo ze-polar organic (ezifana ne-ethanol), kodwa ngenxa yomahluko kwi-molecular polarity, ukunyibilika kwazo kwahlukile kancinci (i-glyoxylic acid ine-polarity enamandla kunye nokunyibilika okuphezulu kancinci emanzini).

Indawo yokunyibilika

Iqondo lokunyibilika kwe-glyoxylic acid limalunga nama-98℃, ngelixa elo le-glycolic acid limalunga nama-78-79℃. Umahluko uvela kumandla aphakathi kweemolekyuli (iqela le-aldehyde le-glyoxylic acid linamandla aqinileyo okwenza iibhondi ze-hydrogen kunye neqela le-carboxyl).

Usetyenziso olwahlukileyo

I-Glyoxylic acid

Isetyenziswa kakhulu kwishishini lokwenziwa kwezinto eziphilayo, njengokwenziwa kwe-vanillin (incasa), i-allantoin (isixhobo samayeza esikhuthaza ukuphiliswa kwamanxeba), i-p-hydroxyphenylglycine (isixhobo samayeza esilwa neentsholongwane), njl. Ingasetyenziswa njengesongezelelo kwizisombululo ze-electroplating okanye kwizithambiso (isebenzisa iipropati zayo zokunciphisa kunye ne-antioxidant). Iimveliso zokhathalelo lweenwele: Njengesithako sokulungisa iinwele, inceda ukulungisa imicu yeenwele eyonakeleyo kwaye iphucule ukukhazimla kweenwele (kufuneka idityaniswe nezinye izithako ukunciphisa ukucaphuka).

I-Glycolic acid

Njenge-α-hydroxy acid (AHA), ukusetyenziswa kwayo okuphambili kukukwicandelo leemveliso zokhathalelo lolusu. Isebenza njengesithako sokukhupha ulusu (ngokunyibilikisa izinto ezidibanisayo phakathi kwe-stratum corneum yolusu ukukhuthaza ukukhuhla ulusu olufileyo), ukuphucula iingxaki ezifana nolusu olurhabaxa kunye namabala e-acne. Ukongeza, ikwasetyenziswa kwishishini lempahla (njenge-bleaching agent), ii-cleaners (zokususa isikali), kunye nokuhlanganiswa kweeplastiki ezibolayo (i-polyglycolic acid).

Umahluko ophambili phakathi kwezi zimbini uvela kumaqela asebenzayo: i-glyoxylic acid ineqela le-aldehyde (elineempawu zokunciphisa ezinamandla, ezisetyenziswa kwi-organic synthesis), kwaye i-glycolic acid ineqela le-hydroxyl (linokuqiniswa, lisetyenziswe kwiinkalo zokhathalelo lolusu kunye nezixhobo). Ukususela kwisakhiwo ukuya kwindalo ukuya kwisicelo, zonke zibonisa umahluko omkhulu ngenxa yolu mahluko luphambili.