1. Qeexidda iyo shaqada dhumuc-dhegaha
Waxyaabaha lagu daro ee si weyn u kordhin kara daxalka rinjiga biyaha ku salaysan waxaa loo yaqaan dhumuc-dhegeeyayaasha.
Dhumuc-yareyaashu waxay door muhiim ah ka ciyaaraan wax soo saarka, kaydinta iyo dhismaha dahaarka.
Shaqada ugu weyn ee dhumuc-dhegeeyaha waa inuu kordhiyo dahaarka dahaarka si uu u buuxiyo shuruudaha marxaladaha kala duwan ee isticmaalka. Si kastaba ha ahaatee, dahaarka uu u baahan yahay dahaarka marxaladaha kala duwan waa ka duwan yahay. Tusaale:
Inta lagu jiro habka kaydinta, waxaa la jecel yahay in la yeesho daxal sare si looga hortago in midabka uu dego;
Inta lagu jiro hawsha dhismaha, waxaa la jecel yahay in la helo isku-dhaf dhexdhexaad ah si loo hubiyo in rinjigu uu leeyahay cadaymo wanaagsan iyada oo aan lahayn rinji xad-dhaaf ah;
Dhismaha ka dib, waxaa la rajeynayaa in viscosity-gu uu si dhakhso ah ugu soo laaban karo viscosity sare ka dib dib u dhac waqti gaaban ah (habka siman) si looga hortago fadhiisashada.
Dareeraha dahaarka biyaha ku jira waa mid aan ahayn Newtonian.
Marka uu dheecanka rinjigu hoos u dhaco marka uu kordho xoogga xiiritaanka, waxaa loo yaqaan dareere pseudoplastic ah, inta badan rinjiguna waa dareere pseudoplastic ah.
Marka dhaqanka socodka ee dareeraha beenta ah uu la xiriiro taariikhdiisa, taasi waa, waxay ku xiran tahay waqtiga, waxaa loo yaqaan dareere thixotropic ah.
Marka aan sameyneyno dahaarka, waxaan inta badan si miyir leh isugu daynaa inaan dahaarka ka dhigno mid thixotropic ah, sida ku darista waxyaabaha lagu daro.
Marka dahaarka uu ku habboon yahay, wuxuu xallin karaa iska hor imaadka marxaladaha kala duwan ee dahaarka, wuxuuna dabooli karaa baahiyaha farsamo ee kala duwanaanta dahaarka ee marxaladaha kaydinta, heerka dhismaha, iyo qallajinta.
Qaar ka mid ah dhumuc-yareyaashu waxay rinjiga siin karaan thixotropy sare, si uu u yeesho viscosity sare marka uu nasto ama heer xiirid hooseeya (sida kaydinta ama rarista), si looga hortago in midabka rinjiga ku jira uu dego. Iyo heerka xiirid sare (sida habka dahaarka), wuxuu leeyahay viscosity hooseeya, si dahaarka uu u yeesho socod iyo simitaan ku filan.
Thixotropy waxaa lagu matalaa tusmada thixotropic TI waxaana lagu cabbiraa Brookfield viscometer.
TI=jilicsanaanta (lagu cabbiray 6r/daqiiqo)/jilicsanaanta (lagu cabbiray 60r/daqiiqo)
2. Noocyada dhumuc-sameeyayaasha iyo saameyntooda ku aaddan sifooyinka dahaarka
(1) Noocyada Marka laga eego halabuurka kiimikada, dhumuc-dhejiyeyaasha waxaa loo qaybiyaa laba qaybood: organic iyo inorganic.
Noocyada aan dabiiciga ahayn waxaa ka mid ah bentonite, attapulgite, aluminium magnesium silicate, lithium magnesium silicate, iwm., noocyada dabiiciga ah sida methyl cellulose, hydroxyethyl cellulose, polyacrylate, polymethacrylate, acrylic acid ama methyl Acrylic homopolymer ama copolymer iyo polyurethane iwm.
Marka laga eego saameynta sifooyinka rheological ee dahaarka, dhumuc-yarayaasha waxaa loo qaybiyaa dhumuc-yarayaasha thixotropic iyo dhumuc-yarayaasha isku-xidhka ah. Marka laga eego shuruudaha waxqabadka, xaddiga dhumuc-yaraha waa inuu yaraadaa saameynta dhumuc-yaraantana waa wanaagsan tahay; ma fududa in ensaymyadu ay wiiqaan; marka heerkulka ama qiimaha pH ee nidaamku isbeddelo, dhumuc-yaraanta dahaarka si weyn looma dhimi doono, midabka iyo buuxintana lama burburin doono. ; Xasillooni kaydin oo wanaagsan; haynta biyaha oo wanaagsan, ma jiro ifafaale xumbo leh oo muuqda iyo saameyn xun oo aan ku yeelanayn waxqabadka filimka dahaarka.
①Qafiifiye unugyo ah
Qalabka dhumucda cellulose-ka ee loo isticmaalo dahaarka waa inta badan methylcellulose, hydroxyethylcellulose iyo hydroxypropylmethylcellulose, labada dambena si caadi ah ayaa loo isticmaalaa.
Hydroxyethyl cellulose waa badeeco laga helo beddelka kooxaha hydroxyl ee cutubyada gulukooska ee cellulose dabiiciga ah kooxaha hydroxyethyl. Tilmaamaha iyo moodooyinka badeecadaha waxaa inta badan lagu kala saaraa heerka beddelka iyo dheellitirka.
Noocyada hydroxyethyl cellulose waxaa sidoo kale loo qaybiyaa nooca kala dirida caadiga ah, nooca kala firdhinta degdega ah iyo nooca xasilloonida bayoolojiga. Marka laga hadlayo habka loo isticmaalo, hydroxyethyl cellulose waxaa lagu dari karaa marxalado kala duwan habka wax soo saarka dahaarka. Nooca kala firdhinta degdega ah waxaa si toos ah loogu dari karaa qaab budo qalalan. Si kastaba ha ahaatee, qiimaha pH ee nidaamka ka hor inta aan la darin waa inuu ka yar yahay 7, inta badan sababtoo ah hydroxyethyl cellulose si tartiib tartiib ah ayuu ugu milmaa qiimaha pH-ga hooseeya, waxaana jira waqti ku filan oo biyuhu ku galaan gudaha walxaha, ka dibna qiimaha pH-ga ayaa la kordhiyaa si uu si dhakhso ah u milmo. Tallaabooyinka u dhigma waxaa sidoo kale loo isticmaali karaa in lagu diyaariyo isku-darka xalka xabagta oo lagu daro nidaamka dahaarka.
Hydroxypropyl methylcellulosewaa badeeco laga helo iyadoo lagu beddelayo kooxda hydroxyl ee ku jirta cutubka gulukooska ee cellulose-ka dabiiciga ah koox methoxy ah, halka qaybta kalena lagu beddelayo koox hydroxypropyl ah. Saamaynteeda dhumucda waxay asal ahaan la mid tahay tan hydroxyethyl cellulose. Waana u adkaysta burburka enzymatic, laakiin milmideeda biyuhu ma fiicna sida tan hydroxyethyl cellulose, waxayna leedahay faa'iido darro ah in la jaro marka la kululeeyo. Hydroxypropyl methylcellulose-ka dusha sare lagu daweeyay, si toos ah ayaa loogu dari karaa biyaha marka la isticmaalo. Ka dib markaad walaaqdo oo aad kala firdhiso, ku dar walxaha alkaline sida biyaha ammonia si aad u hagaajiso qiimaha pH ilaa 8-9, oo walaaq ilaa ay si buuxda u milmaan. Hydroxypropyl methylcellulose iyada oo aan lahayn daaweyn dusha sare ah, waxaa lagu qooyi karaa oo lagu barari karaa biyo kulul oo ka sarreeya 85°C ka hor inta aan la isticmaalin, ka dibna lagu qaboojin karaa heerkulka qolka, ka dibna lagu walaaqo biyo qabow ama biyo baraf ah si ay si buuxda u milmaan.
②Qafiifiye aan dabiici ahayn
Noocan dhumuc-dheere ah wuxuu inta badan yahay qaar ka mid ah alaabada dhoobada firfircoon, sida bentonite, dhoobada magnesium aluminium silicate, iwm. Waxaa lagu gartaa in marka laga soo tago saameynta dhumuc-dheere, ay sidoo kale leedahay saameyn ganaax wanaagsan, waxay ka hortagi kartaa quusitaanka, mana saameyn doonto iska caabbinta biyaha ee dahaarka. Ka dib marka dahaarka la qalajiyo oo loo sameeyo filim, wuxuu u shaqeeyaa sidii buuxin filimka dahaarka, iwm. Arrinta aan fiicnayn ayaa ah inay si weyn u saameyn doonto heerka dahaarka.
③ Dhumucda polymer-ka ee synthetic-ka ah
Dhumuceeyayaasha polymer-ka ee synthetic-ga ah waxaa inta badan loo isticmaalaa acrylic iyo polyurethane (dhumuciyeyaasha isku-dhafka ah). Dhumuceeyayaasha acrylic-ga ah badanaa waa polymers-ka acrylic-ga oo ka kooban kooxaha carboxyl. Biyaha leh qiimaha pH ee 8-10, kooxda carboxyl-ku way kala baxdaa oo way barartaa; marka qiimaha pH-gu ka weynaado 10, waxay ku milmaysaa biyaha waxayna lumisaa saameynta dhumucda, sidaa darteed saameynta dhumucdu aad bay ugu nugul tahay qiimaha pH-ga.
Habka dhumucda ee dhumucda acrylate-ka ayaa ah in walxaha ay ku milmi karaan dusha sare ee walxaha latex-ka ee rinjiga ku jira, isla markaana ay sameeyaan lakab dahaadh ah ka dib bararka alkali, kaas oo kordhiya mugga walxaha latex-ka, carqaladeeya dhaqdhaqaaqa Brownian-ka ee walxaha, isla markaana kordhiya dheellitirka nidaamka rinjiga. ; Marka labaad, bararka dhumucda wuxuu kordhiyaa dheellitirka wejiga biyaha.
(2) Saamaynta dhumuc-dhegeeyaha ku leeyahay sifooyinka dahaarka
Saamaynta nooca dhumuc-sameeyaha ku leeyahay sifooyinka rheological ee dahaarka waa sida soo socota:
Marka xaddiga dhumuc-dhejinta uu kordho, dheellitirka joogtada ah ee rinjiga ayaa si weyn u kordha, isbeddelka isbeddelka dheellitirkana asal ahaan waa mid isku mid ah marka la mariyo xoog xiir ah oo dibadda ah.
Saamaynta dhumuc-dhejinta, dheq-dhejinta rinjiga ayaa si degdeg ah hoos ugu dhacda marka la mariyo xoog xiir ah, taasoo muujinaysa qallooca.
Iyada oo la adeegsanayo dhumuc-qafiye cellulose ah oo wax laga beddelay (sida EBS451FQ), heerarka jarista sare, dheellitirku wali wuu sarreeyaa marka qaddarku badan yahay.
Iyada oo la adeegsanayo walxaha isku dhafan ee polyurethane (sida WT105A), heerarka jarista sare, dheellitirku wali wuu sarreeyaa marka xaddigu badan yahay.
Iyadoo la adeegsanayo walxaha qariya acrylic-ga (sida ASE60), inkastoo isku-dhafka aan joogtada ahayn uu si degdeg ah u kordho marka xaddigu weyn yahay, isku-dhafka si dhakhso ah ayuu hoos ugu dhacaa heerka xiirashada sare.
3. Dhumucda isku xidhka
(1) habka dhumucda
Qalabka dhumucsan ee acrylic-ka ee cellulose ether iyo alkali-bararsan waxay kaliya dhumuc karaan marxaladda biyaha, laakiin saameyn dhumuc leh kuma yeelan karaan qaybaha kale ee rinjiga ku salaysan biyaha, mana sababi karaan isdhexgal muhiim ah oo u dhexeeya midabada rinjiga ku jira iyo walxaha emulsion-ka, sidaa darteed rheology-ga rinjiga lama hagaajin karo.
Dhumucyada isku xidhka ah waxaa lagu gartaa in marka laga soo tago dhumucda fuuq-baxa, ay sidoo kale dhumuc weynaadaan iyada oo loo marayo isku xidhka dhexdooda, walxaha kala firdhisan, iyo qaybaha kale ee nidaamka. Xiriirkani wuxuu kala go'aa heerarka xiirashada sare wuxuuna dib ugu xidhmaa heerarka xiirashada hooseeya, taasoo u oggolaanaysa in la hagaajiyo rheology-ga dahaarka.
Habka dhumucda ee dhumucda isku xidhka ayaa ah in molecule-kiisu yahay silsilad hydrophilic toosan, oo ah isku-dhis polymer ah oo leh kooxo lipophilic ah labada darafba, taas oo ah, waxay leedahay kooxo hydrophilic iyo hydrophobic ah oo ku jira qaab-dhismeedka, sidaas darteed waxay leedahay astaamaha molecules-ka surfactant. dabeecadda. Molecules-ka dhumucda noocan oo kale ah ma aha oo kaliya inay qoyaan oo bararaan si ay u qariyaan wejiga biyaha, laakiin sidoo kale waxay sameeyaan micelles marka fiirsashada xalka biyaha ay ka badan tahay qiimo gaar ah. Micelles-ku waxay la xiriiri karaan walxaha polymer-ka ee emulsion-ka iyo walxaha midabka ee nuugay kala-baxa si ay u sameeyaan qaab-dhismeed shabakad saddex-geesood ah, waana kuwo isku xiran oo isku dheggan si loo kordhiyo dheellitirka nidaamka.
Waxa ka sii muhiimsan ayaa ah in isku-xirnaantani ay ku jiraan xaalad isku dheelitirnaan firfircoon, iyo in jiirkaas la xiriira ay hagaajin karaan boosaskooda marka ay la kulmaan xoogagga dibadda, si dahaarka uu u yeesho sifooyin siman. Intaa waxaa dheer, maadaama molecule-ku uu leeyahay dhowr micelles, qaab-dhismeedkani wuxuu yareeyaa u janjeersiga molecules-ka biyaha inay u guuraan sidaas darteedna wuxuu kordhiyaa dheellitirka wejiga biyaha.
(2) Doorka dahaarka
Inta badan dhumuc-dhejiyeyaasha isku xidhka ah waa polyurethanes, miisaankooda molecular-ka ee qaraabaduna waa inta u dhaxaysa 103-104 darajo oo cabbir ah, laba darajo oo cabbir ah oo ka hooseeya polyacrylic acid-ka caadiga ah iyo dhumuc-dhejiyeyaasha cellulose oo leh miisaanno molecular oo qaraabadoodu u dhexeeyaan 105-106. Sababtoo ah miisaanka molecular-ka ee hooseeya, kororka mugga wax ku oolka ah ka dib fuuq-baxa ayaa yar, sidaa darteed qalooca viscosity-giisu waa mid siman marka loo eego dhumuc-dhejiyeyaasha aan isku xidhnayn.
Sababtoo ah miisaanka molecular-ka ee hooseeya ee dhumuc-dhegaha isku xidhka, isku-xidhka molecular-ka ee wejiga biyaha waa mid xaddidan, sidaa darteed saameyntiisa dhumuc-dhegaha ee wejiga biyaha ma aha mid muhiim ah. Heerka heerka jarista hoose, beddelka isku-xidhka ee u dhexeeya molecules-ku waa wax ka badan burburka isku-xidhka ee u dhexeeya molecules-ka, nidaamka oo dhan wuxuu ilaaliyaa xaalad joojin iyo kala-fidin ah, viscosity-guna wuxuu u dhow yahay viscosity-ga dhexdhexaadka kala-fidinta (biyaha). Sidaa darteed, dhumuc-dhegaha isku xidhka wuxuu ka dhigayaa nidaamka rinjiga ku salaysan biyaha inuu muujiyo viscosity hoose marka uu ku jiro gobolka heerka jarista hoose.
Dhumuceeyayaasha isku xidhka ah waxay kordhiyaan tamarta suurtagalka ah ee u dhaxaysa molecules-ka sababtoo ah xiriirka ka dhexeeya walxaha marxaladda kala firdhisan. Sidan, tamar badan ayaa loo baahan yahay si loo jebiyo xiriirka ka dhexeeya molecules-ka heerarka xiirashada sare, xoogga xiirashada ee loo baahan yahay si loo gaaro isku-dhafka xiirashada ayaa sidoo kale ka weyn, sidaas darteed nidaamku wuxuu muujiyaa heer xiirsasho sare heerarka xiirashada sare. Dhumucda muuqata. Dhumucda xiirashada sare ee sare iyo xiirashada hoose ee hoose waxay kaliya kaabi karaan la'aanta dhumuc-dhejiyeyaasha caadiga ah ee sifooyinka rheological ee rinjiga, taas oo ah, labada dhumuc-dhejiye waxaa loo isticmaali karaa isku-darka si loo hagaajiyo dareeraha rinjiga latex. Waxqabadka isbeddelka leh, si loo daboolo shuruudaha dhammaystiran ee dahaarka filimka qaro weyn iyo socodka filimka dahaarka.
Waqtiga boostada: Abriil-28-2024