Hydroxypropyl Methyl Cellulose Ether Technology

Hydroxypropyl methyl cellulose ether waa nooc ka mid ah ether cellulose nonpolar oo ku milmay biyo qabow oo laga helay cellulose dabiiciga ah iyada oo loo marayo alkalization iyo hagaajinta etherification.

Erayada Furahahydroxypropyl methylcellulose ether; falcelinta alkalization; falcelinta etherification

1. Farsamada

Cellulose dabiiciga ah waa mid aan lagu milmin biyaha iyo dareerayaasha organic, waxay deggan yihiin iftiinka, kulaylka, acid, milixda iyo warbaahinta kale ee kiimikaad, waxaana lagu qoyn karaa xalalka alkali ee milan si loo beddelo dusha sare ee cellulose.

Hydroxypropyl methyl cellulose ether waa nooc ka mid ah non-polar, eter cellulose biyo-qabow-milmi kara oo laga helay cellulose dabiiciga ah iyada oo loo marayo alkalization iyo etherification wax ka beddelka.

2. Qaabka falcelinta kiimikada ee ugu weyn

2.1 falcelinta Alkalisation

Waxaa jira laba fursadood oo loogu talagalay falcelinta cellulose iyo sodium hydroxide, taas oo ah, marka loo eego xaalado kala duwan si loo abuuro xeryahooda molecular, R - OH - NaOH; ama in la sameeyo isku-dhisyada aalkolada ee birta ah, R - ONa.

Culimada badankoodu waxay aaminsan yihiin in cellulose ay la falgasho alkali xoog leh si ay u sameeyaan walax go'an, waxayna u maleynayaan in mid kasta ama laba kooxood oo gulukoos ah lagu daray hal NaOH molecule (hal koox gulukoos ah ayaa lagu daraa saddex molecules NaOH marka falcelintu dhammaato).

C6H10O5 + NaOH→C6H10O5 NaOH ama C6H10O5 + NaOH→C6H10O4 ONa + H2O

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

Dhawaan, aqoonyahannada qaarkood waxay aaminsan yihiin in isdhexgalka ka dhexeeya cellulose iyo alkali xoogga leh ay yeelan doonaan laba saameyn isku mar.

Iyadoo aan loo eegin qaab-dhismeedka, dhaqdhaqaaqa kiimikada ee cellulose waa la bedeli karaa ka dib falgalka cellulose iyo alkali, waxayna ka falcelin kartaa warbaahinta kiimikada ee kala duwan si loo helo noocyo macno leh.

2.2 Falcelinta Etherification

Alkalization ka dib, cellulose alkali firfircoon ka falcelisa wakiilka etherification si ay u sameeyaan ether cellulose. Walxaha etherifying la isticmaalo waa methyl chloride iyo propylene oxide.

Sodium hydroxide wuxuu u dhaqmaa sida kicinta.

n iyo m waxay matalaan heerka beddelka hydroxypropyl iyo methyl ee unugga cellulose, siday u kala horreeyaan. Wadarta ugu badan ee m + n waa 3.

Marka laga soo tago falcelinta muhiimka ah ee aan kor ku soo sheegnay, waxa kale oo jira falcelino dhinac ah:

CH2CH2OCH3 + H2O→HOCH2CH2OHCH3

CH3Cl + NaOH→CH3OH + NaCl

3. Sharaxaada habsocodka ee ether-ka hydroxypropyl methylcellulose

Habka hydroxypropyl methyl cellulose ether ("cellulose ether") ayaa qiyaas ahaan ka kooban hababka 6, kuwaas oo ah: burburinta alaabta ceeriin, (alkalinization) etherification, saarista dareeraha, sifeynta iyo qalajinta, burburinta iyo isku dhafka, iyo baakadaha alaabta la dhammeeyey.

3.1 Diyaarinta alaabta ceeriin

Cellulose-ga-gaaban ee dabiiciga ah ee laga iibsado suuqa waxaa lagu jajabiyaa budo by pulverizer si loo fududeeyo habka xiga; alkali adag (ama alkali dareere ah) waa la dhalaalay oo la diyaariyey, oo la kululeeyaa ilaa 90°C in la sameeyo 50 % soodhaha soodhaha si loo isticmaalo. Diyaari falcelinta methyl chloride, wakiilka etherification propylene oxide, isopropanol iyo dareeraha falcelinta toluene isku mar.

Intaa waxaa dheer, habka falcelintu wuxuu u baahan yahay qalab caawiye ah sida biyo kulul iyo biyo saafi ah; uumi, biyo qaboojin heer-ku-yar, iyo biyaha qaboojinta wareega ayaa loo baahan yahay si ay u caawiyaan korontada.

Litters gaaban, chloride methyl, iyo propylene oxide etherification wakiilada ayaa ah alaabta ugu muhiimsan ee soo saarida cellulose etherified, iyo linters gaaban ayaa loo isticmaalaa qadar badan. Methyl chloride iyo propylene oxide waxay ka qaybqaataan falcelinta sida wakiilada etherification si ay wax uga beddelaan cellulose dabiiciga ah, qadarka isticmaalka ma badna.

Xalalka (ama dareeraha) inta badan waxaa ka mid ah toluene iyo isopropanol, kuwaas oo asal ahaan aan la isticmaalin, laakiin marka la eego khasaaraha la isku dhejiyay iyo kuwa aan isbeddelin, waxaa jira khasaare yar oo wax soo saar ah, qadarka la isticmaalo waa mid aad u yar.

Habka diyaarinta alaabta ceeriin waxa uu leeyahay meel haanta alaabta ceeriin iyo bakhaar alaabta ceeriin ku lifaaqan. Walxaha qallajiya iyo dareerayaasha, sida toluene, isopropanol, iyo acetic acid (loo isticmaalo in lagu hagaajiyo qiimaha pH ee reactants), ayaa lagu kaydiyaa aagga taangiga alaabta ceeriin. Sahayda lint gaaban ayaa ku filan, waxaa bixin kara suuqa wakhti kasta.

Laydhka gaaban ee la jajabiyey ayaa loo soo diraa aqoon-is-weydaarsiga isagoo wata gaari si loo isticmaalo.

3.2 (Alkalinization) etherification

(Alkaline) etherification waa geeddi-socod muhiim ah oo ku jira habka etherification ee cellulose. Habka wax soo saarka hore, falcelinta laba-tallaabo ayaa si gaar ah loo fuliyay. Hadda geeddi-socodku waa la hagaajiyay, falcelinta laba-tallaabo ayaa la isku daraa hal mar oo isku mar ah.

Marka hore, faakiymee taangiga etherification si aad hawada uga saarto, ka dibna ku beddel nitrogen si taangiga uga dhigo mid ka xor ah hawo. Ku dar xalinta sodium hydroxide ee diyaarsan, ku dar qadar go'an oo isopropanol ah iyo dareeraha toluene, billow walaaq, ka dibna ku dar dhogorta suufka gaaban, shid biyaha wareega si aad u qaboojiso, ka dib marka heerkulku hoos u dhaco heer gaar ah, shid kuwa hooseeya- heerkulka biyaha si loo yareeyo heerkulka walxaha nidaamka Hoos u dhig ilaa 20℃, oo sii wad falcelinta ilaa wakhti go'an si aad u dhamaystirto alkalization.

Alkalization ka dib, ku dar wakiilka etherifying methyl chloride iyo propylene oxide lagu qiyaaso haanta cabbirada heerka sare, sii wad si aad u bilowdo walaaq, isticmaal uumiga si kor loogu qaado heerkulka nidaamka ilaa 70 ku dhawaad.℃~ 80℃, ka dibna isticmaal biyo kulul si aad u sii wado kuleylka iyo ilaalinta Heerkulka falcelinta ayaa la xakameynayaa, ka dibna heerkulka falcelinta iyo waqtiga falcelinta ayaa la xakameynayaa, waxaana qalliinka lagu dhameyn karaa walaaq iyo isku dhafka wakhti go'an.

Falcelinta waxaa la sameeyaa qiyaastii 90°C iyo 0.3 MPa.

3.3 Burburinta

Qalabka habraaca ee kor ku xusan ee la falceliyay waxaa loo diraa alwaaxiyaha, alaabtana waa la siibinayaa oo lagu kululeeyaa uumi, iyo dareerayaasha toluene iyo isopropanol waa la uumi baxa oo dib loo warshadeeyaa.

Walxaha uumi baxay ayaa marka hore la qaboojiyaa oo qayb ahaan lagu ururiyaa biyo wareeg ah, ka dibna lagu ururiyo biyo heerkulka hooseeya, isku dar ah kondensate wuxuu galayaa lakabka dareeraha ah iyo kala-soocida si loo kala saaro biyaha iyo dareeraha. Walxaha isku dhafan ee toluene iyo isopropanol ee lakabka sare ayaa lagu hagaajiyaa qiyaasta. Si toos ah u isticmaal, oo ku soo celi biyaha iyo xalalka isopropanol ee lakabka hoose ee dareeraha si loo isticmaalo.

Ku dar acetic acid fal-celiyeyaasha ka dib marka ay dhalaaliso si ay u baabi'iso sodium hydroxide xad-dhaaf ah, ka dibna isticmaal biyo kulul si aad u dhaqdo walxaha, si buuxda u isticmaal sifada xinjirowga ee etherka cellulose biyaha kulul si aad u dhaqdo etherka cellulose, oo sifeyso fal-celinta. Qalabka la sifeeyay ayaa loo diraa habka soo socda si loo kala saaro loona qalajiyo.

3.4 Sifee oo qalaji

Walaxda la safeeyey waxaa loo diraa kala-soocida furaha jiifka ah iyada oo loo marayo bamka cadaadiska sare si loo kala saaro biyaha bilaashka ah, walxaha adag ee soo hadhayna waxay gelayaan qalajiyaha hawada iyada oo loo marayo feederiyaha, oo la qalajiyo iyada oo la taabto hawo kulul, ka dibna waxay sii maraan duufaanta. kala-soocidda iyo hawada Kala-soocidda, walxaha adag waxay galaan burburinta xigta.

Biyaha ay kala soocaan kala-soocida wareega ee jiifka ah waxay galaan taangiga daaweynta biyaha ka dib markii ay ku sii daayaan taangiga sedimentation si ay u kala soocaan cellulose-ka la galiyay.

3.5 Burburinta iyo isku dhafka

Ka dib marka la qalajiyo, cellulose etherified waxay yeelan doontaa cabbirka walxaha aan sinnayn, kaas oo u baahan in la jajabiyo oo la isku daro si qaybinta cabbirka qaybinta iyo muuqaalka guud ee maaddadu ay u buuxiso shuruudaha heerka sheyga.

3. 6 Baakadaha alaabta la dhammeeyay

Walxaha la helay ka dib markii la burburiyo iyo hawlgallada isku dhafka ah waa cellulose etherified la dhammeeyey, kaas oo la baakadeeyey oo la gelin karo kaydinta.

4. Kooban

Biyaha wasakhda ah ee kala soocan waxay ka kooban yihiin xaddi milix ah, oo ay ugu badan tahay sodium chloride. Biyaha wasakhda ah waa la soo daadiyaa si loo kala saaro milixda, iyo uumiga labaad ee uumi-baxay waa la isku ururin karaa si uu u soo kabsado biyaha cufan, ama si toos ah loo sii daayo. Qaybta ugu muhiimsan ee cusbada kala go'an waa sodium chloride, taas oo sidoo kale ku jirta qadar go'an oo sodium acetate ah sababtoo ah dhexdhexaadinta acetic acid. Cusbadani waxay leedahay qiimaha ka faa'iidaysiga warshadaha kaliya ka dib dib-u-cystallization, kala-soocid iyo nadiifin.