Polyanionic cellulose (PAC) waa derivative cellulose biyo-milmi leh in uu leeyahay tiro balaadhan oo ah codsiyada warshadaha kala duwan, gaar ahaan berrinka qodista dareere ee warshadaha saliidda iyo gaaska. Waxaa lagu yaqaanaa sifooyinka rheological ee aadka u wanaagsan, xasilloonida sare iyo la jaanqaadka waxyaabaha kale ee lagu daro. Soo saarista cellulose polyanionic waxay ku lug leedahay dhowr tillaabo, oo ay ku jiraan soo saarista cellulose, wax ka beddel kiimikaad, iyo nadiifin.
1. Soo saarista cellulose:
Maaddada bilawga ah ee cellulose polyanionic waa cellulose, polymer dabiici ah oo laga helo gidaarada unugyada dhirta. Cellulose waxaa laga soo saari karaa qalabyada kala duwan ee dhirta, sida saxarka alwaax, suufka suufka, ama dhirta kale ee fibros ah. Habka soo saarista waxaa ka mid ah tallaabooyinka soo socda:
A. Diyaarinta alaabta ceeriin:
Qalabka dhirta la xushay waa la sii daayay si looga saaro wasakhda sida lignin, hemicellulose iyo pectin. Tan badanaa waxaa lagu dhammeeyaa isku darka daawaynta makaanikada iyo kiimikada.
b. garaacid:
Walaxda la sii daweeyay ayaa markaa la jiidaa, habkaas oo jebiya fiilooyinka cellulose. Hababka caamka ah ee garaacista waxaa ka mid ah pulping kraft iyo sulfite pulping, mid kastaa wuxuu leeyahay faa'iidooyin iyo faa'iido darrooyinkiisa.
C. Kala saarida cellulose:
Maaddada saxarka waxaa lagu farsameeyaa si loo kala saaro fiilooyinka cellulosic. Tani waxay badanaa ku lug leedahay habka dhaqidda iyo nadiifinta si loo helo walxo cellulosic saafi ah.
2. Wax ka beddel kiimikaad:
Marka cellulose la helo, waxaa kiimiko ahaan wax laga beddelay si loo soo bandhigo kooxaha anionic, taas oo u beddeleysa cellulose polyanionic. Habka caadiga ah ee loo isticmaalo ujeedadan waa etherification.
A. Etherification:
Etherification waxay ku lug leedahay falcelinta cellulose leh wakiilka etherifying si loo soo bandhigo isku xirka ether. Xaaladda cellulose polyanionic, kooxaha karboksymethyl ayaa inta badan la soo bandhigaa. Tan waxaa lagu gaaraa falcelinta sodium monochloroacetate iyada oo ay jirto kiciye aasaasiga ah.
b. Falcelinta Carboxymethylation:
Dareen-celinta karboxymethylation waxay ku lug leedahay beddelka atamka hydrogen-ka ee kooxaha hydroxyl ee cellulose oo leh kooxaha karboxymethyl. Dareen-celintani waxay muhiim u tahay soo bandhigida kharashyada anionic ee laf dhabarta cellulose.
C. dhexdhexaadin:
Karboxymethylation ka dib, badeecada waa la dhexdhexaadin si loogu beddelo kooxda karboxymethyl ion karboxylate. Talaabadani waxay muhiim u tahay samaynta cellulose-ka polyanionic ee biyaha-milmi kara.
3. Nadiifinta:
Cellulose-ka wax laga beddelay ayaa markaa la nadiifiyaa si looga saaro badeecooyinka, kiimikooyinka aan falcelinta lahayn, iyo wixii wasakh ah ee saameeya waxqabadkeeda codsi gaar ah.
A. dhaqid:
Alaabooyinka si fiican ayaa loo nadiifiyaa si looga saaro fal-celiyeyaasha xad-dhaafka ah, cusbada iyo wasakhda kale. Biyaha ayaa inta badan loo isticmaalaa ujeedadan.
b. Qalajinta:
Cellulose-ka polyanionic ee la safeeyey ayaa markaa la qalajiyey si loo helo badeecada ugu dambeysa oo ah budo ama qaab granular ah.
4. Xakamaynta tayada:
Tallaabooyinka xakamaynta tayada ayaa lafuliyaa inta lagu guda jiro habka wax soo saarka si loo hubiyo in cellulose-ka polyanionic ee ka soo baxa uu buuxiyo shuruudaha loo baahan yahay. Tani waxay ku lug leedahay tijaabinta miisaanka kelli, heerka beddelka iyo cabbirrada kale ee khuseeya.
5. Codsiga:
Polyanionic cellulose waxay leedahay codsiyo warshado kala duwan, ugu horrayn hababka dareeraha qodista ee qaybta saliidda iyo gaaska. Waxay u shaqeysaa sidii tackifier, wakiilka xakamaynta luminta dareeraha iyo ka hortagga shale, hagaajinta waxqabadka guud ee dareeraha qodista. Codsiyada kale waxaa ka mid ah warshadaha cuntada iyo dawooyinka halkaas oo milanka biyaha iyo sifooyinka rheological ay bixiyaan faa'iidooyin.
Polyanionic cellulose waa soosaar cellulose ah oo kala duwan oo qiimo leh kaas oo wax soo saarkiisu u baahan yahay taxane si fiican loo qeexay. Soo saarista cellulose ee walxaha dhirta, wax ka beddelka kiimikada iyada oo loo marayo etherification, nadiifinta iyo xakamaynta tayada ayaa ah qaybo ka mid ah habka wax soo saarka. Ka-soo-baxa polyanionic cellulose waa qayb muhiim ah oo ka mid ah codsiyada warshadaha kala duwan, caawinta hagaajinta waxqabadka iyo shaqeynta qaababka kala duwan. Maaddaama warshaduhu ay sii wadaan horumarinta, baahida loo qabo soosaarayaasha cellulose ee gaarka ah sida polyanionic cellulose ayaa la filayaa inay koraan, wadista cilmi baarista sii socota iyo horumarinta tignoolajiyada wax ka beddelka cellulose iyo codsiyada.
Waqtiga boostada: Dec-26-2023