Yuav ua li cas tshuaj hu ua aldehydes thiab ketones? Kev siv cov aldehydes

Tebchaw muaj nyob rau hauv nws cov qauv ib carbonyl pab pawg neeg yog aldehydes los yog ketones. Lub aldehydes (RCOH) carbonyl pab pawg neeg yog sib raug zoo rau ib tug hydrocarbon radical thiab ib hydrogen atom. Txwv tsis pub, koj muaj peev xwm hais tias cov tshuaj muaj aldehyde pab pawg neeg (-COH), nyob rau hauv uas lub carbonyl center yog kev cob cog rua nrog ib tug hydrogen atom. Lub ketones (RCOR '), ob tug hydrocarbon radicals sib raug zoo rau ib tug carbonyl pab pawg neeg. Lub npe los ntawm cov aldehyde acids, nyob rau hauv uas cov oxidation lawv hloov dua siab tshiab, e.g., ntsaum (formaldehyde), ethyl (acetaldehyde), propionaldehyde, butyric, valeric aldehydes. Raws li thoob ntiaj teb nomenclature hu ua aldehydes: ethanal, propanal. Cov npe ntawm title ketone daim ntawv radicals, uas yog ntxiv xaus ketone. Piv txwv li, dimethyl ketone (acetone), methyl ethyl ketone. Title thoob ntiaj teb nomenclature ketone los ntawm qhov sib ntxiv ntawm hydrocarbon kaw -Ib, thiab tus taw tes ntawm txuas ntawm lub carbonyl pab pawg neeg ntawd hais ib tug xov tooj, piv txwv li 2-propanone, 2-butanone. Siv aldehydes thiab ketones, vim lawv lub cev thiab tshuaj zog.

Aldehydes muaj ntau nyob rau hauv cov organic Science News for KIDS. Muaj ntau fragrances muaj kev cob cog nrog cov tshuaj. Aldehydes muaj zog uas yog varied thiab nyob ntawm seb lub radical constituting lub molecule. Lower Sawv Cev - formic aldehyde - roj, tom ntej - kua, khib nyiab yog ntau dua. Formaldehyde thiab acetaldehyde yog zoo heev soluble nyob rau hauv dej, tus solubility ntawm lwm yam homologs txo nrog ua molecular ceeb thawj. Formic thiab acetic aldehydes muaj ib tug pungent tsw. Zog thiab kev siv cov aldehydes vim lub muaj nyob rau hauv lawv cov molecule ib carbonyl pab pawg neeg.

Ob sab mej zeej ntawm lub homologous series nyob rau hauv lub "siv cov aldehydes" yog cov tseem ceeb tshaj plaws rau kev lag luam tus nqi - yog formaldehyde thiab acetaldehyde. Formaldehyde yog ua rau ib tug loj scale, txog li 6 plhom. Tons / xyoo. Nws yog tsuas yog siv nyob rau hauv qhuav ntawm resins. Npaj los ntawm polycondensation ntawm urea , urea-formaldehyde cob yuav tsum tau rau cov siv thiab ua cov fiber ntau thiab particle boards, urea-formaldehyde ua npuas ncauj, ua ntub dej dag lub zog ntawv los yog paperboard. Ib qho tseem ceeb siv aldehyde raws li nyob rau hauv cov tshuaj tiv thaiv ntawm formaldehyde nrog phenol polycondensation. Cov resultant ntawm tus txheej txheem phenol formaldehyde cob (bakelite) yog unsurpassed khoom, uas yog nyob rau hauv coob nyob rau hauv mechanical engineering, nyob rau hauv qhov siv thiab ua abrasive hluav taws xob khoom, nyob rau hauv qhuav ntawm lacquers thiab adhesives. Npaj los ntawm formaldehyde kws npaj (formaldehyde tshuaj lub npe hu ua formalin, yog siv nyob rau hauv cov tshuaj), hluavtaws roj hmab, explosives thiab ntau lwm yam organic tshuaj.

Acetaldehyde yog ib zaug hauv lub hom khoom, tab sis ntau lawm tagnrho twb down, tam sim no nws ua tsawg tshaj li 1 million. Tuj / xyoo. Yav tas los, siv cov tshuaj acetaldehyde yog li raw cov ntaub ntawv rau acetic acid. Daim ntawv thov no acetaldehyde poob nyob rau hauv xyoo tsis ntev los, vim hais tias acetic acid yog ua ntau nraaj los ntawm methanol (Monsanto txheej txheem thiab Cativa txheej txheem). Los ntawm qhov seem yus pom ntawm lub hws cov tshuaj tiv thaiv, acetaldehyde yog ib qho tseem ceeb raw khoom rau lub pyridine derivatives ntawm pentaerythritol thiab crotonaldehyde. Acetaldehyde xav tau kev pab rau zus tau tej cov yas (pab tau resins npaj los ntawm urea thiab acetaldehyde).

Lwm yam mej zeej ntawm lub homologous series yog tseem nyob rau hauv coob nyob rau hauv kev ua lag luam. Coj mus muag siv aldehydes yog feem ntau lawv yog siv raws li cov ntaub ntawv raw rau lub synthesis ntawm oxo alcohols siv nyob rau hauv qhuav ntawm detergents. Ib txhia siab aldehydes yog ua nyob rau hauv me me qhov ntau (tsawg tshaj li 1000 tons / xyoo) thiab siv raws li ib tug tsw khoom xyaw rau hauv perfumes. Cov no muaj xws cinnamon thiab nws cov derivatives, thiab citral lilial.