Hydroxypropyl Methyl Cellulose Etere Technology

Hydroxypropyl methyl cellulose ether ndi mtundu wa nonpolar cellulose ether sungunuka m'madzi ozizira otengedwa kuchokera ku cellulose yachilengedwe kudzera mu alkalization ndi etherification kusinthidwa.

Mawu osakira:hydroxypropyl methylcellulose ether; alkalization anachita; etherification reaction

1. Zamakono

Natural mapadi ndi insoluble m'madzi ndi zosungunulira organic, khola kuwala, kutentha, asidi, mchere ndi zina mankhwala TV, ndipo akhoza wothira mu kuchepetsa alkali njira kusintha padziko mapadi.

Hydroxypropyl methyl cellulose ether ndi mtundu wa ether wopanda polar, wosungunuka m'madzi ozizira wosungunuka kuchokera ku cellulose wachilengedwe kudzera mu alkalization ndi etherification kusinthidwa.

2. Waukulu mankhwala anachita chilinganizo

2.1 Kuchita kwa alkalization

Pali njira ziwiri zomwe zimachitika pa cellulose ndi sodium hydroxide, ndiye kuti, malinga ndi zinthu zosiyanasiyana kuti apange mankhwala opangidwa ndi maselo, R - OH - NaOH; kapena kupanga mankhwala achitsulo, R - ONa.

Akatswiri ambiri amakhulupirira kuti cellulose imagwira ntchito ndi alkali wokhazikika kuti apange chinthu chokhazikika, ndikuganiza kuti gulu lililonse kapena awiri a shuga amaphatikizidwa ndi molekyu imodzi ya NaOH (gulu limodzi la shuga limaphatikizidwa ndi mamolekyu atatu a NaOH pamene zochita zatha).

C6H10O5 + NaOH→C6H10O5 NaOH kapena C6H10O5 + NaOH→C6H10O4 ONa + H2O

C6H10O5 + NaOH→(C6H10O5 ) 2 NaOH kapena C6H10O5 + NaOH→C6H10O5 C6H10O4 ONa + H2O

Posachedwapa, akatswiri ena amakhulupirira kuti kugwirizana pakati pa cellulose ndi ndende ya alkali kudzakhala ndi zotsatira ziwiri panthawi imodzi.

Mosasamala kanthu za kapangidwe kake, ntchito yamankhwala a cellulose imatha kusinthidwa pambuyo pakuchita kwa cellulose ndi alkali, ndipo imatha kuchitapo kanthu ndi mitundu yosiyanasiyana yamankhwala kuti ipeze mitundu yothandiza.

2.2 Etherification reaction

Pambuyo pa alkalization, cellulose yogwira ntchito ya alkali imakumana ndi etherification wothandizila kupanga cellulose ether. Ma etherifying agents omwe amagwiritsidwa ntchito ndi methyl chloride ndi propylene oxide.

Sodium hydroxide imagwira ntchito ngati chothandizira.

n ndi m imayimira kuchuluka kwa kusintha kwa hydroxypropyl ndi methyl pa cellulose unit, motsatana. Chiwerengero chachikulu cha m + n ndi 3.

Kuphatikiza pa zomwe tazitchula pamwambazi, palinso kuyabwa:

CH2CH2OCH3 + H2O→HOCH2CH2OHCH3

CH3Cl + NaOH→CH3OH + NaCl

3. Kufotokozera kwa ndondomeko ya hydroxypropyl methylcellulose ether

Njira ya hydroxypropyl methyl cellulose ether ("cellulose ether" mwachidule) imapangidwa ndi njira 6, zomwe ndi: kuphwanya zopangira, (alkalinization) etherification, kuchotsa zosungunulira, kusefera ndi kuyanika, kuphwanya ndi kusakaniza, ndikumaliza kuyika mankhwala.

3.1 Kukonzekera zakuthupi

Ma cellulose achilengedwe atali-lint omwe amagulidwa pamsika amaphwanyidwa kukhala ufa ndi pulverizer kuti athandizire kukonza kotsatira; alkali wolimba (kapena alkali wamadzimadzi) amasungunuka ndikukonzedwa, ndikutenthedwa mpaka pafupifupi 90°C kupanga 50% caustic soda solution kuti mugwiritse ntchito. Konzani zochita za methyl chloride, propylene oxide etherification agent, isopropanol ndi toluene reaction solvent pa nthawi yomweyo.

Kuphatikiza apo, zomwe zimachitika zimafunikira zida zothandizira monga madzi otentha ndi madzi oyera; nthunzi, madzi ozizira ozizira otsika, ndi madzi ozizira ozungulira amafunikira kuthandiza mphamvu.

Ma linter amfupi, methyl chloride, ndi propylene oxide etherification agents ndizo zida zazikulu zopangira cellulose ya etherified, ndipo malita amfupi amagwiritsidwa ntchito mochuluka. Methyl chloride ndi propylene oxide amatenga nawo gawo pochita monga etherification agents kuti asinthe cellulose yachilengedwe, kuchuluka kwa kugwiritsidwa ntchito si kwakukulu.

Zosungunulira (kapena zosungunulira) makamaka zimaphatikizapo toluene ndi isopropanol, zomwe sizimadyedwa, koma poyang'ana zowonongeka ndi zowonongeka, pali kutaya pang'ono pakupanga, ndipo ndalama zomwe zimagwiritsidwa ntchito ndizochepa kwambiri.

Njira yokonzekera zopangira ili ndi malo osungiramo zinthu zopangira komanso malo osungiramo zinthu. Etherifying agents ndi solvents, monga toluene, isopropanol, ndi acetic acid (omwe amagwiritsidwa ntchito kuti asinthe pH mtengo wa reactants), amasungidwa m'dera la tanki yaiwisi. Kupereka kwa lint lalifupi ndikokwanira , kungaperekedwe ndi msika nthawi iliyonse.

Lint lalifupi lophwanyidwa limatumizidwa ku msonkhano ndi ngolo kuti mugwiritse ntchito.

3.2 (Alkalinization) etherification

(Zamchere) etherification ndi njira yofunika kwambiri pakupanga etherification wa cellulose. Mu njira yoyamba yopangira, machitidwe awiriwa adachitidwa mosiyana. Tsopano ndondomekoyi imapangidwa bwino, ndipo zochitika ziwirizi zimaphatikizidwa mu gawo limodzi ndikuchitika nthawi imodzi.

Choyamba, yeretsani thanki ya etherification kuti muchotse mpweya, kenaka m'malo mwake ndi nayitrogeni kuti tanki ikhale yopanda mpweya. Onjezani okonzeka sodium hydroxide njira, kuwonjezera ena kuchuluka kwa isopropanol ndi toluene zosungunulira, kuyamba kuyambitsa, ndiye kuwonjezera yochepa thonje ubweya, kuyatsa madzi ozungulira kuziziritsa, ndipo pambuyo kutentha akutsikira kwa mlingo winawake, kuyatsa otsika-. kutentha kwa madzi kuti muchepetse kutentha kwa dongosolo Kutsika mpaka pafupifupi 20℃, ndi kusunga zomwe anachita kwa nthawi inayake kuti amalize alkalization.

Pambuyo alkalization, kuwonjezera etherifying wothandizila methyl kolorayidi ndi propylene okusayidi kuyeza ndi mkulu mlingo metering thanki, pitirizani kuyamba kuyambitsa, ntchito nthunzi kukweza dongosolo kutentha kwa pafupifupi 70.℃~80 pa℃, ndiyeno gwiritsani ntchito madzi otentha kuti mupitilize kutentha ndi kusunga Kutentha kwazomwe zimayendetsedwa, ndiyeno kutentha komwe kumayendetsedwa ndi nthawi yochitira kumayendetsedwa, ndipo ntchitoyo ikhoza kutha poyambitsa ndi kusakaniza kwa nthawi inayake.

Zomwe zimachitika zimachitika pafupifupi 90°C ndi 0.3 MPa.

3.3 Kuwonongeka

Zomwe tazitchula pamwambapa zimatumizidwa ku desolventizer, ndipo zidazo zimachotsedwa ndikutenthedwa ndi nthunzi, ndipo toluene ndi isopropanol zosungunulira zimatuluka nthunzi ndikubwezeretsedwanso kuti zibwezeretsenso.

The zosungunulira chamunthuyo choyamba utakhazikika ndi pang'ono condensed ndi kufalitsidwa madzi, ndiyeno condensed ndi otsika kutentha madzi, ndi condensate osakaniza amalowa madzi wosanjikiza ndi olekanitsa kulekanitsa madzi ndi zosungunulira. Zosungunulira zosakanikirana za toluene ndi isopropanol kumtunda wosanjikiza zimasinthidwa molingana. Gwiritsani ntchito mwachindunji, ndikubwezerani madzi ndi isopropanol yankho m'munsi mwa desolventizer kuti mugwiritse ntchito.

Onjezani asidi acetic kwa reactant pambuyo desolnation kuti neutralize owonjezera sodium hydroxide, ndiye ntchito madzi otentha kutsuka zakuthupi, ntchito mokwanira coagulation khalidwe la mapadi efa madzi otentha kutsuka mapadi efa, ndi yeretsani reactant. Zida zoyengedwa zimatumizidwa ku njira yotsatira yolekanitsa ndi kuyanika.

3.4 Sefa ndi kuumitsa

Zinthu zoyengedwa zimatumizidwa ku cholekanitsa chopingasa chopingasa ndi pampu yothamanga kwambiri kuti ilekanitse madzi aulere, ndipo zotsalira zolimba zimalowa mu chowumitsira mpweya kudzera pa wononga wononga, ndikuwumitsa pokhudzana ndi mpweya wotentha, kenako ndikudutsa mkuntho. olekanitsa ndi mpweya Kupatukana, zinthu olimba kulowa wotsatira kuphwanya.

Madzi olekanitsidwa ndi chopingasa chopingasa chozungulira amalowa m'thanki yopangira madzi pambuyo pa kusungunuka mu thanki ya sedimentation kuti alekanitse cellulose yomwe ili mkati.

3.5 Kuphwanya ndi kusakaniza

Pambuyo kuyanika, mapadi etherified adzakhala ndi mkangano tinthu kukula, amene ayenera wosweka ndi kusakaniza kuti tinthu kukula kugawa ndi maonekedwe wonse wa zinthu kukumana mankhwala zofunika muyezo.

3. 6 Anamaliza kulongedza katundu

Zomwe zimapezedwa pambuyo pophwanya ndi kusakaniza ntchito ndi cellulose yomalizidwa ya etherified, yomwe imatha kupakidwa ndikusungidwa.

4. Mwachidule

Madzi otayika olekanitsidwa amakhala ndi mchere wambiri, makamaka sodium chloride. Madzi otayidwa amasanduka nthunzi kuti alekanitse mcherewo, ndipo nthunzi yachiwiri yomwe yatuluka imatha kufupikitsidwa kuti ipezenso madzi osungunuka, kapena kutulutsa mwachindunji. Chigawo chachikulu cha mchere wolekanitsidwa ndi sodium kolorayidi, yomwe ilinso ndi sodium acetate chifukwa cha neutralization ndi asidi acetic. Mcherewu uli ndi phindu logwiritsira ntchito mafakitale pokhapokha mutakonzanso, kupatukana ndi kuyeretsedwa.