Cov nyhuv thickening ntawmcellulose ethernyob ntawm: degree ntawm polymerization ntawm cellulose ether, kua concentration, shear npaum li cas, kub thiab lwm yam mob. Cov cuab yeej gelling ntawm cov tshuaj yog tshwj xeeb rau alkyl cellulose thiab nws cov derivatives hloov. Cov khoom gelation muaj feem xyuam rau qib ntawm kev hloov pauv, tshuaj concentration thiab additives. Rau hydroxyalkyl hloov derivatives, cov khoom gel kuj muaj feem xyuam nrog kev hloov kho qib ntawm hydroxyalkyl. Rau qis viscosity MC thiab HPMC, 10% -15% tov tuaj yeem npaj, nruab nrab viscosity MC thiab HPMC tuaj yeem npaj 5%-10% tov, thiab siab viscosity MC thiab HPMC tsuas tuaj yeem npaj 2%-3% tov, thiab feem ntau Kev faib tawm viscosity ntawm cellulose ether kuj tau muab qhab nia nrog 1% -2% tov.
High-molecular-yuag cellulose ether muaj cov thickening efficiency, thiab polymers nrog txawv molecular luj muaj sib txawv viscosities nyob rau hauv tib concentration tov. Lub hom phiaj viscosity tsuas tuaj yeem ua tiav los ntawm kev ntxiv ib qho loj ntawm qhov hnyav molecular cellulose ether. Nws viscosity muaj me ntsis nyob ntawm tus nqi shear, thiab lub siab viscosity ncav cuag lub hom phiaj viscosity, yuav tsum tau ntxiv tsawg dua, thiab viscosity nyob ntawm qhov thickening efficiency. Yog li ntawd, kom ua tiav ib qho kev sib xws, qee qhov ntawm cellulose ether (kev sib xyaw ntawm cov tshuaj) thiab cov tshuaj viscosity yuav tsum tau lav. Cov gel kub ntawm cov tshuaj kuj txo qis linearly nrog qhov nce ntawm cov concentration ntawm cov tshuaj, thiab gels ntawm chav tsev kub tom qab ncav cuag ib tug tej yam concentration. Lub gelling concentration ntawm HPMC yog qhov siab ntawm chav tsev kub.
Kev sib raug zoo kuj tuaj yeem hloov kho los ntawm kev xaiv qhov loj me thiab xaiv cellulose ethers nrog ntau qib kev hloov kho. Qhov kev hloov pauv yog los qhia txog qee qhov kev hloov pauv ntawm pawg hydroxyalkyl ntawm cov pob txha pob txha ntawm MC. Los ntawm kev hloov pauv tus txheeb ze qhov txiaj ntsig ntawm ob tus neeg hloov pauv, uas yog, DS thiab MS txheeb ze hloov pauv qhov txiaj ntsig ntawm pawg methoxy thiab hydroxyalkyl uas peb feem ntau hais. Ntau yam kev ua tau zoo ntawm cellulose ether tuaj yeem tau txais los ntawm kev hloov pauv cov txiaj ntsig sib txawv ntawm ob qhov hloov pauv.
High-viscosity cellulose ether aqueous tov muaj thixotropy siab, uas kuj yog ib qho tseem ceeb ntawm cellulose ether. Aqueous kev daws teeb meem ntawm MC polymers feem ntau muaj pseudoplastic thiab non-thixotropic fluidity hauv qab lawv cov gel kub, tab sis Newtonian ndlwg zog ntawm qis shear tus nqi. Pseudoplasticity nce nrog qhov hnyav molecular lossis concentration ntawm cellulose ether, tsis hais hom kev hloov pauv thiab qib ntawm kev hloov pauv. Yog li ntawd, cellulose ethers ntawm tib qib viscosity, tsis hais MC, HPMC, HEMC, yuav ib txwm qhia tib yam rheological zog ntev npaum li qhov concentration thiab kub nyob twj ywm. Cov txheej txheem gels yog tsim thaum qhov kub thiab txias, thiab thixotropic ntws heev. High concentration thiab tsawg viscosity cellulose ethers qhia thixotropy txawm nyob rau hauv lub gel kub. Cov cuab yeej no muaj txiaj ntsig zoo rau kev hloov kho ntawm qib thiab sagging hauv kev tsim kho ntawm lub tsev mortar.
Nws yuav tsum tau piav qhia ntawm no tias qhov siab dua qhov viscosity ntawmcellulose ether, qhov zoo dua cov dej tuav, tab sis qhov siab dua qhov viscosity, qhov siab dua qhov sib txheeb molecular hnyav ntawm cellulose ether, thiab qhov sib thooj hauv nws cov solubility, uas muaj kev cuam tshuam tsis zoo rau cov mortar concentration thiab kev tsim kho. Qhov siab dua qhov viscosity, qhov pom tseeb dua cov nyhuv thickening ntawm cov tshuaj khib, tab sis nws tsis yog proportional kiag li. Qee qhov nruab nrab thiab qis viscosity, tab sis hloov kho cellulose ether muaj kev ua tau zoo dua hauv kev txhim kho lub zog ntawm cov mortar ntub dej. Nrog rau qhov nce ntawm viscosity, cov dej tuav ntawm cellulose ether txhim kho.
Lub sij hawm xa tuaj: Plaub Hlis-28-2024