Xim thiab txheej yog cov ntaub ntawv tseem ceeb hauv kev lag luam niaj hnub thiab kev tsim kho, thiab lawv tau siv dav los tiv thaiv thiab ua kom zoo nkauj. Txawm li cas los xij, txhawm rau kom ntseeg tau tias cov ntaub ntawv no muaj kev tsim kho zoo, kev tiv thaiv ib puag ncig thiab kev ua haujlwm ruaj khov nyob rau hauv ib puag ncig kev tsim kho sib txawv, kev tswj hwm ntawm cov khoom rheological yog qhov tseem ceeb tshwj xeeb. Hydroxypropyl Methyl Cellulose (HPMC), raws li ib qho kev siv dej-soluble polymer compound, plays lub luag haujlwm tseem ceeb hauv kev txhim kho rheological zog ntawm cov xim thiab coatings.
Cov yam ntxwv tseem ceeb ntawm HPMC
HPMC yog lub ntuj tsim cellulose derivative, uas yog npaj los ntawm kev hloov qee pawg hydroxyl hauv cellulose molecules nrog methoxy thiab hydroxypropoxy pawg. Cov yam ntxwv ntawm HPMC ua rau nws muaj qhov zoo solubility hauv dej thiab tsim pob tshab los yog translucent colloidal daws. Tsis tas li ntawd, nws muaj zog viscosity tswj cov nyhuv, zoo dej tuav thiab tsim ib tug niaj hnub zaj duab xis, uas ua rau nws ib tug ntawm cov zoo tagnrho additives nyob rau hauv cov xim thiab txheej kev lag luam.
Mechanism ntawm kev ua ntawm HPMC nyob rau hauv cov xim thiab coatings
Kev tswj cov khoom rheological Rheological zog xa mus rau qhov deformation thiab ntws tus cwj pwm ntawm cov ntaub ntawv nyob rau hauv sab nraud rog. Rau cov xim thiab coatings, cov khoom zoo rheological pab txhim kho lawv cov kev tsim kho thiab tsis txhob muaj teeb meem xws li sagging thiab splashing. HPMC muaj cov nyhuv thickening nyob rau hauv dej-raws li systems. Nws tsub kom lub viscosity ntawm txheej los ntawm kev tsim ib tug network qauv, yog li txhim kho lub anti-sagging kev ua tau zoo ntawm txheej thaum lub sij hawm tsim kho, thiaj li hais tias nws muaj peev xwm yuav sib npaug zos rau ntawm ntsug nto yam tsis muaj ntau txaus txaus.
Tshwj xeeb, cov macromolecular chains ntawm HPMC tsim ib lub network qauv hauv kev daws teeb meem, uas tuaj yeem ua rau kom cov viscosity ntawm lub kaw lus qis qis thiab qhia shear thinning cov yam ntxwv ntawm cov nqi siab. Qhov no txhais tau hais tias thaum txhuam los yog txau, cov viscosity ntawm cov xim yuav txo qis vim yog sab nraud quab yuam, ua rau cov txhuam hniav smoother, thiab tom qab lub zog sab nraud nres, cov viscosity yuav rov qab sai los tiv thaiv cov txheej los ntawm ntws thiab sagging. Cov cuab yeej shear thinning no zoo heev txhim kho kev tsim kho ntawm cov xim thiab coatings.
Kev tuav dej thiab kev ruaj ntseg HPMC kuj muaj cov dej tuav ruaj khov, uas tuaj yeem txuas ntxiv lub sijhawm ziab ntawm cov xim thiab cov txheej txheem, kom ntseeg tau tias cov txheej yuav tsis tawg vim dej ntau dhau thaum lub sijhawm ziab. Cov cuab yeej no tseem ceeb tshwj xeeb hauv qhov chaw kub thiab qhuav kev tsim kho vim tias nws tiv thaiv cov dej hauv cov xim los ntawm evaporating ntxov ntxov, ua kom cov txheej txheej dries tusyees, thiab yog li txhim kho cov adhesion thiab smoothness ntawm cov xim.
HPMC tuaj yeem txhim kho qhov ruaj khov ntawm cov xim. Vim nws cov nyhuv thickening, nws muaj peev xwm tiv thaiv cov xim los ntawm stratifying thiab nyob rau hauv lub sij hawm ntev cia, tuav lub uniformity ntawm lub system, thiab ncua lub txee lub neej ntawm cov xim.
Txhim kho pigment dispersion Hauv cov xim pleev xim, cov xim yog cov khoom tseem ceeb uas txiav txim siab xim thiab kev pab them nqi. Txhawm rau kom ntseeg tau cov xim sib xws thiab kev tiv thaiv siab ntawm cov xim, cov xim yuav tsum sib npaug sib npaug hauv qhov system. Qhov sib ntxiv ntawm HPMC tuaj yeem txhim kho qhov tawg ntawm cov xim, kom cov xim pigment nyob twj ywm hauv lub xeev zoo raug tshem tawm hauv cov xim pleev xim, tiv thaiv cov khoom los ntawm kev daws teeb meem, thiab xyuas kom meej qhov sib xws ntawm cov xim txheej. Tsis tas li ntawd, qhov ntub dej ntawm HPMC ua rau nws txo qis cov agglomeration ntawm cov xim pigment thiab txhim kho lub zog xim thiab gloss ntawm cov xim.
Tiv thaiv kom tsis txhob txaws thiab txhuam cov cim Thaum lub sij hawm kev tsim kho, tshwj xeeb tshaj yog los ntawm kev txau thiab txhuam, cov xim thiab cov txheej txheem feem ntau ntsib teeb meem ntawm kev txaws thiab txhuam cov cim. Splashing tsis tsuas yog cov khoom siv khib nyiab, tab sis kuj tuaj yeem ua paug rau qhov chaw tsim kho, thaum txhuam cov cim cuam tshuam rau qhov smoothness thiab zoo nkauj ntawm txheej txheej kawg. HPMC tuaj yeem txo qhov txaws ntawm cov xim thaum tsim kho los ntawm kev kho cov viscosity thiab fluidity ntawm cov xim, thiab tib lub sijhawm ua rau cov xim zoo nkauj ntawm qhov chaw thiab txo cov cim ntawm txhuam.
Kev cuam tshuam rau txheej txheej txheej txheej txheej txheej txheej txheej txheem cuam tshuam los ntawm cov khoom rheological thiab ziab txheej txheem ntawm cov xim. Vim nws cov yeeb yaj kiab zoo-tsim thiab dej khaws cia, txhim kho cov xim ua kom zoo dua qub, txhim kho cov txheej txheem ua kom qhuav thiab huab cua tsis kam ntawm cov txheej. Nyob rau tib lub sijhawm, nws tseem tuaj yeem txhim kho qhov adhesion ntawm txheej txheej, kom cov txheej txheej muaj cov khoom sib txuas zoo dua ntawm qhov sib txawv ntawm cov substrates thiab ua kom lub neej ntev ntawm cov txheej txheem.
Kev siv HPMC hauv ntau hom txheej txheej
HPMC tuaj yeem siv dav hauv ntau hom txheej txheej xws li cov xim dej, cov xim pleev xim, thiab cov xim vaj tsev. Rau cov xim pleev xim dej, HPMC tuaj yeem txhim kho nws cov viscosity, theem thiab kev tsim kho; Nyob rau hauv cov xim latex, HPMC lub thickening thiab dej tuav cov khoom yog tshwj xeeb tshaj yog tseem ceeb, txhim khu kev tsim efficiency thiab txheej zoo ntawm cov xim. Nyob rau hauv lub tshav pob ntawm architectural coatings, HPMC txhim kho cov anti-sagging thiab anti-splashing zog ntawm cov xim los ntawm kev kho cov rheological zog ntawm cov xim, adapting rau cov kev xav tau ntawm loj-chaw tsim kho.
HPMC, raws li cov thickener zoo thiab rheology hloov kho, plays lub luag haujlwm tseem ceeb hauv cov xim thiab txheej. Nws tuaj yeem tsis tsuas yog txhim kho cov khoom rheological ntawm cov txheej txheem, xyuas kom meej qhov sib xws thiab kev ua haujlwm ntawm cov txheej thaum tsim kho, tab sis kuj tseem txhim kho qhov kawg ntawm txheej txheej thiab txuas ntxiv kev khaws cia thiab kev pabcuam lub neej ntawm txheej txheej. Nrog rau kev txhim kho txuas ntxiv ntawm kev lag luam niaj hnub txheej txheej, daim ntawv thov ntawm HPMC yuav dhau los ua qhov dav thiab dhau los ua ib qho tseem ceeb los txhawb kev ua haujlwm ntawm cov txheej txheem.
Post lub sij hawm: Sep-29-2024