Focus on Cellulose ethers

Yintoni umahluko phakathi kwe-HPMC kunye ne-MC?

A:

I-MC yi-methyl cellulose: icotton esulungekileyo emva konyango lwe-alkali, i-methane chloride njenge-etherifying agent, ngoluhlu lweempendulo ukwenza i-cellulose ether. Ngokuqhelekileyo, iqondo lokutshintshwa yi-1.6 ~ 2.0, kwaye ukunyibilika kuyahluka kunye neqondo lokutshintshwa. Yeye-nonionic cellulose ether.

(1) Ukugcinwa kwamanzi kwi-methyl cellulose kuxhomekeke kwisixa sokongeza, i-viscosity, i-particle fineness kunye neqondo lokuchithwa. Ngokubanzi yongeza isixa esikhulu, i-fineness encinci, i-viscosity, izinga lokugcinwa kwamanzi liphezulu. Isixa sezongezo sinempembelelo enkulu kwisantya sokugcinwa kwamanzi, kwaye i-viscosity ayihambelani nezinga lokugcinwa kwamanzi. Isantya sokuchithwa sixhomekeke ikakhulu kwiqondo lokuguqulwa komphezulu kunye ne-particle fineness yamasuntswana e-cellulose. Kwezi zingentla ze-cellulose ethers, i-methyl cellulose kunye ne-HPMC hydroxypropyl methyl cellulose izinga lokugcinwa kwamanzi liphezulu.

(2) I-Methyl cellulose iyanyibilika emanzini abandayo, okunzima ukuyinyibilika emanzini ashushu. Isisombululo saso samanzi sizinzile kakhulu ngaphakathi kwe-pH = 3 ~ 12. Inokuhambelana kakuhle nestatshi, i-guanidine gum kunye nee-surfactants ezininzi. I-Gelation iyenzeka xa iqondo lokushisa lifikelela kwiqondo lokushisa.

(3) Ukutshintsha kweqondo lobushushu kuyakuchaphazela kakhulu izinga lokugcinwa kwamanzi kwi-methyl cellulose. Ngokuqhelekileyo, okukhona ubushushu buphezulu, kokukhona ukugcinwa kwamanzi kubi. Ukuba ubushushu bodaka bungaphezulu kwe-40℃, ukugcinwa kwamanzi kwi-methyl cellulose kuya kuba kubi kakhulu, okuchaphazela ngokunzulu ukwakhiwa kodaka.

(4) I-Methyl cellulose inefuthe elicacileyo ekwakhiweni kunye nokunamathela kodaka. "Ukunamathela" apha kubhekiselele ekunamatheleni okuvakalelwa ngumsebenzi phakathi kwesixhobo kunye ne-substrate eludongeni, oko kukuthi ukuxhathisa kwe-shear yodaka. Ukubambelela kukhulu, ukuxhathisa kwe-shear yodaka kukhulu, amandla afunwa ngabasebenzi kwinkqubo yokusetyenziswa nawo mkhulu, kwaye ukwakhiwa kodaka kubi. Kwiimveliso ze-cellulose ether, i-adhesion ye-methyl cellulose ikwinqanaba eliphakathi.

I-HPMC yi-hydroxypropyl methyl cellulose: yenziwe ngekotoni esulungekileyo emva konyango lwe-alkali, kunye ne-propylene oxide kunye ne-chloromethane njenge-etherifying agent, ngoluhlu lweempendulo kwaye zenziwe nge-non-ionic cellulose exutywe i-ether. Iqondo lokutshintshwa ngokubanzi yi-1.2 ~ 2.0. Iipropati zayo ziyahluka kunye nomlinganiselo we-methoxy kunye ne-hydroxypropyl content.

(1) I-HPMC i-hydroxypropyl methyl cellulose inyibilika ngokulula emanzini abandayo, ekunzima ukuyinyibilika emanzini ashushu. Nangona kunjalo, ubushushu bayo be-gelation kumanzi ashushu ngokucacileyo bungaphezulu kwe-methyl cellulose. I-solubility ye-methyl cellulose emanzini abandayo nayo yaphuculwa kakhulu.

(2) I-viscosity ye-HPMC i-hydroxypropyl methyl cellulose ihambelana nobunzima bayo be-molecular, kwaye ukuphakama kwe-molecular weight, kuphezulu kwe-viscosity. Ubushushu bukwachaphazela i-viscosity. I-Viscosity iyancipha njengoko ubushushu bukhula. Kodwa i-viscosity yayo ifuthe eliphezulu lobushushu liphantsi kune-methyl cellulose. Isisombululo sizinzile xa sigcinwe kwiqondo lokushisa.

(3) I-HPMC i-hydroxypropyl methyl cellulose izinzile kwi-asidi kunye nesiseko, kwaye isisombululo sayo samanzi sizinzile kakhulu kuluhlu lwe-pH = 2 ~ 12. I-Caustic soda kunye namanzi e-lime anempembelelo encinci kwiipropati zayo, kodwa i-alkali inokukhawulezisa izinga lokuchithwa kwayo kunye nokuphucula i-viscosity. I-HPMC i-hydroxypropyl methyl cellulose izinzile kwiityuwa ngokubanzi, kodwa xa ukuxinwa kwesisombululo setyuwa kuphezulu, i-viscosity ye-HPMC ye-hydroxypropyl methyl cellulose isisombululo ithande ukunyuka.

(4) Ukugcinwa kwamanzi e-HPMC hydroxypropyl methyl cellulose kuxhomekeke kwidosi kunye ne-viscosity, kwaye izinga lokugcinwa kwamanzi e-HPMC hydroxypropyl methyl cellulose liphezulu kunelo le-methyl cellulose kwidosi efanayo.

(5) I-HPMC i-hydroxypropyl methyl cellulose inokuxutywa kunye neekhompawundi zepolymer ezinyibilikayo emanzini ukuze zibe yinto efanayo, isisombululo esiphezulu se-viscosity. Okufana ne-polyvinyl alcohol, i-ether ye-starch, iglue yemifuno kunye nokunye.

(6) Ukunamathela kwe-HPMC i-hydroxypropyl methyl cellulose kulwakhiwo lodaka luphezulu kunolo lwe-methyl cellulose.

(7) I-HPMC i-hydroxypropyl methyl cellulose inokumelana ne-enzyme engcono kune-methyl cellulose, kunye nesisombululo sayo sokutshatyalaliswa kwe-enzyme ye-enzayimu ingaphantsi kune-methyl cellulose.


Ixesha lokuposa: May-26-2022
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