Ngesikhathi sokwenziwa kwe-malonic acid, ukuqapha umkhawulo wobuningi kwembula ukuthi ukuguqulwa kube yi-diethyl malonate noma i-monoethyl malonate sekufinyelele esiphethweni sayo. Ukulinganisa okuqhubekayo kusekela ukulungiswa kwenqubo eqondile, ukuvimbela ukungahambisani kweqembu kanye nokunciphisa imfucuza yezinto zokusetshenziswa.
Ukulinganiswa kobuningi obuphakathiihlinzeka ngokulandelela okuqhubekayo kwesikhathi sangempela kwenqubekela phambili yokusabela kwe-esterification, isusa ukusampula ngesandla kanye nokungacaci kwe-endpoint. Ukulinganiswa kobuningi obuphakathi kokusabela kwamakhemikhali kuvumela ukulungiswa kokulawula okusheshayo, okuzenzakalelayo, kunciphisa ukusetshenziswa kwamandla kanye nokuchitha. Izifundo zezimboni zifakazela ukuthi ukuhlanganiswa kwemitha yobuningi obuphakathi kwezinqubo zamakhemikhali kuphakamisa ukuvumelana komkhiqizo ngaphezu kwama-95%, ngokusho kocwaningo lwamuva lwenqubo. Lokhu kuthuthukiswa kuqhuba ukusebenza kahle kwamandla ekukhiqizweni kwamakhemikhali ngenkathi kusekelwa izidingo zekhwalithi eziqinile zokwenziwa kwe-diethyl malonate kanye nokwenziwa kwe-monoethyl malonate.
Isitshalo se-Diethyl Malonate
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Ukubuka Konke Kokugeleza Kwenqubo Yokuqinisekisa
I-Malonic acid isabela ne-ethanol engamanzi ngaphansi kokulawulwa okuqondile kokushisa, ikhiqiza i-diethyl malonate kanye ne-monoethyl malonate nge-esterification. Isigaba ngasinye sibonisa izinguquko ezihlukile zobuningi—ubuningi besisombululo se-reactant buyancipha njengoba ukuguqulwa kuqhubeka. Ukulinganiswa kobuningi obungaphakathi kokusabela kwamakhemikhali kunikeza ukulandelela okuqhubekayo kwalezi zinguquko. Ukutholwa kwesikhathi sangempela komkhawulo wobuningi kuphawula ukuphela kokusabela kumakhemikhali.
Ukuthuthukiswa kwenqubo, okufezwa ngokuqapha umkhawulo wobuningi obuphakathi, ukunciphisa ukucubungula ngokweqile kanye nokusetshenziswa kwezinto zokusetshenziswa. Ukulinganiswa okuqhubekayo komugqa kukhulisa isivuno somkhiqizo futhi kuqinisekisa ukusebenza kahle kwamandla ekukhiqizweni kwamakhemikhali. Lokhu kusekela ukwakheka kwe-diethyl malonate okuphezulu kanye nokusetshenziswa kwe-monoethyl malonate, kusebenzisa izakhiwo zamakhemikhali ze-malonic acid ngokulawula inqubo okunembile.
Izinselele Ekulinganisweni Kobuningi/Ukugxila Okuphakathi
Izingxube zokusabela ekuqinisekisweni kwe-ester ziyashintshashintsha ekubonakaleni nasekuxineni ngenxa yamazinga okuguqulwa kwe-malonic acid ahlukahlukene. Ukulinganiswa kwemitha yobuningi obuqondile kudinga isinxephezelo esiqinile sokushisa, njengoba ukushintsha ngakunye kwe-1°C kungashintsha ubuningi besisombululo cishe ngo-0.15–0.2 kg/m³, okwenza kube nzima ukuthola indawo yokuphela kokusabela.
Ukuba khona komkhiqizo olandelanayo kunciphisa ukuzwela kokulinganisa indawo yokugcina, okuthinta ukunemba kokuqapha umkhawulo wobuningi. Ukusampula ngesandla ekuhlanganisweni kwe-diethyl malonate kwethula amaphutha afinyelela ku-3%, ngokubambezeleka okuvimbela ukusayinwa kokuqedwa kokusabela ngokushesha kanye nokulungiswa kwenqubo ngesikhathi sangempela.
I-Diethyl malonate
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Izinzuzo Zokuhlanganisa Amamitha Obuningi Obungaphakathi
Ukulinganiswa kwemitha yobuningi obuphakathi kuqinisekisa ukutholwa kwe-endpoint yokusabela okuhlala njalo, ngesikhathi sangempela ngesikhathi sokwenziwa kwe-malonic acid kanye ne-diethyl malonate. Ukusebenzisa imitha yobuningi obuphakathi kwezinqubo zamakhemikhali kunciphisa ama-off-spec batches, okunikeza ukuqapha okuqhubekayo kokuguqulwa kwamakhemikhali ekuqinisekisweni kwe-esterization kusetshenziswa i-malonic acid kanye ne-anhydrous ethanol. Ukulungiswa kwenqubo okuzenzakalelayo kugcina i-endpoint efanele yokusabela kumakhemikhali, kunciphisa ukuphambuka kusuka ku-stoichiometry yomkhiqizo oyifunayo.
Ukuqapha umkhawulo wobuningi kwenza kube lula ukuhlonza izinkomba zokuqedwa kokusabela ngokushesha, kunciphisa ukubambezeleka okuhlobene nokusampula ngesandla. Ukulinganiswa kobuningi obuphakathi kokusabela kwamakhemikhali kunciphisa ngqo ukucutshungulwa ngokweqile. Lokhu kunciphisa izinto zokusetshenziswa ezingeziwe futhi kunciphisa ukulahlekelwa kwesivuno, njengoba kuboniswe ekuhlanganisweni kwe-monoethyl malonate, lapho ukulandelela ubuningi kunciphisa imfucuza ngaphezu kuka-10%. Ukulawulwa kokuphela kwento okulungiselelwe kunciphisa ukusetshenziswa kwamandla ngo-8-12% ngesikhathi sokusetshenziswa kwe-diethyl malonate ngokusebenzisa imijikelezo yokushisa nokupholisa enembile.
Inani lamamitha Okugxila/Ubuningi be-Lonnmeter
Amamitha okuqina angaphakathi kwe-Lonnmeter aletha ukunemba okungu-±0.001 g/cm³, okubalulekile ekutholakaleni kokuphela kokusabela okuthembekile ekuqinisekisweni kwe-ester. Ukulinganisa ukuqina kwesikhathi sangempela okunembile kusekela ukuguqulwa kwe-malonic acid ibe yi-diethyl malonate kanye ne-monoethyl malonate, okuhlanganisa izilinganiso ezibalulekile ekuhlanganisweni kwe-diethyl malonate kanye nokuhlanganiswa kwe-monoethyl malonate.
Amayunithi aklanyelwe i-ethanol engenamanzi embonini ahlala eqinile ngaphansi kwezimo ezigqwalisayo nezinamandla okukhipha amanzi amaningi. Amaseli okugeleza kwensimbi engagqwali aqinile aqinisekisa ukuqina; izingxenye ezimanziswe yinzwa ziyamelana namakhemikhali ekusetshenzisweni kwe-malonic acid ekuhlanganisweni nasekusetshenzisweni kwe-ethanol engenamanzi.
Cela ikhotheshini yamamitha okuqina angaphakathi e-Lonnmeter ukuze uthole ukusabela kwamakhemikhali okudinga ukuqapha okuqinile komkhawulo wokuqina. Finyelela ekutholakaleni kokuphela kokusabela okunembile kwe-malonic acid, i-diethyl malonate, kanye nokwakheka kwe-monoethyl malonate usebenzisa amathuluzi angaphakathi athuthukile kuphela—akukho software noma izinhlelo zokulawula ezifakiwe.
Isikhathi sokuthunyelwe: Jan-27-2026
