Sidee loo sameeyaa hydroxyethyl cellulose?

Hydroxyethyl Cellulose (HEC) waa polymer-ka caadiga ah ee biyaha ku milma oo si ballaaran loogu isticmaalo kiimikooyinka maalinlaha ah, dhismaha, dahaarka, daawada, cuntada iyo warshadaha kale. Waa eter cellulose aan-ionic ahayn oo lagu sameeyay kiimikaad wax ka beddeleysa cellulose dabiiciga ah. Habka wax soo saarka ee cellulose hydroxyethyl waxay ku lug leedahay falcelin kiimiko oo adag, oo ay ku jiraan soo saarista cellulose, daaweynta alkalization, falcelinta etherification, iwm. Kuwa soo socdaa waa hordhac faahfaahsan oo ku saabsan habka wax soo saarka.

1. Xulashada alaabta ceeriin iyo soo saarista cellulose
Maaddada aasaasiga ah ee cayriin ee hydroxyethyl cellulose waa cellulose dabiiciga ah, taas oo inta badan ka timaada alwaax, suuf ama fiilooyinka dhirta kale. Maaddada cellulose ee ku jirta gidaarada unugyada dhirta ayaa aad u sarreeya, cellulose saafi ah ayaa laga soo saari karaa qalabkan dabiiciga ah iyada oo la adeegsanayo farsamo ama kiimiko. Habka soo saarista waxaa ka mid ah burburinta, ka saarista wasakhda (sida lignin, hemicellulose), bleaching iyo tallaabooyin kale.

Soosaarista Cellulose: cellulose dabiiciga ah waxaa badanaa lagu daaweeyaa si farsamaysan ama kiimiko ah si looga saaro walxaha aan cellulose ahayn si loo helo cellulose nadiif ah oo sarreeya. Fiber cudbi, saxarka alwaax, iwm. dhamaantood waxay noqon karaan ilo caadi ah oo laga helo alaabta ceeriin. Inta lagu jiro habka daawaynta, alkali (sida sodium hydroxide) ayaa loo isticmaalaa in lagu caawiyo kala dirida qaybaha aan cellulose ahayn, inta soo hartayna waxay u badan tahay cellulose.
2. Daawaynta alkalisation
cellulose-ka la safeeyey waa in marka hore alkalized. Talaabadani waa in la sameeyo kooxaha hydroxyl ee silsiladda molecular cellulose mid firfircoon si ay si fudud uga falceliyaan wakiilka etherifying. Tallaabooyinka ugu muhiimsan ee daaweynta alkalization waa sida soo socota:

Falcelinta cellulose leh alkali: cellulose waxaa lagu qasaa alkali xooggan (badanaa sodium hydroxide) si loo soo saaro alkali cellulose (Alkali Cellulose). Habkan waxaa badanaa lagu fuliyaa meel dhexdhexaad ah oo biyo ah. Alkali cellulose waa sheyga falcelinta cellulose iyo sodium hydroxide. Walaxdani waxay leedahay qaab-dhismeed dabacsan iyo falcelin sare, taas oo ku habboon falcelinta etherification ee xiga.
Habka alkalization inta badan waxay ku dhacdaa heerkulka ku habboon iyo huurka, badiyaa inta u dhaxaysa 20 ℃ ~ 30 ℃ dhowr saacadood si loo hubiyo in kooxaha hydroxyl ee molecules cellulose ay si buuxda u shaqeeyaan.

3. Falcelinta Etherification
Etherification waa tallaabo fure u ah soo saarista hydroxyethyl cellulose. Hydroxyethyl cellulose waxaa la soo saaraa iyadoo ka falcelinaysa cellulose alkali leh ethylene oxide si ay u soo bandhigto kooxaha hydroxyethyl. Tallaabooyinka gaarka ah waa sida soo socota:

Falcelinta ethylene oxide: Alkali cellulose waxa uu la falgalaa xaddi go'an oo ah ethylene oxide hoostiisa heerkulka iyo xaaladaha cadaadiska qaarkood. Qaab dhismeedka giraanta ee ethylene oxide wuxuu furmaa si uu u sameeyo dammaanad ether ah, wuxuu la falgalaa kooxaha hydroxyl ee ku jira molecules cellulose, wuxuuna soo bandhigaa kooxaha hydroxyethyl (-CH2CH2OH). Nidaamkani wuxuu hagaajin karaa heerka etherification isagoo xakameynaya xaaladaha falcelinta (sida heerkulka, cadaadiska, iyo waqtiga).
Dareen-celinta waxaa badanaa lagu fuliyaa jawi alkaline ah si loo hubiyo waxtarka etherification. Heerkulka falcelinta guud ahaan waa 50 ℃ ~ 100 ℃, iyo waqtiga falcelinta waa dhowr saacadood. Iyadoo la hagaajinayo qadarka ethylene oxide, heerka beddelka badeecada ugu dambeysa waa la xakameyn karaa, taas oo ah, inta kooxood ee hydroxyl ee unugyada cellulose ayaa lagu beddelaa kooxaha hydroxyethyl.

4. Dhexdhexaadin iyo dhaqid
Ka dib marka falcelinta etherification la dhammeeyo, walxaha alkaline ee nidaamka falcelinta waxay u baahan yihiin in la dhexdhexaadiyo. Dhexdhexaadiyeyaasha sida caadiga ah loo isticmaalo waa walxaha acidic, sida acetic acid ama hydrochloric acid. Habka dhexdhexaadinta ayaa ka takhalusi doona alkali-ka xad-dhaafka ah ee cusbada, taas oo aan saameyn ku yeelan doonin waxqabadka alaabta.

Dareen-celinta dhexdhexaadinta: Ka saar badeecada reactor-ka oo ku dar qadar ku habboon oo aashito ah si aad u dhexdhexaadiso ilaa qiimaha pH ee nidaamka uu gaaro dhexdhexaad. Habkani ma aha oo kaliya in uu meesha ka saaro alkali haraaga, laakiin sidoo kale wuxuu yareeyaa saameynta falcelinta by-products ee waxqabadka hydroxyethyl cellulose.

Dhaqidda iyo fuuq-baxa: Alaabta dhexdhexaadka ah waxay u baahan tahay in la dhaqo dhowr jeer, badanaa biyo ama ethanol iyo dareerayaasha kale si loo dhaqo wasakhda haraaga ah iyo alaabta ka soo baxda. Alaabta la dhaqay waxaa fuuqbaxa centrifugation, filter filter iyo habab kale si loo yareeyo qoyaanka.

5. Qalajinta iyo burburinta
Ka dib markii la dhaqo iyo fuuqbaxa, hydroxyethyl cellulose ayaa weli ku jira xaddi qoyaan ah oo u baahan in la sii qalajiyo. Habka qalajinta waxaa lagu samayn karaa qalajinta hawada ama faakuum qalajinta si loo hubiyo in alaabtu leedahay xasilooni wanaagsan inta lagu jiro kaydinta iyo isticmaalka.

Qalajinta: Ku qallaji alaabta heerkul gaar ah (badanaa ka hooseeya 60°C) si aad meesha uga saarto qoyaanka haraaga ah. Heerkulka qalajinta waa inuusan noqon mid aad u sarreeya, haddii kale waxay keeni kartaa hoos u dhac ku yimaada alaabada oo saameyn ku yeelata waxqabadkeeda.

Burburinta iyo baarista: Hydroxyethyl cellulose-ka qallalan inta badan waxa uu ku jiraa baloogyada ama kuuskuusan, waana in la burburiyaa si loo helo budo fiican. Badeecada la jajabiyey ayaa sidoo kale u baahan in la baaro si loo helo qaybinta cabbirka qaybinta buuxinta shuruudaha si loo hubiyo in ay milmi iyo kala firdhiso codsiyada la taaban karo.

6. Tijaabinta iyo baakaynta alaabta kama dambaysta ah
Wax soo saarka ka dib, hydroxyethyl cellulose waxay u baahan tahay in lagu tijaabiyo tayada si loo hubiyo in tilmaamayaasha waxqabadkeedu ay buuxiyaan shuruudaha caadiga ah. Alaabooyinka tijaabinta badanaa waxaa ka mid ah:

Cabbirka Viscosity: Viscosity of hydroxyethyl cellulose ka dib marka lagu milmo biyaha waa tilmaame tayo leh oo muhiim ah, kaas oo saameeya isticmaalkiisa dahaarka, dhismaha, kiimikooyinka maalinlaha ah iyo qaybaha kale.
Maaddada qoyaanka: Tijaabi nuxurka qoyaanka alaabta si aad u hubiso xasilloonida kaydinta.
Darajada beddelka (DS) iyo beddelka molarka (MS): Go'aami heerka beddelka iyo beddelka molarka ee sheyga iyada oo loo marayo falanqaynta kiimikaad si loo hubiyo saamaynta falcelinta etherification.
Ka dib marka la gudbo imtixaanka, hydroxyethyl cellulose waxaa lagu baakadeeyaa budo ama badeecooyin granular ah, badanaa bacaha aan qoyaanka lahayn ama bacaha waraaqaha si looga ilaaliyo inuu qoyaan ama wasakheeyo.

Habka wax soo saarka ee cellulose hydroxyethyl inta badan waxaa ka mid ah tallaabooyinka soo saarista cellulose, daaweynta alkalization, falcelinta etherification, dhexdhexaadinta iyo dhaqidda, qalajinta iyo burburinta. Nidaamka oo dhan wuxuu ku xiran yahay alkalization iyo etherification ee falcelinta kiimikada, iyo cellulose waxaa la siiyaa biyo wanaagsan milmayn iyo sifooyinka dhumuc by soo bandhigid kooxaha hydroxyethyl. Hydroxyethyl cellulose waxaa si ballaaran loo isticmaalaa in warshado badan, sida dhumucdiisuna for daahan, wakiilka biyaha-haysta qalabka dhismaha, xasilinta ee alaabta kiimikada maalin kasta, iwm Xiriir kasta oo habka wax soo saarka u baahan yahay in si adag loo xakameeyo si loo hubiyo tayada sare iyo waxqabadka xasilloon. ee alaabta.