1. Qeexida iyo shaqada dhumucda
Waxyaabaha lagu daro oo si weyn u kordhin kara viscosity ee rinjiga biyaha ku salaysan waxaa loo yaqaan dhumucyada.
Dhumucdiisuna waxay door muhiim ah ka ciyaaraan wax soo saarka, kaydinta iyo dhismaha dahaarka.
Shaqada ugu weyn ee dhumucdiisu waa in la kordhiyo viscosity ee daahan si loo buuxiyo shuruudaha marxaladaha kala duwan ee isticmaalka. Si kastaba ha ahaatee, viscosity looga baahan yahay daahan marxalado kala duwan waa ka duwan yahay. Tusaale:
Inta lagu jiro habka kaydinta, waa suurad wacan in la helo viscosity sare si looga hortago in midabku uu dego;
Inta lagu jiro habka dhismaha, waa suurad wacan in la helo viscosity dhexdhexaad ah si loo hubiyo in rinji uu leeyahay burush wanaagsan oo aan lahayn rinji xad dhaaf ah;
Dhismaha ka dib, waxaa la rajeynayaa in viscosity uu si dhakhso ah ugu soo laaban karo viscosity sare ka dib wakhti gaaban (habraaca heerka) si looga hortago hoos u dhaca.
Dheecaannada dahaarka biyuhu waa kuwo aan Newtonian ahayn.
Marka mawjadaha rinjigu hoos u dhaco kororka xoogga xiirta, waxaa loo yaqaan dareeraha pseudoplastic, inta badan rinjiga waa dareere pseudoplastic ah.
Marka habdhaqanka qulqulka dareeraha pseudoplastic uu la xiriiro taariikhdiisa, taas oo ah, waxay ku xiran tahay waqti, waxaa loo yaqaannaa dareeraha thixotropic.
Marka la soo saaro dahaarka, waxaan inta badan si miyir leh isku day in aan samayno daahan thixotropic, sida ku darista daro.
Marka thixotropy ee dahaarka ay ku habboon tahay, waxay xallin kartaa is burinaya marxaladaha kala duwan ee daahan, waxayna dabooli kartaa baahida farsamada ee viscosity kala duwan ee daahan ee kaydinta, heerka dhismaha, iyo marxaladaha qalajinta.
Qaar ka mid ah dhumucyada waxay ku siin karaan rinjiga thixotropy sare, si uu u yeesho viscosity sare marka nasashada ama heerka dhogorta hoose (sida kaydinta ama gaadiidka), si looga hortago in midabka rinjiga uu dejiyo. Oo hoos heerka xiirid sare (sida habka daahan), waxa uu leeyahay viscosity hoose, si daahan ayaa socodka ku filan iyo heerka.
Thixotropy waxaa matala thixotropic index TI waxaana lagu cabbiraa viskometer Brookfield.
TI= viscosity (waxaa lagu qiyaasaa 6r/min)/mujisnimo (oo lagu qiyaasay 60r/min)
2. Noocyada dhumucyada iyo saamaynta ay ku leeyihiin sifooyinka daahan
(1) Noocyada Marka la eego halabuurka kiimikada, dhumucdiisuna waxay u qaybsantaa laba qaybood: organic iyo inorganic.
Noocyada inorganic waxaa ka mid ah bentonite, attapulgite, aluminium magnesium silicate, lithium magnesium silicate, iwm, noocyada organic sida methyl cellulose, hydroxyethyl cellulose, polyacrylate, polymethacrylate, acrylic acid ama methyl Acrylic homopolymer ama copolymer iyo polyurethane iwm.
Laga soo bilaabo aragtida saamaynta ku leh guryaha rheological ee daahan, dhumucdiisuna waxay u qaybsan yihiin dhumucyada thixotropic iyo dhumucyada associative. Marka la eego shuruudaha waxqabadka, qadarka dhumucdiisu waa inay yaraataa oo saamaynta dhumucda waa wanaagsan tahay; ma fududa in ay nabaad guuraan enzymes; marka heerkulka ama qiimaha pH ee nidaamka isbeddelo, viscosity ee daahan si weyn loo dhimi maayo, iyo midabka iyo buuxinta aan la flocculated doonaa. ; Dejinta kaydinta wanaagsan; biyo-hayn wanaagsan, ma jirto ifafaale xumbo cad oo aan wax saameyn ah ku yeelan waxqabadka filimka daahan.
Dhumucdiisuna waxay tahay Cellulose
Dhumucyada cellulose-ka ee loo isticmaalo dahaarka waxay u badan yihiin methylcellulose, hydroxyethylcellulose iyo hydroxypropylmethylcellulose, labada dambena si caadi ah ayaa loo isticmaalaa.
Hydroxyethyl cellulose waa badeecad la helay iyadoo lagu beddelayo kooxaha hydroxyl ee unugyada gulukooska ee cellulose dabiiciga ah oo leh kooxaha hydroxyethyl. Tilmaamaha iyo moodooyinka alaabooyinka waxaa inta badan lagu kala soocaa iyadoo loo eegayo heerka beddelka iyo viscosity.
Noocyada cellulose hydroxyethyl sidoo kale waxay u qaybsan yihiin nooca kala dirida caadiga ah, nooca fidinta degdega ah iyo nooca xasiloonida noolaha. Ilaa hadda sida habka loo isticmaalo, hydroxyethyl cellulose waxaa lagu dari karaa marxalado kala duwan ee habka wax soo saarka daahan. Nooca degdega ah ee degdega ah ayaa si toos ah loogu dari karaa qaabka budada qalalan. Si kastaba ha ahaatee, qiimaha pH ee nidaamka ka hor inta aan lagu darin waa inuu noqdaa mid ka yar 7, sababtoo ah hydroxyethyl cellulose ayaa si tartiib ah u milmaan qiimihiisu hooseeya, waxaana jira wakhti ku filan oo biyuhu u galaan gudaha qaybaha, ka dibna qiimaha pH waa la kordhiyaa si ay si dhakhso ah u milmaan. Tallaabooyinka u dhigma ayaa sidoo kale loo isticmaali karaa si loo diyaariyo fiirsashada gaar ah ee xal koollada oo lagu daro nidaamka daahan.
Hydroxypropyl methylcellulosewaa shey la helay iyadoo lagu beddelayo kooxda hydroxyl ee unugga gulukooska ee cellulose dabiiciga ah oo leh koox methoxy ah, halka qaybta kale lagu beddelay koox hydroxypropyl ah. Saameynteeda dhumucdeedu waxay asal ahaan la mid tahay tan hydroxyethyl cellulose. Waxayna adkaysi u leedahay xaalufka enzymatic, laakiin milmayntiisa biyuhu uma fiicna sida ta hydroxyethyl cellulose, waxayna leedahay khasaare gelling marka la kululeeyo. Hydroxypropyl methylcellulose oogada lagu daaweeyay, waxaa si toos ah loogu dari karaa biyaha marka la isticmaalo. Ka dib markaad walaaqdo oo kala firdhiso, ku dar walxaha alkaline sida biyaha ammonia si aad u hagaajisid qiimaha pH ilaa 8-9, oo walaaq ilaa si buuxda loo kala diro. Hydroxypropyl methylcellulose iyada oo aan la daaweyn dusha sare, waa la qooyay oo lagu barari karaa biyo kulul oo ka sarreeya 85 ° C ka hor inta aan la isticmaalin, ka dibna la qaboojiyo heerkulka qolka, ka dibna lagu walaaqo biyo qabow ama biyo baraf ah si ay si buuxda u milmaan.
② Dhumucyada aan organic ahayn
Dhumucda noocan oo kale ah ayaa inta badan ah qaar ka mid ah alaabta dhoobada firfircoon, sida bentonite, magnesium aluminium silicate dhoobo, iwm. Waxaa lagu gartaa in marka lagu daro saameynta dhumucda, waxay sidoo kale leedahay saameyn ganaax ah oo wanaagsan, waxay ka hortagi kartaa qulqulka, mana saameyn doonto caabbinta biyaha ee daahan. Ka dib markii dahaarka la qalajiyo oo loo sameeyo filim, waxay u shaqeysaa sidii buuxinta filimka dahaarka, iwm. Qodobka aan fiicnayn ayaa ah in ay si weyn u saameyn doonto heerka cabbirka.
③ Dhumucnad polymer-ka synthetic
Dhumucyada polymer synthetic waxaa inta badan loo isticmaalaa akril iyo polyurethane ( dhumucyada associative ). Dhumucyada akril waxay u badan yihiin polymers acrylic oo ay ku jiraan kooxaha karboksylka. Biyaha leh qiimaha pH ee 8-10, kooxda karboksylku way kala qaybsantaa oo waxay noqotaa barar; marka qiimaha pH uu ka weyn yahay 10, waxay ku milmaysaa biyaha waxayna luminaysaa saamaynta dhumucda, markaa saamaynta dhumucdu waxay aad u xasaasi u tahay qiimaha pH.
Habka dhumucdiisuna ee acrylate dhumucdiisuna waa in ay qayb ka mid ah lagu dhejin karaa dusha sare ee qaybaha cinjirka ee rinjiga, oo ay sameeyaan lakab daahan ka dib bararka alkali, taas oo kordhisa mugga qayb ka cinjirka, caqabad ku dhaqdhaqaaqa Brownian ee qayb ka, iyo kordhiyo viscosity ee nidaamka rinjiga. ; Marka labaad, bararka dhumucdiisu waxay kordhisaa viscosity ee wajiga biyaha.
(2) Saamaynta dhumucdu ku leedahay guryaha daahan
Saamaynta nooca dhumucyada ee sifooyinka rheological ee daahan waa sida soo socota:
Marka qadarka dhumucdiisu korodho, mawjadaha taagan ee rinjiga ayaa si aad ah u kordha, isbeddelka viscosity-ka isbeddelkuna wuxuu asal ahaan joogto yahay marka la geliyo xoog xiirid dibadda ah.
Iyada oo saamaynta dhumucdiisuna, viscosity ee rinji si degdeg ah hoos u marka ay hoos yimaadaan xoog xiirid, oo muujinaya pseudoplasticity.
Isticmaalka dhumucda cellulose hydrophobically modified (sida EBS451FQ), ee heerarka xiirid sare, viscosity weli waa sarreeyaa marka qaddarku badan yahay.
Isticmaalka dhumucyada polyurethane-ka associative (sida WT105A), ee heerarka dhogorta sare, viscosity weli wuu sarreeyaa marka qaddarku weyn yahay.
Isticmaalka dhumucyada akriliga ah (sida ASE60), inkasta oo viscosity-ga taagan uu si degdeg ah u kaco marka qaddarku weyn yahay, mawgu wuxuu si degdeg ah hoos ugu dhacayaa heerka dhogorta sare.
3. Dhumucda associative
(1) habka dhumucdi
Ether Cellulose iyo dhumucyada alkali-barari kara oo kaliya waxay adkeyn karaan wajiga biyaha, laakiin wax saameyn ah kuma yeelan karaan qaybaha kale ee rinjiga biyaha ku salaysan, mana keeni karaan isdhexgalka weyn ee u dhexeeya pigments ee rinjiga iyo qaybaha emulsion-ka, sidaa daraadeed rheology ee rinjiga lama hagaajin karo.
Dhumucyada associative waxaa lagu gartaa in marka laga reebo dhumucdi iyada oo loo marayo fuuq-baxa, waxay sidoo kale dhumucdeen iyada oo loo marayo ururada dhexdooda, oo leh qaybo kala firdhiyey, iyo qaybaha kale ee nidaamka. Ururkani wuxuu kala soocaa heerarka sare ee dhogorta wuxuuna dib ula xiriiriyaa heerarka hoose ee dhogorta, taas oo u oggolaanaysa rheology ee dahaarka in la hagaajiyo.
Habka dhumucdiisuna ee dhumucdiisuna associative waa in ay molecule waa silsilad hydrophilic toosan, xarun polymer oo leh kooxaha lipophilic ee labada daraf, taas oo ah, waxa uu leeyahay kooxaha hydrophilic iyo hydrophobic ee qaab-dhismeedka, sidaas darteed waxa uu leeyahay sifooyinka molecules surfactant. dabeecadda. Unugyada dhumucyada noocan oo kale ah ma aha oo kaliya inay nuujiyaan oo bararaan si ay u adkeeyaan wajiga biyaha, laakiin sidoo kale waxay sameeyaan miceles marka xoojinta xalkeeda aqueous ay dhaafto qiimo gaar ah. Miceles-ku waxay la xiriiri karaan qaybaha polymer ee emulsion-ka iyo qaybaha midabada kuwaas oo soo dhejiyay kala-baxa si ay u sameeyaan qaab-dhismeedka shabakad saddex-geesood ah, waxayna isku xiran yihiin oo isku xiran yihiin si loo kordhiyo viscosity nidaamka.
Waxa ka sii muhiimsan waa in ururadani ay ku jiraan xaalad isku dheelitiran oo firfircoon, iyo kuwa la xidhiidha micelles waxay hagaajin karaan boosaskooda marka ay la kulmaan xoogagga dibadda, si dahaarka uu u yeesho sifooyin siman. Intaa waxaa dheer, maadaama molecule uu leeyahay dhowr miceles, qaab-dhismeedkani wuxuu yareynayaa u janjeersiga molecules-ka biyaha si ay u haajiraan oo sidaas awgeed waxay kordhisaa viscosity ee wajiga aqueous.
(2) Doorka dahaarka
Inta badan dhumucyada associative waa polyurethane, iyo miisaankooda molecular ee u dhexeeya 103-104 amarrada cabbirka, laba amar oo ka hooseeya polyacrylic acid iyo dhumucyada cellulose oo leh miisaan qaraabo ah oo u dhexeeya 105-106. Sababtoo ah miisaanka kelli ee hooseeya, korodhka mugga waxtarka leh ka dib fuuq-baxa waa ka yar yahay, sidaas darteed qalooca viscosity waa ka sii fiican yahay kuwa dhumucyada aan la xiriirin.
Sababo la xiriira miisaanka kelli ee hoose ee dhumucda associative, isku xidhiddeeda intermolecular ee marxaladda biyuhu waa xaddidan tahay, markaa saamaynta dhumucdeeda ee wejiga biyaha maaha mid muhiim ah. Marka la eego heerka hoose ee heerka dhogorta, beddelka ururka ee u dhexeeya molecules waa ka badan yahay burburka ururka ee u dhexeeya molecules, nidaamka oo dhan wuxuu ilaaliyaa xannibaad dabiici ah iyo xaalad kala firdhisan, iyo viscosity wuxuu ku dhow yahay viscosity ee dhexdhexaadiyaha firidhsan (biyaha). Sidaa darteed, dhumucda associative waxay ka dhigaysaa nidaamka rinjiga biyaha ku salaysan inuu muujiyo viscosity hoose oo muuqda marka uu ku sugan yahay gobolka heerka dhogorta hoose.
Dhumucyada associative waxay kordhiyaan tamarta suurtagalka ah ee u dhaxaysa molecules sababtoo ah xiriirka ka dhexeeya qaybaha marxaladda kala firdhiyey. Sidan oo kale, tamar badan ayaa loo baahan yahay si loo jebiyo xiriirka ka dhexeeya molecules ee heerarka sare ee dhogorta, iyo xoogga loo baahan yahay si loo gaaro isla culeyska dhogorta ayaa sidoo kale ka weyn, si nidaamku u muujiyo heerka sare ee heerka sare ee heerarka sare. Viscosity muuqda. Viscosity sare ee dhogorta sare iyo viscosity hoose ee dhogorta hoose ayaa kaliya ka dhigi kara la'aanta dhumucyada caadiga ah ee sifooyinka rheological ee rinjiga, taas oo ah, labada dhumuc ayaa loo isticmaali karaa isku darka si loo hagaajiyo dareeraha rinjiga cinjirka. Waxqabadka isbeddelka ah, si loo daboolo shuruudaha dhammaystiran ee daahan ee filim qaro weyn iyo socodka filimka dahaarka.
Waqtiga boostada: Abriil-28-2024