Waterborne coatings tau dhau los ua qhov tseem ceeb hauv kev lag luam niaj hnub txheej txheej vim lawv cov khoom zoo ib puag ncig thiab tsis tshua muaj hluav taws xob organic compound (VOC) emissions. Txawm li cas los xij, piv nrog cov txheej txheem hnyav-raws li cov txheej txheem, cov txheej txheem dej feem ntau ntsib teeb meem ntawm kev ua yeeb yaj kiab thiab kev ua kom zoo. Txhawm rau daws cov teeb meem no, qee qhov kev ua haujlwm ntxiv feem ntau yog ntxiv rau cov qauv. Hydroxyethyl cellulose (HEC) yog ib qho ntawm cov thickeners siv dav thiab cov khoom siv ntxiv, uas ua lub luag haujlwm tseem ceeb hauv kev txhim kho cov yeeb yaj kiab tsim thiab adhesion ntawm cov txheej txheem dej.
1. Cov khoom tseem ceeb ntawm hydroxyethyl cellulose (HEC)
HEC yog cov dej-soluble polymer uas tsis yog-ionic uas tau txais los ntawm kev hloov kho tshuaj ntawm natural cellulose. Nws cov qauv molecular muaj ntau pawg hydroxyethyl, uas ua rau nws muaj cov dej solubility zoo thiab cov khoom ua yeeb yaj kiab. Cov yam ntxwv tseem ceeb ntawm HEC suav nrog:
Cov nyhuv Thickening: HEC tuaj yeem ua kom cov viscosity ntawm cov txheej txheem dej, ua rau lawv zoo dua rheology thiab ruaj khov thaum txheej txheej.
Cov cuab yeej ua yeeb yaj kiab: HEC tuaj yeem tsim cov yeeb yaj kiab tsis sib xws thaum lub sijhawm ziab ntawm txheej txheej, txhim kho lub cev lub cev ntawm txheej.
Compatibility: HEC muaj kev sib raug zoo nrog ntau yam dej-raws li resins thiab pigments, thiab nws tsis yooj yim rau formula instability los yog stratification.
2. Mechanism ntawm HEC hauv kev txhim kho zaj duab xis-tsim cov khoom hauv dej-raws li txheej txheej
HEC tuaj yeem txhim kho cov yeeb yaj kiab tsim cov khoom hauv cov txheej txheem dej, feem ntau yog vim nws cov qauv molecular tshwj xeeb thiab lub cev thiab tshuaj lom neeg.
Lub cev cross-linking ntawm molecular chains: HEC molecular chains ntev thiab hloov tau. Thaum lub sij hawm ziab ntawm txheej txheej, cov saw hlau molecular no tuaj yeem cuam tshuam nrog ib leeg los ua ib qho kev sib txuas ntawm lub cev sib txuas, ua kom lub zog thiab ua kom yooj yim ntawm cov txheej.
Kev tswj cov dej noo: HEC muaj cov dej tuav tau zoo thiab tuaj yeem maj mam tso cov dej noo thaum lub sij hawm ziab ntawm txheej txheej, ua kom lub sij hawm ua zaj duab xis, ua rau cov txheej txheem tsim kom sib npaug, thiab txo qhov tawg thiab shrinkage los ntawm kev ziab sai heev.
Kev tswj qhov nro: HEC tuaj yeem txo qhov nro ntawm cov dej-raws li txheej txheej, txhawb kev ntub dej thiab sib kis ntawm cov txheej txheem ntawm cov txheej txheej, thiab txhim kho cov txheej txheem sib xws thiab flatness ntawm txheej.
3. Mechanism ntawm HEC hauv kev txhim kho adhesion hauv dej-raws li txheej txheej
HEC kuj tseem tuaj yeem txhim kho qhov adhesion ntawm cov dej-raws li txheej txheej, uas yog qhov tseem ceeb hauv cov hauv qab no:
Kev txhim kho kev sib txuas: Kev faib tawm tsis sib xws ntawm HEC hauv txheej txheej tuaj yeem ua rau thaj chaw sib cuag ntawm cov txheej thiab substrate nto thiab txhim kho lub zog sib cuam tshuam. Nws cov saw molecular tuaj yeem cuam tshuam nrog me me concave thiab convex qhov chaw ntawm lub substrate nto los txhim kho lub cev adhesion.
Chemical compatibility: HEC yog non-ionic polymer nrog cov tshuaj zoo sib xws nrog ntau hom substrates (xws li hlau, ntoo, yas, thiab lwm yam), thiab tsis yooj yim los ua tshuaj lom neeg lossis teeb meem kev sib raug zoo, yog li txhim kho adhesion.
Plasticizing nyhuv: HEC tuaj yeem ua lub luag haujlwm ntawm plasticizing hauv cov txheej txheem ziab ntawm txheej txheej, ua rau cov txheej txheem hloov tau yooj yim, yog li nws tuaj yeem hloov kho kom zoo dua rau qhov me me deformation thiab thermal expansion thiab contraction ntawm substrate nto, thiab txo cov tev thiab tawg. ntawm txheej.
4. Daim ntawv thov piv txwv thiab cov teebmeem ntawm HEC
Nyob rau hauv kev siv tswv yim, HEC yog dav siv nyob rau hauv ntau hom dej-raws li txheej formulations, xws li dej-raws li architectural txheej, dej-raws li ntoo txheej, dej-raws li industrial coatings, thiab lwm yam. Los ntawm kev ntxiv ib tug tsim nyog tus nqi ntawm HEC, kev tsim kho kev ua tau zoo ntawm cov txheej thiab qhov zoo ntawm cov zaj duab xis zaum kawg tuaj yeem txhim kho tau zoo.
Water-based architectural coatings: Nyob rau hauv dej-raws li phab ntsa xim thiab sab nrauv phab ntsa xim, ntxiv HEC tuaj yeem txhim kho cov txheej txheej dov thiab txhuam kev ua haujlwm, ua rau cov txheej txheem yooj yim dua thiab cov txheej txheem ntau dua thiab du. Nyob rau tib lub sijhawm, HEC cov dej tuav kuj tuaj yeem tiv thaiv cov kab nrib pleb hauv cov yeeb yaj kiab txheej los ntawm kev ziab sai heev.
Dej-raws li cov xim ntoo: Hauv dej-raws li cov xim ntoo, HEC lub thickening thiab film-forming zog pab txhim kho cov pob tshab thiab flatness ntawm cov xim zaj duab xis, ua rau cov ntoo saum npoo zoo nkauj thiab ntuj. Tsis tas li ntawd, HEC tuaj yeem txhim kho cov dej tsis kam thiab tshuaj lom neeg ntawm cov yeeb yaj kiab txheej thiab txhim kho kev tiv thaiv ntawm ntoo.
Dej-raws li kev lag luam coatings: Hauv dej-raws li cov hlau coatings thiab anti-corrosion coatings, HEC's adhesion enhancement tso cai rau cov txheej txheem ua kom zoo dua rau cov hlau nto, txhim kho kev tiv thaiv corrosion thiab kev pab cuam lub neej.
Raws li ib qho tseem ceeb ua hauj lwm additive, hydroxyethyl cellulose (HEC) ho txhim kho lub zuag qhia tag nrho kev ua tau zoo ntawm txheej nyob rau hauv dej-raws li coatings los ntawm kev txhim kho cov zaj duab xis-forming zog thiab adhesion. Nws thickening, dej tuav, zaj duab xis-tsim thiab cuam tshuam kev cuam tshuam ua rau cov dej-raws li txheej txheem ua tau zoo nyob rau hauv ntau yam kev thov scenarios, yog li ua tau raws li kev lag luam xav tau rau kev ua haujlwm siab, ib puag ncig tus phooj ywg txheej. Nyob rau hauv lub neej yav tom ntej, nrog kev txhim kho txuas ntxiv ntawm kev tiv thaiv ib puag ncig thiab kev ua tau zoo, daim ntawv thov kev cia siab ntawm HEC hauv cov txheej txheem dej yuav dav dua.
Post lub sij hawm: Lub Xya hli ntuj-12-2024