Polyols: characterization, kev npaj thiab kev siv ntawm

Alcohols yog muab hydrocarbon molecules nyob rau hauv uas ib tug los yog ntau tshaj hydrogen atoms nyob ze rau lub uas cov pa roj carbon atom yog pawg nrog ib tug hydroxy pab pawg neeg - OH. Nws yog experimentally muaj pov thawj hais tias tus nqi ntawm cov cawv hydroxyls nyob rau hauv lub molecule yuav tsis pub tshaj tus xov tooj ntawm hydrocarbon atoms. Nyob ntawm seb qhov xwm ntawm tus radical, paub qhov txawv acyclic (aliphatic) thiab cyclic alcohols; los ntawm tus xov tooj ntawm hydroxyl pawg, - mono-, di-, peb thiab polyhydric alcohols; saturation - nyeem thiab unsaturated; qhov chaw localization ntawm ib tug hydroxyl pab pawg neeg nyob rau hauv ib tug hydrocarbon saw - cov thawj, nrab thiab tertiary alcohols.

Polyhydric alcohols - derivatives ntawm alkanes nyob rau hauv molecules uas muaj ntau tshaj peb hydrogen atoms yog hloov los ntawm hydroxy - OH. Rau cov polyhydric alcohols li cov derivatives ntawm monosaccharides yus isomerism thiab kho qhov muag isomerism txoj hauj lwm nyob rau hauv lub hydrocarbon saw OH pab pawg neeg. Kho qhov muag isomerism koom lub peev xwm ntawm tej pab pawg ntawm cov organic tshuaj nyob rau hauv lub ntsiab muaj kho qhov muag ua si. Kho qhov muag ua si ntawm tshuaj yog txiav txim siv ib tug polarimeter.

Zoo tshuaj tiv thaiv nyob rau hauv polyols

Feem ntau cov tshuaj tiv thaiv rau qhov zoo polyols yog lawv sis raug zoo nrog tooj liab hydroxide. Thaum lub sij hawm cov tshuaj tiv thaiv hydroxide dissolves, li no txoj kev ua ib chelate complex ntshav.

Polyols: lub ntsiab cov neeg sawv cev

S4N6 Chetyrehatomnye alcohols (OH) 4 hu ua tetritami, pentahydric S5N7 (OH) 5 - pentitami, hexahydric alcohols S6N8 (OH) 6 - hexitols. Nyob rau hauv txhua xws pab pawg neeg txawv neeg alcohols uas muaj keeb kwm npe: erythritol, arabitol, sorbitol, xylitol, dulcitol, mannitol, etc.

Kev npaj polyalcohols

Cov alcohols yog tsim los ntawm yuav txo tau ntawm monosaccharides, lub hws ntawm aldehydes nrog formaldehyde nyob rau hauv ib tug alkaline medium. Heev feem ntau, polyhydric alcohols npaj los ntawm tej yam ntuj tso raw cov ntaub ntawv. Ib txhia alcohols rho tawm los ntawm lub roob tshauv txiv hmab txiv ntoo.

Polyhydric alcohols - optically active compound, heev soluble nyob rau hauv cov dej. Lub IR thiab UV spectra muaj haum bands raug OH pawg ntawm monohydric alcohols. Tshuaj thaj chaw ntawm alcohols vim lub xub ntiag ntawm OH pawg. Nyob rau hauv cov tshuaj tiv thaiv ntawm cov tebchaw nrog alkaline ntiaj teb co tsim alcoholates - saccharate. Nyob rau hauv lub oxidation ntawm hydroxyl uas yog laus nyob ze ntawm lub thawj carbon atom (C1) yog tsim monosaccharides.

Polyols: lub ntsiab cov neeg sawv cev

Erythritol HOCH 2 (CHOH) 2SN2ON - crystalline tshuaj melts ntawm 121,5 ° C. Qhov saum toj no haus dej haus cawv muaj nyob rau hauv Lichens thiab mosses. Erythritol yuav tau vim cov rov qab los ntawm 1,3-butadiene thiab erythrose. Hais tias dej caw yog siv nyob rau hauv qhov siv thiab ua heev tebchaw, ceev-kom qhuav inks, emulsifiers.

Xylitol HOCH 2 (CHOH) 3SNON - qab zib muaju, nkag soluble nyob rau hauv dej, melted ntawm ib tug kub ntawm 61,5 degrees. Qhov saum toj no haus dej haus cawv yuav tsim los ntawm yuav txo tau ntawm xylose. Xylitol siv nyob rau hauv cov zaub mov kev lag luam nyob rau hauv qhov siv thiab ua cov khoom noj rau diabetics, raws li zoo raws li nyob rau hauv qhov siv thiab ua alkyd resins, kom qhuav roj, thiab surfactants.

Pentaerythritol, C (CH2OH) 4 - khoom tsis zoo soluble nyob rau hauv cov dej. Tau los ntawm reacting formaldehyde nrog acetaldehyde nyob rau hauv lub xub ntiag ntawm Ca (OH) 2. Nws yog siv nyob rau hauv qhov siv thiab ua polyesters, alkyd resins, tetrapentaeritrita, surfactants, plasticizers rau polyvinyl tshuaj dawb, hluavtaws roj. Qhia narcotic zog.

Mannitol HOCH 2 (CHOH) 4SN2ON - Sweet saj tshuaj melts ntawm 165 degrees. Muaj nyob rau hauv mosses, fungi, algae, siab dua nroj tsuag. Hos raws li ib tug diuretic thiab raws li ib tug muaj ntawm kom hniav zoo nkauj khoom (tshuaj pleev).

D-sorbitol HOCH 2 (CHOH) 4SN2ON - melts ntawm 96 degrees. Lub cawv nplua nuj txiv hmab txiv ntoo ntawm roob tshauv. Sorbitol yog tau nyob rau hauv lub yuav txo tau ntawm qabzib. Hais tias dej caw yog ib nrab cov khoom nyob rau hauv lub synthesis ntawm vitamin C, qhia tau hais tias diuretic txiav txim, siv raws li ib tug kev hloov rau sucrose diabetics.