Hydroxypropyl Methyl Cellulose Ether Technology

Hydroxypropyl methyl cellulose ether wani nau'i ne na cellulose ether mai narkewa a cikin ruwan sanyi wanda aka samo daga cellulose na halitta ta hanyar alkalization da gyaran etherification.

Mahimman kalmomi:hydroxypropyl methylcellulose ether; alkalization dauki; etherification dauki

1. Fasaha

Halitta cellulose ne insoluble a cikin ruwa da Organic kaushi, barga zuwa haske, zafi, acid, gishiri da sauran sinadaran kafofin watsa labarai, kuma za a iya moistened a tsarma alkali bayani canza surface na cellulose.

Hydroxypropyl methyl cellulose ether wani nau'i ne na ba iyakacin duniya, ruwan sanyi-mai narkewa cellulose ether samu daga halitta cellulose ta alkalization da etherification gyara.

2. Babban tsarin amsa sinadarai

2.1 Maganin Alkalization

Akwai hanyoyi guda biyu don amsawar cellulose da sodium hydroxide, wato, bisa ga yanayi daban-daban don samar da mahadi na kwayoyin halitta, R - OH - NaOH; ko don samar da mahaɗan barasa na ƙarfe, R - ONa.

Yawancin malamai sun yi imanin cewa cellulose yana amsawa tare da alkali mai mahimmanci don samar da wani abu mai mahimmanci, kuma suna tunanin cewa kowane ko biyu kungiyoyin glucose an haɗa su da kwayoyin NaOH guda ɗaya (ana haɗe rukunin glucose ɗaya tare da kwayoyin NaOH guda uku lokacin da amsawar ta cika).

C6H10O5 + NaOH→C6H10O5 NaOH ko C6H10O5 + NaOH→C6H10O4 ONA + H2O

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

Kwanan nan, wasu masana sun yi imanin cewa hulɗar da ke tsakanin cellulose da alkali mai mahimmanci zai sami tasiri guda biyu a lokaci guda.

Ba tare da la'akari da tsarin ba, ana iya canza aikin sinadarai na cellulose bayan aikin cellulose da alkali, kuma yana iya amsawa tare da kafofin watsa labaru daban-daban don samun nau'i mai ma'ana.

2.2 amsawar etherification

Bayan alkalization, mai aiki alkali cellulose reacts tare da etherification wakili don samar da cellulose ether. Abubuwan etherifying da ake amfani da su sune methyl chloride da propylene oxide.

Sodium hydroxide yana aiki kamar mai kara kuzari.

n da m suna wakiltar matakin maye gurbin hydroxypropyl da methyl akan sashin cellulose, bi da bi. Matsakaicin jimlar m + n shine 3.

Baya ga babban abin da aka ambata a sama, akwai kuma halayen gefe:

CH2CH2OCH3 + H2O→Farashin HOCH2CH2OHCH3

CH3Cl + NaOH→CH3OH + NaCl

3. Bayanin tsari na hydroxypropyl methylcellulose ether

Tsarin hydroxypropyl methyl cellulose ether ("cellulose ether" a takaice) shi ne wajen hada da 6 matakai, wato: albarkatun kasa crushing, (alkalinization) etherification, sauran ƙarfi cire, tacewa da bushewa, murkushe da hadawa, da kuma gama samfurin marufi.

3.1 Shirye-shiryen albarkatun kasa

The halitta short-lint cellulose da aka saya a kasuwa ana murƙushe shi a cikin foda ta hanyar pulverizer don sauƙaƙe aiki na gaba; Ana narke daskararre (ko ruwa alkali) sannan a shirya, sannan a yi zafi zuwa kusan 90°C don yin 50% caustic soda bayani don amfani. Shirya dauki methyl chloride, propylene oxide etherification wakili, isopropanol da toluene sauran ƙarfi dauki lokaci guda.

Bugu da ƙari, tsarin amsawa yana buƙatar kayan taimako kamar ruwan zafi da ruwa mai tsabta; tururi, ruwan sanyi mai ƙarancin zafin jiki, da ruwan sanyi mai kewayawa ana buƙatar don taimakawa wutar lantarki.

Short linters, methyl chloride, da propylene oxide etherification jamiái su ne manyan kayan don samar da etherified cellulose, kuma gajere linters ana amfani da yawa. Methyl chloride da propylene oxide suna shiga cikin amsawa azaman etherification jamiái don gyara cellulose na halitta, adadin amfani ba shi da yawa.

Abubuwan da ake amfani da su (ko diluents) galibi sun haɗa da toluene da isopropanol, waɗanda galibi ba a cinye su ba, amma idan aka yi la’akari da asarar da aka samu da kuma rashin ƙarfi, ana samun ɗan asara a cikin samarwa, kuma adadin da ake amfani da shi kadan ne.

Tsarin shirye-shiryen albarkatun ƙasa yana da yankin tanki mai ɗanɗano da ɗakin ajiyar kayan da aka haɗe. Abubuwan da ke haifar da haɓakawa da kaushi, irin su toluene, isopropanol, da acetic acid (amfani da su don daidaita ƙimar pH na masu amsawa), ana adana su a cikin yankin tanki mai ɗanɗano. Samar da ɗan gajeren lint ya isa, kasuwa za a iya bayarwa a kowane lokaci.

Ana aika gajeriyar lint ɗin da aka murƙushe zuwa wurin bitar tare da keken amfani.

3.2 (Alkalinization) etherification

(Alkali) etherification wani muhimmin tsari ne a cikin tsarin etherification na cellulose. A cikin hanyar samar da baya, an aiwatar da halayen matakai biyu daban. Yanzu an inganta tsarin, kuma ana haɗa halayen matakai biyu a cikin mataki ɗaya kuma ana aiwatar da su lokaci guda.

Da farko, cire tankin da ke da iska don cire iska, sannan a maye gurbin shi da nitrogen don sanya tankin ya zama mara iska. Sai a zuba maganin sodium hydroxide da aka shirya, sai a zuba wani adadin isopropanol da sauran kaushi toluene, sai a fara motsawa, sannan a zuba gajeriyar ulun auduga, kunna ruwan da ke yawo don huce, sannan bayan yanayin zafi ya ragu zuwa wani matakin, kunna low- Ruwan zafin jiki don rage yawan zafin jiki na kayan aiki Sauke zuwa kusan 20℃, da kuma kula da martani na wani ɗan lokaci don kammala alkalization.

Bayan alkalization, ƙara etherifying wakili methyl chloride da propylene oxide auna ta babban matakin metering tanki, ci gaba da fara motsawa, yi amfani da tururi don ɗaga tsarin zafin jiki zuwa kusan 70.℃~ 80℃, sa'an nan kuma amfani da ruwan zafi don ci gaba da dumama da kiyayewa Ana sarrafa yawan zafin jiki, sa'an nan kuma ana sarrafa yawan zafin jiki da lokacin amsawa, kuma ana iya kammala aikin ta hanyar motsawa da haɗuwa na wani lokaci.

Ana aiwatar da martani a kusan 90°C da 0.3 MPa.

3.3 Rushewa

Abubuwan da aka ambata da aka ambata a sama ana aika su zuwa narkar da kayan aikin, kuma ana cire kayan kuma ana dumama su tare da tururi, kuma abubuwan da ake amfani da su na toluene da isopropanol suna ƙafe kuma ana dawo dasu don sake yin amfani da su.

Za a fara sanyaya ƙawancen da aka ƙafe da shi kuma a ɗaure shi da ruwa mai zazzagewa, sa'an nan kuma a sanya shi da ruwa mai zafi, kuma cakudawar condensate ya shiga cikin ruwa mai laushi da mai raba ruwa don raba ruwa da sauran ƙarfi. Haɗaɗɗen kaushi na toluene da isopropanol a cikin babban Layer an daidaita shi daidai gwargwado. Yi amfani da shi kai tsaye, kuma mayar da ruwa da kuma isopropanol bayani a cikin ƙananan Layer zuwa desolventizer don amfani.

Add acetic acid zuwa reactant bayan barewa don kawar da wuce haddi sodium hydroxide, sa'an nan amfani da ruwan zafi don wanke kayan, yin cikakken amfani da coagulation halayyar cellulose ether zuwa ruwan zafi don wanke cellulose ether, da kuma tace reactant. Ana aika kayan da aka gyara zuwa tsari na gaba don rabuwa da bushewa.

3.4 Tace kuma bushe

Ana aika kayan da aka gyara zuwa ga madaidaicin dunƙule ta hanyar famfo mai matsa lamba mai ƙarfi don raba ruwan kyauta, sauran ƙaƙƙarfan abu kuma yana shiga cikin injin busar da iskar ta hanyar injin ɗin, kuma an bushe shi cikin hulɗa da iska mai zafi, sa'an nan kuma ya wuce cikin guguwar. SEPARATOR da iska Rabuwa, da m abu shiga cikin m murkushe.

Ruwan da aka raba ta hanyar karkace mai kwance a kwance yana shiga cikin tanki mai kula da ruwa bayan da aka lalata a cikin tanki mai lalata don raba cellulose mai ciki.

3.5 Murkushewa da hadawa

Bayan bushewa, da etherified cellulose zai sami m barbashi size, wanda bukatar da za a crushed da gauraye sabõda haka, da barbashi size rarraba da kuma overall bayyanar da abu hadu da samfurin misali bukatun.

3. 6 Kammala kayan marufi

Abubuwan da aka samu bayan murkushewa da hadawa ayyukan shine ƙãre etherified cellulose, wanda za a iya kunshe da kuma saka a cikin ajiya.

4. Takaitawa

Ruwan da aka raba ya ƙunshi adadin gishiri, galibi sodium chloride. Ruwan sharar gida yana ƙafewa don raba gishiri, kuma tururi na biyu da ya ƙafe za a iya murƙushe shi don dawo da ruwa mai narkewa, ko kuma a fitar da shi kai tsaye. Babban bangaren gishirin da aka raba shi ne sodium chloride, wanda kuma ya ƙunshi wani adadin sodium acetate saboda tsaka tsaki tare da acetic acid. Wannan gishiri yana da ƙimar amfani da masana'antu kawai bayan recrystallization, rabuwa da tsarkakewa.