Oxalic acidhmoov yog xim tsis muaj pob tshab siv lead ua los yog hmoov, thiab nws cov qauv siv lead ua muaj ob hom, xws li Hom (pob zeb diamond) thiab Hom (monoclinic). Nws tsis muaj ntxhiab tsw thiab qaub saj. Oxalic acid tsim los ntawm oxidation tsis muaj ntxhiab, thaum oxalic acid tsim los ntawm kev sib txuas tsis muaj ntxhiab. 150 ~ 160 degree sublimation. Nws tuaj yeem ua rau huab cua kub qhuav. 1g yog soluble hauv 7mL dej, 2mL ntawm boiling dej, 2.5mL ntawm ethanol, 1.8ml ntawm boiling ethanol, 100mL ntawm ether, 5.5mL ntawm glycerol, thiab insoluble nyob rau hauv benzene, chloroform thiab roj av.
Kev siv oxalic acid hmoov:
1.As txo tus neeg sawv cev:
Hauv kev lag luam organic synthesis, nws yog siv los tsim hydroquinone, pentaerythritol, cobalt oxalate, nickel oxalate, gallic acid thiab lwm yam khoom siv tshuaj.
2.Kev lag luam yas yog siv los tsim PVC, amino plastics, urea-formaldehyde plastics, xim chips, thiab lwm yam.
3.Dye kev lag luam yog siv los tsim ntsev puag magenta, thiab lwm yam.
Hauv kev lag luam luam ntawv thiab dyeing, acetic acid tuaj yeem siv los ua xim tsim kev pab thiab tshuaj dawb rau cov xim dyes.
Kev lag luam kws tshuaj yog siv los tsim aureomycin, oxytetracycline, tetracycline, streptomycin thiab ephedrine.
4. Tsis tas li ntawd, oxalic acid kuj tuaj yeem siv los tsim ntau yam oxalates, oxalates, oxalamides thiab lwm yam khoom, nrog rau cov khoom loj tshaj plaws ntawm diethyl oxalate, sodium oxalate thiab calcium oxalate.
5.Antimony oxalate tuaj yeem siv los ua mordant, thiab ammonium ferric oxalate yog reagent rau luam ntawv blueprints.
6.Xev tshem tawm muaj nuj nqi.
Oxalic acid tuaj yeem siv los tshem tawm cov xeb: yuav ib lub raj mis ntawm oxalic acid los ntawm lub khw muag tshuaj reagents, nqa ib co ntawm nws, npaj ib tug tov nrog dej sov, thiab smear rau ntawm xeb stain. Tom qab ntawd so nrog metallographic abrasive ntawv, thiab thaum kawg tshuaj tsuag xim. Feem ntau, cov khw muag khoom oxalic acid kuj muag qee cov cuab yeej kho mob thiab cov cuab yeej iav.
(Kev ceev faj: ceev faj thaum siv. Oxalic acid muaj zog corrosivity rau stainless hlau. Oxalic acid nrog siab concentration kuj yooj yim rau corrode tes. Thiab cov kua qaub oxalate generated muaj ib tug siab solubility, tab sis nws muaj ib tug tej yam toxicity. Tsis txhob noj nws. Tom qab kev sib cuag nrog oxalic acid, ntxuav nws nrog dej hauv lub sijhawm.)
chemical khoom:
Oxalic acid, tseem hu ua oxalic acid, yog dav pom nyob rau hauv zaub mov. Oxalic acid yog cov xim tsis muaj kob uas tsis muaj kob, uas yooj yim soluble hauv dej tab sis tsis nyob hauv cov kuab tshuaj organic xws li ether,
Oxalate muaj kev sib koom tes zoo thiab yog lwm hom hlau chelate tus neeg sawv cev hauv zaub mov. Thaum oxalic acid ua ke nrog qee cov alkaline ntiaj teb hlau ntsiab lus, nws solubility txo qis heev, piv txwv li, calcium oxalate yuav luag insoluble hauv dej. Yog li ntawd, lub xub ntiag ntawm oxalic acid muaj kev cuam tshuam zoo rau bioavailability ntawm cov zaub mov tseem ceeb; Thaum oxalic acid ua ke nrog qee cov hlau hloov pauv hloov pauv, cov txheej txheem soluble yog tsim los ntawm kev sib koom tes ntawm oxalic acid, thiab nws cov solubility tau nce ntau.
Oxalic acid pib sublimate ntawm 100 degree, sai sublimates ntawm 125 degree, sublimates nyob rau hauv loj qhov ntau ntawm 157 degree, thiab pib decompose.
Nws tuaj yeem cuam tshuam nrog alkali thiab tuaj yeem dhau esterification, acyl halogenation thiab amidation. Txo cov tshuaj tiv thaiv thiab cov tshuaj tiv thaiv decarboxylation tuaj yeem tshwm sim thaum cua sov. Anhydrous oxalic acid yog hygroscopic. Oxalic acid tuaj yeem tsim cov dej-soluble complexes nrog ntau cov hlau.
Acidic:
Oxalic acid yog ib qho tsis muaj zog acid. Nws thawj qhov kev txiav txim ionization tas li Ka1=5.9 × 10-2, secondary ionization tas li Ka2=6.4 × 10-5. Nws muaj acid permeability. Nws tuaj yeem cuam tshuam nrog alkali, discolor qhov taw qhia, thiab hnov mob nrog carbonate kom tso carbon dioxide.
Piv txwv li:
H2C2O4plus Na2CO3=Na2C2O4plus CO2↑ Ntxiv H2O
H2C2O4ntxiv Zn=ZnC2O4ntxiv H2↑
Reductibility:
Oxalate muaj zog oxidation-txo cov cuab yeej, thiab tuaj yeem yooj yim oxidized rau carbon dioxide thiab dej thaum cuam tshuam nrog oxidants. Nws tuaj yeem ploj mus rau cov kua qaub potassium permanganate (KMnO4) thiab txo nws mus rau 2 valent manganese ion. Cov tshuaj tiv thaiv no yog siv los ua ib txoj hauv kev los txiav txim siab qhov concentration ntawm poov tshuaj permanganate hauv kev tsom xam kom muaj nuj nqis. Oxalic acid kuj tseem tuaj yeem ntxuav cov cwj mem stains ntawm daim ntaub.
2 KMnO4plus 5 H2C2O4plus 3 H2YOG4=K2YOG4plus 2 MnSO4plus 10 CO2↑ 8 H2O
H2C2O4plus NaClO=NaCl plus 2CO2↑ Ntxiv H2O
Instability:
Oxalic acid yuav decompose rau hauv carbon dioxide, carbon monoxide thiab dej ntawm 189.5 degree los yog nyob rau hauv lub xub ntiag ntawm concentrated sulfuric acid.
H2C2O4=CO2↑ + CO↑ + H2O
Lub chaw kuaj mob tuaj yeem siv cov tshuaj tiv thaiv no los tsim cov pa roj carbon monoxide.
Ammonium hydrogen oxalate yog decomposed rau hauv carbon dioxide, carbon monoxide, ammonia thiab dej ntawm 200 degree.
Toxicity:
Oxalic acid yog tshuaj lom, muaj qhov ua rau khaus thiab corrosive rau ntawm daim tawv nqaij thiab mucous daim nyias nyias, thiab yooj yim absorbed los ntawm daim tawv nqaij thiab mucous daim nyias nyias los ua lom. Qhov siab tshaj plaws tso cai nyob rau hauv huab cua yog 1mg / m3.
Cov tshuaj tiv thaiv Esterification:
Acetic acid tuaj yeem hnov mob nrog cawv los ua ester, piv txwv li, oxalic acid reacts nrog ethanol los tsim diethyl oxalate.
Synthesis txoj kev ntawm oxalic acid hmoov:
1. Ethylene glycol oxidation txoj kev yog tau los ntawm kev siv ethylene glycol ua raw khoom thiab oxidizing nrog huab cua nyob rau hauv lub xub ntiag ntawm nitric acid thiab sulfuric acid.
2. Cov txheej txheem oxidation ntawm propylene oxidation yog ua nyob rau hauv ob kauj ruam. Thawj kauj ruam yog oxidation nrog nitric acid los hloov propylene rau hauv - Nitrolactic acid; Tom qab ntawd, oxalic acid yog tau los ntawm kev ntxiv catalytic oxidation. Hauv theem ob, cov kua qaub sib xyaw kuj tuaj yeem siv los ua oxidant. Tag nrho cov txiaj ntsig ntawm kev lag luam oxalic acid dihydrate ua los ntawm propylene oxidation yog ntau tshaj 90 feem pua.
Cov khoom siv raw quota: coke (84 feem pua) 510kg/t, sulfuric acid (100 feem pua) 950kg/t, caustic soda (100 feem pua) 920kg/t.
3. Nyob rau hauv qhov xwm txheej, oxalic acid feem ntau muaj nyob rau hauv ntau cov nroj tsuag cell membranes nyob rau hauv daim ntawv ntawm ntsev. Yav dhau los, ntoo chips thiab muaj zog alkali tau siv los ua ke ntawm 240 ~ 250 degree hauv kev lag luam ua ntej tsim oxalate, thiab tom qab ntawd acidified kom tau oxalic acid. Tom qab ntawd, oxalic acid tau tsim los ntawm dehydrogenation ntawm sodium formate. Hauv kev lag luam, carbon monoxide (xws li cov pa roj carbon monoxide los ntawm daj phosphorus ntau lawm) yog absorbed los ntawm caustic soda los tsim sodium formate, uas yog dehydrogenated ntawm 380 degree kom tau sodium oxalate, thiab ces kho nrog txiv qaub thiab sulfuric acid los tsim oxalic acid.