Starch ethers thiab cellulose ethers yog ob qho tib si ethers uas ua lub luag haujlwm tseem ceeb hauv ntau yam lag luam, tshwj xeeb tshaj yog hauv kev tsim kho thiab ua cov khoom ntxiv hauv ntau yam khoom. Txawm hais tias lawv muaj qee qhov sib xws, lawv yog cov sib txuas sib txawv nrog cov qauv tshuaj sib txawv, cov khoom siv, thiab kev siv.
1.Chemical qauv:
Starch ether:
Cov hmoov txhuv nplej siab ethers yog muab los ntawm cov hmoov txhuv nplej siab, ib qho polysaccharide tsim los ntawm cov piam thaj. Cov qauv tshuaj ntawm cov hmoov txhuv nplej siab muaj ob yam tseem ceeb: amylose (linear chains ntawm cov piam thaj molecules txuas los ntawm α-1,4-glycosidic bonds) thiab amylopectin (muaj α-1,4 thiab α-1,6- branched polymers nrog glycosidic bonds. ) tiv tauj. Starch ethers tau txais los ntawm kev hloov kho cov pawg hydroxyl ntawm cov hmoov txhuv nplej siab los ntawm cov txheej txheem etherification.
Cellulose ether:
Cellulose, ntawm qhov tod tes, yog lwm polysaccharide, tab sis nws cov qauv muaj cov piam thaj txuas los ntawm β-1,4-glycosidic bonds. Cellulose ethers yog muab los ntawm cellulose los ntawm cov txheej txheem etherification zoo sib xws. Rov ua cov chav nyob hauv cellulose yog txuas los ntawm beta daim ntawv cog lus, tsim cov qauv linear thiab crystalline heev.
2. Qhov chaw:
Starch ether:
Cov hmoov txhuv nplej siab yog los ntawm cov nroj tsuag xws li pob kws, nplej thiab qos yaj ywm. Cov nroj tsuag no yog reservoir ntawm starch thiab starch ethers tuaj yeem muab rho tawm thiab ua tiav.
Cellulose ether:
Cellulose yog lub hauv paus tseem ceeb ntawm cov nroj tsuag cell phab ntsa thiab dav muaj nyob rau hauv cov xwm. Feem ntau qhov chaw ntawm cellulose muaj xws li ntoo pulp, paj rwb, thiab ntau yam nroj tsuag fibers. Cellulose ethers yog tsim los ntawm kev hloov kho cellulose molecules muab rho tawm los ntawm cov peev txheej no.
3. Etherification txheej txheem:
Starch ether:
Cov txheej txheem etherification ntawm cov hmoov txhuv nplej siab suav nrog kev qhia cov ether pawg rau hauv pawg hydroxyl (OH) uas muaj nyob hauv cov hmoov txhuv nplej siab. Feem ntau ether pawg ntxiv muaj xws li methyl, ethyl, hydroxyethyl, thiab hydroxypropyl, uas ua rau muaj kev hloov pauv hauv cov khoom ntawm cov hmoov txhuv nplej siab hloov.
Cellulose ether:
Etherification ntawm cellulose koom nrog cov txheej txheem zoo sib xws uas ether pawg tau nkag mus rau hauv pawg hydroxyl ntawm cellulose. Feem ntau cov cellulose ether derivatives muaj xws li methylcellulose, ethylcellulose, hydroxyethylcellulose thiab carboxymethylcellulose.
4. Solubility:
Starch ether:
Starch ethers feem ntau muaj cov dej solubility qis dua cellulose ethers. Nyob ntawm cov pab pawg ether tshwj xeeb txuas nrog thaum hloov kho, lawv tuaj yeem pom qhov sib txawv ntawm kev solubility.
Cellulose ether:
Cellulose ethers paub txog lawv cov dej-soluble lossis dej-dispersible zog. Solubility nyob ntawm hom thiab qib ntawm ether hloov.
5. Film-forming kev ua tau zoo:
Starch ether:
Cov hmoov txhuv nplej siab ethers feem ntau muaj peev xwm tsim cov yeeb yaj kiab vim lawv qhov xwm txheej semi-crystalline. Cov yeeb yaj kiab uas tau tshwm sim tuaj yeem tsis muaj pob tshab thiab tsis yooj yim dua li cov yeeb yaj kiab ua los ntawm cellulose ethers.
Cellulose ether:
Cellulose ethers, tshwj xeeb tshaj yog cov derivatives xws li methylcellulose, paub txog lawv cov yeeb yaj kiab zoo heev. Lawv tuaj yeem tsim cov yeeb yaj kiab meej thiab hloov tau yooj yim, ua rau lawv muaj txiaj ntsig zoo hauv cov ntawv thov xws li txheej txheej thiab cov nplaum.
6.Rheological zog:
Starch ether:
Cov hmoov txhuv nplej siab tuaj yeem ua rau kom cov viscosity ntawm cov tshuaj aqueous, tab sis lawv cov cwj pwm rheological yuav txawv ntawm cellulose ethers. Cov nyhuv ntawm viscosity nyob ntawm seb yam xws li kev hloov pauv thiab qhov hnyav molecular.
Cellulose ether:
Cellulose ethers tau dav lees paub rau lawv cov peev xwm tswj hwm rheology. Lawv tuaj yeem cuam tshuam rau viscosity, dej tuav thiab ntws cov khoom hauv ntau yam kev siv nrog rau cov xim, cov nplaum thiab cov khoom siv.
7. Daim ntawv thov:
Starch ether:
Starch ethers tuaj yeem siv rau hauv cov khoom noj, textile thiab tshuaj lag luam. Hauv kev tsim kho kev lag luam, lawv tau siv hauv mortars, plasters thiab adhesives los txhim kho cov khoom xws li dej tuav thiab ua haujlwm.
Cellulose ether:
Cellulose ethers yog siv dav hauv kev lag luam, khoom noj, tshuaj pleev ib ce thiab kev tsim kho. Lawv tau dav siv los ua thickeners, stabilizers thiab rheology modifiers hauv cov xim, mortars, pobzeb adhesives thiab ntau yam formulations.
8. Biodegradability:
Starch ether:
Starch ethers yog muab los ntawm cov nroj tsuag thiab feem ntau biodegradable. Lawv pab kom muaj kev ruaj ntseg ntawm cov khoom siv.
Cellulose ether:
Cellulose ethers muab tau los ntawm cov nroj tsuag cellulose kuj biodegradable. Lawv cov kev sib raug zoo ib puag ncig yog qhov txiaj ntsig tseem ceeb hauv cov ntawv thov uas kev ruaj ntseg yog qhov tseem ceeb.
nyob rau hauv xaus:
Txawm hais tias cov hmoov txhuv nplej siab ethers thiab cellulose ethers sib koom qee qhov sib xws li polysaccharide derivatives, lawv cov qauv tshuaj tshwj xeeb, qhov chaw, solubility, zaj duab xis-tsim cov khoom, rheological cwj pwm thiab daim ntaub ntawv muab lawv sib nrug rau siv nyob rau hauv ntau yam teb. Cov hmoov txhuv nplej siab ethers tau los ntawm cov hmoov txhuv nplej siab thiab cellulose ethers tau los ntawm cellulose txhua tus muaj qhov zoo sib xws hauv ntau qhov xwm txheej. Kev nkag siab txog qhov sib txawv no yog qhov tseem ceeb rau kev xaiv txoj cai ether rau ib daim ntawv thov tshwj xeeb, kom ntseeg tau tias kev ua tau zoo thiab cov yam ntxwv xav tau.
Post lub sij hawm: Jan-25-2024