Ethylcellulose yog ib qho derivative ntawm cellulose, lub ntuj polymer tsim los ntawm cov piam thaj units.Nws yog synthesized los ntawm reacting cellulose nrog ethyl chloride los yog ethylene oxide, ua ib feem hloov cellulose molecules.Ethylcellulose muaj ntau yam tshuaj lom neeg uas ua rau nws muaj txiaj ntsig zoo hauv ntau yam kev lag luam thiab kev siv tshuaj.
Molecular Structure:
Ethylcellulose khaws cov qauv hauv paus ntawm cellulose, suav nrog cov piam thaj rov qab txuas ua ke los ntawm β-1,4-glycosidic bonds.
Kev hloov ethyl tshwm sim feem ntau ntawm cov pab pawg hydroxyl ntawm cov pob txha cellulose, ua rau ntau qib kev hloov pauv (DS) qhia qhov nruab nrab ntawm cov ethyl pawg hauv ib chav tsev piam thaj.
Qib ntawm kev hloov pauv cuam tshuam rau cov khoom ntawm ethylcellulose, suav nrog kev solubility, viscosity, thiab muaj peev xwm ua yeeb yaj kiab.
Solubility:
Vim lub hydrophobic xwm ntawm pawg ethyl, ethylcellulose yog insoluble hauv dej.
Nws nthuav tawm solubility nyob rau hauv ntau yam organic solvents, xws li cawv, ketones, esters, thiab chlorinated hydrocarbons.
Solubility nce nrog txo qhov hnyav molecular thiab nce qib ntawm ethoxylation.
Film forming zog:
Ethylcellulose paub txog nws lub peev xwm ua yeeb yaj kiab, ua rau nws muaj txiaj ntsig hauv kev tsim cov txheej txheem, cov yeeb yaj kiab, thiab kev tswj hwm-tso tshuaj formulations.
Lub peev xwm ntawm ethylcellulose yaj nyob rau hauv ntau yam ntawm cov kuab tshuaj organic txhawb kev tsim cov yeeb yaj kiab, nrog rau tom qab evaporation ntawm cov kuab tshuaj tawm hauv cov yeeb yaj kiab.
Reactivity:
Ethylcellulose nthuav tawm qhov tsis tshua muaj tshwm sim nyob rau hauv ib txwm muaj.Txawm li cas los xij, nws tuaj yeem hloov kho los ntawm cov tshuaj tiv thaiv xws li etherification, esterification, thiab cross-linking.
Etherification cov tshuaj tiv thaiv cuam tshuam nrog kev qhia txog kev hloov pauv ntxiv ntawm cov pob txha cellulose, yog li hloov cov khoom.
Esterification tuaj yeem tshwm sim los ntawm reacting ethylcellulose nrog carboxylic acids los yog acid chlorides, ua cellulose esters nrog hloov solubility thiab lwm yam khoom.
Cov kev sib txuas sib txuas tuaj yeem pib los txhim kho lub zog txhua yam thiab thermal stability ntawm ethyl cellulose daim nyias nyias.
Kev ua haujlwm thermal:
Ethylcellulose nthuav tawm thermal stability nyob rau hauv ib tug tej yam kub kub, tshaj qhov uas decomposition tshwm sim.
Thermal degradation feem ntau pib nyob ib ncig ntawm 200-250 ° C, nyob ntawm seb yam xws li kev hloov pauv thiab muaj cov khoom siv yas lossis cov khoom ntxiv.
Thermogravimetric tsom xam (TGA) thiab qhov sib txawv scanning calorimetry (DSC) feem ntau yog siv cov tswv yim los qhia tus cwj pwm thermal ntawm ethylcellulose thiab nws cov khoom sib xyaw.
kev sib raug zoo:
Ethylcellulose yog sib xws nrog ntau yam ntawm lwm cov polymers, plasticizers thiab additives, ua rau nws haum rau kev sib xyaw nrog lwm cov ntaub ntawv kom ua tiav cov khoom xav tau.
Cov additives feem ntau muaj xws li cov yas xws li polyethylene glycol (PEG) thiab triethyl citrate, uas txhim khu kev yooj yim thiab cov khoom ua yeeb yaj kiab.
Kev sib raug zoo nrog cov khoom xyaw tshuaj nquag (APIs) yog qhov tseem ceeb hauv kev tsim cov tshuaj siv tshuaj xws li cov ntsiav tshuaj txuas ntxiv thiab cov tshuaj tiv thaiv kab mob.
Barrier kev ua tau zoo:
Ethylcellulose films muaj cov khoom thaiv zoo heev tiv thaiv ya raws, gases thiab organic vapors.
Cov khoom thaiv no ua rau ethylcellulose haum rau cov ntawv ntim khoom uas tiv thaiv los ntawm ib puag ncig yam tseem ceeb rau kev tswj xyuas cov khoom ncaj ncees thiab txee lub neej.
Rheological zog:
Lub viscosity ntawm cov tshuaj ethylcellulose nyob ntawm seb yam xws li polymer concentration, degree ntawm kev hloov, thiab hnyav hom.
Cov tshuaj ethylcellulose feem ntau pom tus cwj pwm pseudoplastic, txhais tau hais tias lawv cov viscosity txo qis nrog nce shear npaum li cas.
Cov kev tshawb fawb rheological tseem ceeb kom nkag siab txog cov yam ntxwv ntws ntawm cov tshuaj ethylcellulose thaum lub sij hawm ua thiab txheej txheej.
Ethylcellulose yog ntau yam polymer nrog ntau yam tshuaj lom neeg uas ua rau nws muaj txiaj ntsig zoo hauv ntau yam kev lag luam thiab kev siv tshuaj.Nws solubility, film-forming muaj peev xwm, reactivity, thermal stability, compatibility, barrier zog thiab rheology ua rau nws yog ib qho tseem ceeb cov ntaub ntawv rau coatings, films, tswj kev tso tawm formulations thiab ntim cov kev daws teeb meem.Kev tshawb fawb ntxiv thiab kev txhim kho hauv thaj tsam ntawm cellulose derivatives txuas ntxiv nthuav dav cov ntawv thov thiab muaj peev xwm ntawm ethylcellulose hauv ntau qhov chaw.
Post lub sij hawm: Feb-18-2024