Cellulose yog polysaccharide uas tsim ntau yam dej-soluble ethers. Cellulose thickeners yog nonionic dej-soluble polymers. Nws siv keeb kwm ntev heev, ntau tshaj 30 xyoo, thiab muaj ntau ntau yam. Lawv tseem siv nyob rau hauv yuav luag tag nrho cov xim latex thiab yog lub ntsiab ntawm thickeners. Cellulosic thickeners zoo heev nyob rau hauv aqueous systems vim lawv thicken cov dej lawv tus kheej. Hauv kev lag luam xim, feem ntau siv cellulose thickeners yog: methyl cellulose (MC), hydroxyethyl cellulose (HEC), ethyl hydroxyethyl cellulose (EHEC), hydroxypropyl cellulose (HPC), hydroxypropyl methyl cellulose (HPMC) thiab hydrophobically hloov hydroxyethyl cellulose ( HMO). HEC yog cov dej-soluble polysaccharide dav siv nyob rau hauv cov thickening ntawm matt thiab semi-gloss architectural latex xim. Thickeners muaj nyob rau hauv ntau qib viscosity thiab thickeners nrog cov cellulose no muaj cov xim zoo sib xws thiab khaws cia ruaj khov.
Lub leveling, anti-splash, film-forming thiab anti-sagging zog ntawm txheej zaj duab xis nyob ntawm seb tus txheeb ze molecular hnyav ntawm HEC. HEC thiab lwm yam dej-soluble polymers uas tsis yog-soluble polymers thicken lub aqueous theem ntawm txheej. Cellulose thickeners tuaj yeem siv ib leeg lossis ua ke nrog lwm cov thickeners kom tau txais cov lus qhia tshwj xeeb. Cellulose ethers tuaj yeem muaj qhov sib txawv ntawm qhov sib txawv molecular hnyav thiab cov qib viscosity sib txawv, xws li qhov hnyav molecular 2% aqueous tov nrog viscosity ntawm 10 MPS mus rau cov txheeb ze molecular hnyav viscosity ntawm 100 000 MPS. Cov qib qis molecular hnyav feem ntau yog siv los tiv thaiv colloids hauv latex xim emulsion polymerization, thiab feem ntau cov qib (viscosity 4 800-50 000 MP·S) yog siv los ua thickeners. Lub tshuab ntawm hom thickener no yog vim lub siab hydration ntawm hydrogen bonds thiab entanglement ntawm nws molecular chains.
Traditional cellulose yog ib tug siab molecular hnyav polymer uas thickens mas los ntawm cov entanglement ntawm molecular chains. Vim lub siab viscosity ntawm qis shear tus nqi, cov cuab yeej leveling tsis zoo, thiab nws cuam tshuam rau lub gloss ntawm txheej zaj duab xis. Thaum lub siab shear npaum li cas, lub viscosity yog tsawg, lub splash tsis kam ntawm txheej zaj duab xis yog tsis zoo, thiab tag nrho ntawm cov txheej zaj duab xis yog tsis zoo. Daim ntawv thov cov yam ntxwv ntawm HEC, xws li txhuam tsis kam, kev ua yeeb yaj kiab thiab cov menyuam spatter, yog ncaj qha cuam tshuam rau kev xaiv cov thickener. Tsis tas li ntawd nws cov khoom ntws xws li qib thiab sag kuj cuam tshuam loj heev los ntawm thickeners.
Hydrophobically modified cellulose (HMHEC) yog ib qho cellulose thickener uas muaj hydrophobic hloov kho ntawm ib co ceg chains (ntau cov saw ntev alkyl pawg yog qhia raws cov saw tseem ceeb ntawm cov qauv). Cov txheej no muaj viscosity ntau dua ntawm cov shear siab thiab yog li tsim cov yeeb yaj kiab zoo dua. Xws li Natrosol Plus Qib 330, 331, Cellosize SG-100, Bermocoll EHM-100. Nws cov nyhuv thickening yog piv rau cov cellulose ether thickeners nrog ntau cov txheeb ze molecular loj. Nws txhim kho cov viscosity thiab qib ntawm ICI, thiab txo qhov nro ntawm qhov chaw. Piv txwv li, qhov nro ntawm HEC yog li 67 MN / m, thiab qhov nro ntawm HMHEC yog 55 ~ 65 MN / m.
HMHEC muaj zoo heev sprayability, anti-sagging, leveling zog, zoo gloss thiab anti-pigment caking. Nws yog dav siv thiab tsis muaj qhov tsis zoo rau kev tsim cov yeeb yaj kiab ntawm cov xim loj me me latex. Zoo zaj duab xis-tsim kev ua tau zoo thiab anti-corrosion kev ua tau zoo. Qhov tshwj xeeb associative thickener no ua haujlwm zoo dua nrog vinyl acetate copolymer systems, thiab nws qhov kev ua tau zoo zoo ib yam li lwm cov thickeners associative, tab sis nrog cov qauv yooj yim.
Post lub sij hawm: Mar-16-2023