Cov khoom ntawm Cationic Cellulose Ether Solution

Lub dilute tov zog ntawm high-charge-density cationic cellulose ether (KG-30M) ntawm txawv pH qhov tseem ceeb tau kawm nrog ib tug laser scattering instrument, los ntawm lub hydrodynamic vojvoog (Rh) ntawm txawv ces kaum, thiab lub hauv paus txhais tau tias square vojvoog ntawm kev sib hloov. Rg Qhov piv rau Rh infers tias nws cov duab tsis zoo tab sis ze rau spherical. Tom qab ntawd, nrog kev pab los ntawm rheometer, peb cov kev daws teeb meem ntawm cationic cellulose ethers nrog cov nqi sib txawv tau kawm kom ntxaws, thiab kev cuam tshuam ntawm concentration, pH tus nqi thiab nws tus nqi them ceev ntawm nws cov khoom rheological tau tham. Raws li qhov concentration nce, Newton tus exponent thawj zaug txo qis thiab tom qab ntawd txo. Kev hloov pauv lossis txawm tias rov tshwm sim, thiab tus cwj pwm thixotropic tshwm sim ntawm 3% (feem ntau). Tus nqi nruab nrab yog qhov muaj txiaj ntsig kom tau txais ntau dua xoom-shear viscosity, thiab pH tsis tshua muaj txiaj ntsig rau nws cov viscosity.

Cov lus tseem ceeb:cationic cellulose ether; morphology; xoom shear viscosity; rheology

Cellulose derivatives thiab lawv cov kev hloov kho cov khoom siv polymers tau siv dav hauv kev ua haujlwm ntawm lub cev thiab cov khoom huv huv, petrochemicals, tshuaj, khoom noj khoom haus, khoom noj khoom haus, ntim, thiab lwm yam. Dej-soluble cationic cellulose ether (CCE) yog vim nws muaj zog thickening. muaj peev xwm, nws yog dav siv nyob rau hauv cov tshuaj niaj hnub, tshwj xeeb tshaj yog cov tshuaj zawv plaub hau, thiab tuaj yeem txhim kho cov plaub hau tom qab zawv plaub hau. Nyob rau tib lub sijhawm, vim nws qhov zoo sib xws, nws tuaj yeem siv tau hauv cov tshuaj zawv plaub hau hauv ib qho thiab tag nrho-hauv-ib. Nws kuj muaj qhov zoo ntawm daim ntawv thov thiab tau nyiam cov xim ntawm ntau lub teb chaws. Nws tau raug tshaj tawm nyob rau hauv cov ntaub ntawv hais tias cov cellulose derivative daws qhia tus cwj pwm xws li Newtonian kua, pseudoplastic kua, thixotropic kua thiab viscoelastic kua nrog nce concentration, tab sis lub morphology, rheology thiab influencing yam ntawm cationic cellulose ether nyob rau hauv aqueous tov muaj ob peb. tshawb fawb qhia. Daim ntawv no tsom mus rau tus cwj pwm rheological ntawm quaternary ammonium hloov cellulose aqueous tov, txhawm rau muab cov ntaub ntawv siv rau kev siv.

1. Kev sim ib feem

1.1 Cov khoom siv raw

Cationic cellulose ether (KG-30M, JR-30M, LR-30M); Canada Dow Chemical Company cov khoom lag luam, muab los ntawm Procter & Gamble Company Kobe R&D Center hauv Nyij Pooj, ntsuas los ntawm Vario EL elemental analyzer (German Elemental Company), cov qauv Cov ntsiab lus nitrogen yog 2.7%, 1.8%, 1.0% raws li (tus nqi them ceev yog 1.9 Meq / g, 1.25 Meq / g, 0.7 Meq / g raws li), thiab nws raug kuaj los ntawm German ALV-5000E laser teeb Scattering instrument (LLS) ntsuas nws qhov hnyav nruab nrab molecular hnyav yog li 1.64×106 g / mol.

1.2 Kev npaj daws teeb meem

Cov qauv yog purified los ntawm filtration, dialysis thiab freeze-drying. Ntsuas cov qauv ntawm peb qhov ntau npaum li cas, thiab ntxiv cov txheej txheem tsis haum nrog pH 4.00, 6.86, 9.18 txhawm rau npaj qhov xav tau concentration. Txhawm rau kom ntseeg tau tias cov qauv tau yaj tag nrho, tag nrho cov qauv kev daws teeb meem tau muab tso rau ntawm lub tshuab nqus hlau nplaum rau 48 teev ua ntej kev sim.

1.3 Kev ntsuas lub teeb tawg

Siv LLS los ntsuas qhov hnyav-qhov nruab nrab molecular qhov hnyav ntawm tus qauv hauv cov kua dej hauv cov kua dej,, lub vojvoog hydrodynamic thiab lub hauv paus txhais tau tias square vojvoog ntawm kev sib hloov thaum qhov thib ob Villi coefficient thiab cov kaum sib txawv,), thiab infer hais tias qhov no cationic cellulose ether nyob rau hauv. lub aqueous tov los ntawm nws qhov ratio raws li txoj cai.

1.4 Kev ntsuas viscosity thiab kev tshawb nrhiav rheological

Cov tshuaj CCE concentrated tau kawm los ntawm Brookfield RVDV-III + rheometer, thiab kev cuam tshuam ntawm concentration, nqi ceev thiab pH tus nqi ntawm cov khoom rheological xws li cov qauv viscosity tau tshawb xyuas. Thaum siab dua, nws yog ib qho tsim nyog los soj ntsuam nws cov thixotropy.

2. Cov txiaj ntsig thiab kev sib tham

2.1 Kev Tshawb Fawb Txog Lub Teeb Scattering

Vim nws cov qauv molecular tshwj xeeb, nws yog ib qho nyuaj rau muaj nyob rau hauv daim ntawv ntawm ib tug tib molecule txawm nyob rau hauv ib tug zoo hnyav, tab sis nyob rau hauv daim ntawv ntawm tej yam ruaj khov micelles, pawg los yog koom haum.

Thaum cov tshuaj dilute aqueous (~ o.1%) ntawm CCE tau pom nrog lub tshuab ntsuas polarizing, nyob rau hauv keeb kwm yav dhau ntawm cov dub ntoo khaub lig orthogonal teb, "lub hnub qub" ci me ntsis thiab ci ntsa iab tshwm. Nws yog tus yam ntxwv ntxiv los ntawm lub teeb tawg, lub dynamic hydrodynamic radius ntawm pH sib txawv thiab cov ces kaum, lub hauv paus txhais tau tias square vojvoog ntawm kev sib hloov thiab qhov thib ob Villi coefficient tau los ntawm Berry daim duab tau teev nyob rau hauv Tab. 1. Daim duab faib ntawm hydrodynamic vojvoog muaj nuj nqi tau txais ntawm qhov concentration ntawm 10-5 feem ntau yog ib lub ncov, tab sis qhov kev faib tawm yog qhov dav heev (Daim duab 1), qhia tias muaj cov koom haum molecular-theem thiab loj aggregates nyob rau hauv lub system. ; Muaj kev hloov pauv, thiab Rg / Rb qhov tseem ceeb yog nyob ib puag ncig 0.775, qhia tias cov duab ntawm CCE hauv kev daws teeb meem yog nyob ze rau lub kheej kheej, tab sis tsis tu ncua txaus. Cov nyhuv ntawm pH ntawm Rb thiab Rg tsis pom tseeb. Qhov kev tawm tsam hauv qhov kev daws teeb meem tsis sib cuam tshuam nrog CCE los tiv thaiv tus nqi ntawm nws cov hlua sab thiab ua kom nws ntsws, tab sis qhov sib txawv txawv nrog hom kev tawm tsam. Kev ntsuas hluav taws xob tawg ntawm cov khoom siv hluav taws xob muaj qhov cuam tshuam rau kev cuam tshuam ntev ntawm kev quab yuam thiab kev cuam tshuam sab nraud, yog li muaj qee qhov yuam kev thiab kev txwv hauv LLS tus yam ntxwv. Thaum cov feem ntau yog ntau dua 0.02%, feem ntau yog sib cais ob lub ncov lossis ntau lub ncov hauv daim duab Rh faib. Raws li qhov concentration nce, Rh kuj nce ntxiv, qhia tias ntau macromolecules muaj feem cuam tshuam los yog sib sau ua ke. Thaum Cao et al. siv lub teeb tawg los kawm cov copolymer ntawm carboxymethyl cellulose thiab deg-active macromers, kuj tseem muaj qhov sib cais ob lub ncov, ib qho ntawm 30nm thiab 100nm, sawv cev rau kev tsim cov micelles ntawm qib molecular, thiab lwm yam Lub ncov Rh yog kuj. loj, uas yog suav hais tias yog ib qho aggregate, uas zoo ib yam li cov txiaj ntsig tau txiav txim siab hauv daim ntawv no.

2.2 Kev tshawb fawb txog tus cwj pwm rheological

2.2.1 Cov nyhuv ntawm concentration:Ntsuas qhov pom tseeb viscosity ntawm KG-30M cov kev daws teeb meem nrog ntau qhov sib txawv ntawm qhov sib txawv ntawm tus nqi sib txawv, thiab raws li daim ntawv logarithmic ntawm lub hwj chim txoj cai sib npaug uas tau npaj los ntawm Ostwald-Dewaele, thaum qhov loj feem tsis tshaj 0.7%, thiab cov kab ncaj nraim. nrog linear correlation coefficient ntau dua 0.99 tau txais. Thiab raws li qhov concentration nce, tus nqi ntawm Newton tus exponent n txo qis (tag nrho tsawg dua 1), uas qhia pom cov kua dej pseudoplastic. Tsav los ntawm shear quab yuam, macromolecular chains pib untangle thiab orient, yog li cov viscosity txo. Thaum qhov loj feem ntau dua 0.7%, linear correlation coefficient ntawm txoj kab ncaj nraim txo qis (kwv yees 0.98), thiab n pib hloov pauv lossis txawm nce nrog qhov nce siab; thaum qhov loj feem mus txog 3% (Daim duab 2), lub rooj pom tseeb viscosity thawj zaug nce thiab tom qab ntawd txo qis nrog qhov nce ntawm qhov shear rate. Cov xwm txheej no txawv ntawm cov lus ceeb toom ntawm lwm cov kev daws teeb meem anionic thiab cationic polymer. Tus n tus nqi nce, uas yog, cov cuab yeej tsis-Newtonian tsis muaj zog; Newtonian kua yog cov kua nplaum, thiab cov dej tsis sib haum xeeb tshwm sim nyob rau hauv qhov kev txiav txim ntawm kev ntxhov siab, thiab nws tsis tuaj yeem rov qab los; Cov kua dej uas tsis yog-Newtonian muaj qhov rov qab elasticity thiab ib qho tsis tuaj yeem rov qab los. Nyob rau hauv qhov kev txiav txim ntawm kev nyuaj siab shear, lub irreversible plam ntawm molecules tshwm sim, thiab nyob rau tib lub sij hawm, vim hais tias cov macromolecules yog stretched thiab oriented nrog lub shear, ib tug recoverable elastic ib feem yog tsim. Thaum lub zog sab nraud raug tshem tawm, cov macromolecules zoo li rov qab mus rau qhov qub curled daim ntawv, yog li tus nqi ntawm n nce mus. Cov concentration tseem nce ntxiv los tsim cov qauv network. Thaum lub zog shear me me, nws yuav tsis raug rhuav tshem, thiab tsuas yog elastic deformation yuav tshwm sim. Lub sijhawm no, qhov elasticity yuav zoo dua, viscosity yuav tsis muaj zog, thiab tus nqi ntawm n yuav txo; thaum lub sij hawm shear stress yog maj nce thaum lub sij hawm ntsuas, yog li n Tus nqi fluctuates. Thaum cov pawg loj nce mus txog 3%, qhov pom tseeb viscosity thawj zaug nce thiab tom qab ntawd txo qis, vim tias cov shear me me txhawb kev sib tsoo ntawm macromolecules los ua cov aggregates loj, yog li cov viscosity nce, thiab kev nyuaj siab shear tseem ua rau cov aggregates. , lub viscosity yuav txo qis dua.

Nyob rau hauv kev tshawb nrhiav ntawm thixotropy, teem lub ceev (r / min) kom ncav cuag qhov xav tau y, nce qhov ceev ntawm lub sijhawm tsis tu ncua kom txog thaum nws ncav cuag tus nqi, thiab tom qab ntawd sai sai poob ntawm qhov siab tshaj plaws rov qab mus rau qhov pib tus nqi kom tau txais qhov sib thooj. Lub shear kev nyuaj siab, nws txoj kev sib raug zoo nrog tus nqi shear yog qhia nyob rau hauv daim duab 3. Thaum lub loj feem tsawg tshaj li 2.5%, lub upward nkhaus thiab downward nkhaus kiag li sib tshooj, tab sis thaum lub loj feem yog 3%, ob kab tsis muaj. Kev sib tshooj ntev dua, thiab kab nqes nqes rov qab, qhia tias thixotropy.

Lub sij hawm dependence ntawm shear stress yog hu ua rheological tsis kam. Rheological tsis kam yog tus cwj pwm zoo ntawm viscoelastic kua thiab kua nrog cov qauv thixotropic. Nws pom tias qhov loj dua y yog nyob rau tib pawg loj, qhov nrawm dua r mus txog qhov sib npaug, thiab lub sij hawm dependence me dua; ntawm qhov qis qis qis (<2%), CCE tsis qhia txog kev tiv thaiv rheological. Thaum cov feem loj nce mus rau 2.5%, nws qhia tau hais tias lub sij hawm muaj zog dependence (Fig. 4), thiab nws yuav siv sij hawm li 10 feeb mus txog equilibrium, thaum nyob rau ntawm 3.0%, lub sij hawm sib npaug yuav siv sij hawm 50 feeb. Qhov zoo thixotropy ntawm lub cev muaj qhov tsim nyog rau kev siv tswv yim.

2.2.2 Cov txiaj ntsig ntawm kev them nqi ceev:daim ntawv logarithmic ntawm Spencer-Dillon empirical mis yog xaiv, nyob rau hauv uas lub xoom-txiav viscosity, b yog tas li nyob rau tib lub concentration thiab sib txawv kub, thiab nce nrog nce concentration ntawm tib qhov kub thiab txias. Raws li txoj cai lij choj fais fab sib npaug tau txais los ntawm Onogi hauv xyoo 1966, M yog qhov txheeb ze molecular loj ntawm cov polymer, A thiab B yog qhov tsis tu ncua, thiab c yog qhov loj feem (%). Fig.5 Qhov peb nkhaus muaj cov ntsiab lus pom tseeb nyob ib ncig ntawm 0.6%, uas yog, muaj ib qho tseem ceeb ntawm pawg. Ntau tshaj 0.6%, qhov xoom-shear viscosity nce nrawm nrog qhov nce siab C. Cov nkhaus ntawm peb cov qauv nrog cov nqi sib txawv yog ze heev. Hauv qhov sib piv, thaum qhov loj ntawm qhov nruab nrab ntawm 0.2% thiab 0.8%, xoom-txiav viscosity ntawm LR tus qauv nrog tus nqi qis tshaj plaws yog qhov loj tshaj plaws, vim tias lub koom haum hydrogen bond yuav tsum muaj kev sib cuag. Yog li ntawd, tus nqi them ceev yog ze ze rau seb cov macromolecules tuaj yeem npaj tau raws li kev txiav txim siab thiab cog lus; los ntawm kev kuaj DSC, nws pom tias LR muaj qhov tsis muaj zog crystallization ncov, qhia txog qhov tsim nyog tus nqi, thiab xoom-shear viscosity siab dua ntawm tib qhov concentration. Thaum qhov loj feem tsawg dua 0.2%, LR yog qhov tsawg tshaj plaws, vim hais tias hauv cov tshuaj diluted, macromolecules nrog cov nqi qis dua yuav ua rau coil orientation, yog li xoom-shear viscosity tsawg. Qhov no muaj qhov taw qhia qhov tseem ceeb ntawm kev ua haujlwm thickening.

2.2.3 pH nyhuv: Daim duab 6 yog cov txiaj ntsig ntsuas ntawm pH sib txawv hauv thaj tsam ntawm 0.05% mus rau 2.5% pawg pawg. Muaj qhov taw qhia inflection nyob ib ncig ntawm 0.45%, tab sis peb qhov nkhaus yuav luag sib tshooj, qhia tias pH tsis muaj kev cuam tshuam rau xoom-shear viscosity, uas txawv heev ntawm qhov rhiab heev ntawm anionic cellulose ether rau pH.

3. Cov lus xaus

KG-30M dilute aqueous tov yog kawm los ntawm LLS, thiab cov hydrodynamic radius faib tau yog ib qho ncov. Los ntawm lub kaum sab xis dependence thiab Rg / Rb piv, nws muaj peev xwm inferred tias nws cov duab yog ze rau kheej kheej, tab sis tsis tu ncua txaus. Rau cov kev daws teeb meem CCE nrog peb qhov ceev ceev, qhov viscosity nce nrog qhov nce ntawm qhov concentration, tab sis Newton tus lej yos hav zoov n thawj zaug txo qis, ces hloov pauv thiab txawm nce; pH tsis tshua muaj kev cuam tshuam rau lub viscosity, thiab tus nqi qis qis tuaj yeem tau txais viscosity siab dua.