Maleic acid tau pom thawj zaug yuav luag 200 xyoo dhau los. Nws yog synthesized los ntawm distillation ntawm malic acid. Nyob rau hauv lub neej yav tom ntej, nws pom nws daim ntawv thov nyob rau hauv cov tshuaj, thiab qhov no yog tsim nyog tham txog nyob rau hauv kom meej. Txawm li cas los xij, ua ntej peb yuav tham txog nws cov khoom thiab lwm yam nta.
Cov yam ntxwv dav dav
Cov mis rau txiv neej acid zoo li no: HOOC-CH=CH-COOH (los yog H4C4O 4 ). Cov tshuaj no yog cov organic compound nrog ob lub hauv paus. Raws li IUPAC nomenclature, nws raug hu ua cis-butenedioic acid.
Cov yam ntxwv ntawm cov tshuaj no tuaj yeem txheeb xyuas hauv cov npe hauv qab no:
Cov molar loj yog 116.07 g / mol.
Ceev yog 1.59 g / cm³.
· Lub melting thiab decomposition kub mus txog 135 ° C. Flash tshwm sim ntawm 127 ° C.
· Dej solubility Performance index yog 78.8 g / l. Cov txheej txheem no ua haujlwm zoo tshaj plaws ntawm 25 ° C.
Cov tshuaj no muaj trans isomer, thiab nwshu ua fumaric acid. Nws cov molecules ruaj khov dua li cov txiv neej. Li no qhov sib txawv ntawm combustion kub, uas yog 22.7 kJ / mol.
Thiab fumaric acid, tsis zoo li txiv neej acid, yog qhov tsis zoo hauv dej. Tsuas yog 6.3 g / l. Qhov no yog vim lub fact tias ib tug hydrogen daim ntawv cog lus yog tsim nyob rau hauv maleic molecules.
Ntaus khoom
Maleic acid yog tsim los ntawm hydrolysis ntawm anhydride C4H2O3. Nws yog ib qho organic compound uas muaj cov khoom sib xws hauv nws lub xeev ntshiab. Cov khoom no feem ntau tsis muaj xim lossis dawb.
Anhydride muaj ntau yam tshuaj lom neeg, vim tias nws muaj qhov ua haujlwm siab heev thiab ob pawg ua haujlwm. Maleic acid yog tsim los ntawm nws cov kev cuam tshuam nrog dej. Tab sis yog tias koj muab nws nrog cawv, koj tau txais cov esters tsis tiav.
Cov anhydride nws tus kheej yog yav tas los ua ke los ntawm oxidation ntawm benzene los yog lwm yam tshuaj tsw qab. Tam sim no txoj kev no tsis tshua siv. Vim qhov nce ntawm cov nqi rau benzene thiab qhov cuam tshuam ntawm cov khoom no rau ib puag ncig, nws tau hloov los ntawm n-butane, hydrocarbon ntawm chav kawm alkane.
Nkag mus rau hauv cov tshuaj tiv thaiv
Nws tsim nyog sau cia tias cov tshuaj txiv neej tuaj yeem hloov mus ua malic acid. Qhov no yog ua tiav los ntawm hydration - qhov sib ntxiv ntawm cov dej molecules rau ions / particles ntawm cov khoom tseem ceeb. Malic acid yog lub npe hu ua cov khoom noj khoom haus ntxiv raws li E296. Nws muaj ib tug natural keeb kwm, yog li nws yog siv nyob rau hauvconfectionery thiab nyob rau hauv zus tau tej cov txiv hmab txiv ntoo dej. Nws kuj tseem siv tau hauv tshuaj.
Tsis tas li ntawd, cov txiv hmab txiv ntoo tuaj yeem hloov mus rau succinic acid, uas yog siv los txhawb cov nroj tsuag kev loj hlob thiab nce yields. Nws yog thawj zaug tau txais nyob rau hauv lub xyoo pua 17th los ntawm distillation ntawm amber. Thiab tam sim no cov tshuaj no yog synthesized los ntawm hydrogenation ntawm maleic acid. Ntawd yog, los ntawm kev ntxiv hydrogen rau nws. Thiab los ntawm lub cev qhuav dej (cleavage ntawm dej los ntawm molecules), txiv neej anhydride tuaj yeem tau los ntawm nws.
Txhua qhov kev tshuaj xyuas tau teev tseg tuaj yeem siv tau hauv kev lag luam rau kev tsim cov tshuaj no. Tab sis lawv tsis muaj kev lag luam, yog li lawv tsis siv rau.
Daim ntawv thov
Nws nyuaj rau overestimate cov khoom ntawm maleic acid. Nws tus kheej tsuas yog siv kom tau txais ib qho fumaric compound, tab sis kev siv nws cov derivatives yog dav:
· Cov anhydride yog siv los tsim cov khoom polyester. Me me, tshwj xeeb. Cov khoom kawg yog nquag siv hauv kev tsim kho kev lag luam. Cov no yog cov khoom siv pleev xim, pob zeb dag, fiberglass, thiab lwm yam.
· Reagents yog siv los ua alkyd resins, uas yog cov hardeners zoo heev rau roj-raws li txheej. Lawv kuj tau siv los ua cov tshuaj tiv thaiv corrosion.
Anhydride kuj tseem siv los ua copolymer ntawm cov txiv neej acid los ua cov ntaub hluavtaws thiab cov khoom siv dag zog.
· Ethers ntawm cov tshuaj no yog siv los ua cov kuab tshuaj. Feem ntau yog diethyl maleate. Nwssiv los ntawm chemistry labs, kev lag luam tiv thaiv, thiab kev lag luam xim thiab kua roj vanish.
· Cov txiv neej compound hydrazite yog siv los ua tshuaj ntsuab. Nws yog ib qho zoo heev ntawm kev tua cov nroj tsuag.
YKev tsim cov fumaric acid
Nws tseem yuav tau hais ob peb lo lus hais txog nws. Yuav kom tau txais fumaric acid, maleic acid yog catalytically isomerized. Cov txheej txheem no yog ua los ntawm kev siv thiourea (thiocarbamide). Txawm hais tias nws feem ntau hloov nrog inorganic acids.
Txij li cov fumaric compound tsis zoo soluble, nws yooj yim rau cais nws los ntawm cov txiv neej. Ob qho acids yog conformers - lawv muaj tib tus lej ntawm atoms thiab molecules, nrog rau cov qauv zoo sib xws. Txawm li cas los xij, txawm li cas los xij, lawv tsis tuaj yeem tig mus rau ib leeg. Rau cov txheej txheem no tshwm sim, nws yog ib qho tsim nyog los rhuav tshem cov pa roj carbon ob daim ntawv cog lus, tab sis qhov no tsis zoo los ntawm lub zog ntawm qhov pom.
Yog li kev lag luam siv txoj kev uas twb tau hais ua ntej lawm - catalytic isomerization ntawm cov txiv neej compound hauv dej.
Siv fumaric compound
Qhov no tsim nyog hais txog thaum kawg. Kev siv ntev tshaj plaws ntawm fumaric acid yog nyob rau hauv kev lag luam zaub mov. Nws yog thawj zaug siv nyob rau hauv 1946. Cov tshuaj no muaj ib tug fruity saj, uas yog vim li cas nws yog feem ntau siv raws li ib tug sweetener. Tsim E297.
Fumaric acid kuj feem ntau hloov nrog tartaric thiab citric acid. Nws raug nqi zoo. Yog tias koj ntxiv citrate, ces kom ua tiav qhov xav tau1.36 g ntawm fumarate yog xav tau rau cov nyhuv saj, tsawg fumarate yog xav tau - tsuas yog 0.91 g.
Ethers ntawm cov tshuaj no kuj tseem siv los kho cov kab mob ntawm daim tawv nqaij xws li psoriasis. Rau ib tug neeg laus, qhov kev cai niaj hnub yog 60-105 milligrams (qhov koob meej nyob ntawm tus neeg mob). Tej zaum yuav nce ntxiv mus rau 1300 mg txhua hnub.
Thiab ntsev ntawm cov tshuaj no yog ib qho tseem ceeb ntawm cov tshuaj xws li Konfumin thiab Mafusol. Thawj pab lub cev hloov mus rau qhov tsis muaj oxygen thiab tswj cov metabolism. Thiab qhov thib ob txhim kho cov khoom rheological ntawm cov ntshav thiab nws cov viscosity.
Ntxim qab kawg, txawm tias tib neeg lub cev muaj peev xwm ua kom cov fumarate. Nws yog tsim los ntawm daim tawv nqaij thaum nws raug tshav ntuj. Tsis tas li ntawd, fumarate yog ib yam khoom los ntawm lub voj voog urea.
