Ṣiṣejade awọn ethers cellulose mimọ jẹ awọn igbesẹ pupọ, ti o bẹrẹ lati isediwon ti cellulose lati awọn ohun elo ọgbin si ilana iyipada kemikali.
Sourcing Cellulose: Cellulose, polysaccharide kan ti a rii ninu awọn ogiri sẹẹli ti awọn irugbin, ṣiṣẹ bi ohun elo aise fun awọn ethers cellulose. Awọn orisun ti o wọpọ pẹlu pulp igi, owu, ati awọn ohun ọgbin fibrous miiran bi jute tabi hemp.
Pulping: Pulping jẹ ilana ti yiya sọtọ awọn okun cellulose lati awọn ohun elo ọgbin. Eyi ni deede waye nipasẹ ẹrọ tabi awọn ọna kemikali. pulping ti ẹrọ jẹ lilọ tabi isọdọtun ohun elo lati ya awọn okun kuro, lakoko ti o ti npa kemikali, gẹgẹbi ilana kraft, nlo awọn kemikali bii sodium hydroxide ati sodium sulfide lati tu lignin ati hemicellulose, nlọ cellulose sile.
Bleaching (Aṣayan): Ti o ba fẹ mimọ giga, pulp cellulose le gba ilana bleaching lati yọ eyikeyi lignin ti o ku, hemicellulose, ati awọn aimọ miiran kuro. Chlorine dioxide, hydrogen peroxide, tabi atẹgun jẹ awọn aṣoju bleaching ti o wọpọ ti a lo ni igbesẹ yii.
Muu ṣiṣẹ: Awọn ethers cellulose ni a pese silẹ ni igbagbogbo nipasẹ didaṣe cellulose pẹlu alkali irin hydroxides lati ṣe agbedemeji cellulose alkali. Igbesẹ yii jẹ wiwu awọn okun cellulose ni ojutu ti iṣuu soda hydroxide tabi potasiomu hydroxide ni iwọn otutu ti o ga. Igbesẹ imuṣiṣẹ yii jẹ ki cellulose ni ifaseyin diẹ sii si etherification.
Etherification: Etherification jẹ igbesẹ bọtini ni ṣiṣe awọn ethers cellulose. O kan ṣafihan awọn ẹgbẹ ether (bii methyl, ethyl, hydroxyethyl, tabi awọn ẹgbẹ hydroxypropyl) sori ẹhin cellulose. Ihuwasi yii ni a ṣe ni igbagbogbo nipasẹ ṣiṣe itọju cellulose alkali pẹlu awọn aṣoju atẹri bi alkyl halides (fun apẹẹrẹ, methyl chloride fun methyl cellulose), awọn ohun elo alkylene (fun apẹẹrẹ, ethylene oxide fun hydroxyethyl cellulose), tabi alkyl halohydrins (fun apẹẹrẹ, propylene oxide fun hydroxypropyl cellulose). ) labẹ awọn ipo iṣakoso ti iwọn otutu, titẹ, ati pH.
Neutralization ati Fifọ: Lẹhin ti etherification, awọn lenu adalu ti wa ni didoju lati yọ excess alkali. Eyi ni a maa n ṣe nipa fifi acid kan kun, gẹgẹbi hydrochloric acid tabi sulfuric acid, lati yo alkali kuro ki o si ṣaju ether cellulose. Abajade ọja ti wa ni ki o fo pẹlu omi lati yọ eyikeyi iyokù kemikali ati nipasẹ-ọja.
Gbigbe: Ọja ether cellulose ti a fọ ni igbagbogbo ti gbẹ lati yọ ọrinrin pupọ kuro ati gba iyẹfun ikẹhin tabi fọọmu granular. Eyi le ṣee ṣe nipa lilo awọn ilana bii gbigbe afẹfẹ, gbigbẹ igbale, tabi gbigbẹ fun sokiri.
Iṣakoso Didara: Awọn igbese iṣakoso didara jẹ pataki lati rii daju mimọ, aitasera, ati awọn ohun-ini ti o fẹ ti awọn ethers cellulose. Eyi pẹlu idanwo ọja fun awọn aye bii iwọn aropo, iki, pinpin iwọn patikulu, akoonu ọrinrin, ati mimọ nipa lilo awọn ilana itupalẹ bii titration, viscometry, ati spectroscopy.
Iṣakojọpọ ati Ibi ipamọ: Ni kete ti awọn ethers cellulose ti gbẹ ati idanwo didara, wọn ti ṣajọ sinu awọn apoti ti o dara ati ti a fipamọ sinu awọn ipo iṣakoso lati ṣe idiwọ gbigbe ọrinrin ati ibajẹ. Iforukọsilẹ deede ati iwe awọn alaye ipele tun ṣe pataki fun wiwa kakiri ati ibamu ilana.
Nipa titẹle awọn igbesẹ wọnyi, o ṣee ṣe lati gbe awọn ethers cellulose mimọ pẹlu awọn ohun-ini ti o fẹ fun ọpọlọpọ awọn ohun elo ile-iṣẹ, pẹlu awọn oogun, ounjẹ, awọn ohun ikunra, awọn aṣọ, ati awọn ohun elo ikole.
Akoko ifiweranṣẹ: Oṣu Kẹrin Ọjọ 24-2024