Intshayelelo yee-ethers ezininzi eziqhelekileyo ze-cellulose

I-Methylcellulose (MC)

Ifomula yemolekyuli ye-methylcellulose (MC) yile:

[C6H7O2(OH)3-h(OCH3)n\]x

Inkqubo yokuvelisa kukwenza i-cellulose ether ngokusebenzisa uluhlu lweempendulo emva kokuba umqhaphu ococekileyo uphathwe nge-alkali, kwaye i-methyl chloride isetyenziswe njenge-etherification agent. Ngokubanzi, iqondo lokutshintsha liyi-1.6 ~ 2.0, kwaye ukunyibilika kwahluka ngokwamanqanaba okutshintsha. yeye-non-ionic cellulose ether.

I-Methylcellulose i-soluble emanzini abandayo, kwaye kuya kuba nzima ukuyichitha emanzini ashushu. Isisombululo saso samanzi sizinzile kakhulu kuluhlu lwe-pH = 3 ~ 12.

Inokuhambelana kakuhle nestatshi, i-guar gum, njl. kunye nee-surfactants ezininzi. Xa iqondo lokushisa lifikelela kwiqondo lokushisa, i-gelation iyenzeka.

Ukugcinwa kwamanzi kwe-methylcellulose kuxhomekeke kwisixa sokongeza, i-viscosity, i-particle fineness kunye nesantya sokuchithwa.

Ngokuqhelekileyo, ukuba isixa esongezelelweyo sikhulu, i-fineness incinci, kwaye i-viscosity inkulu, izinga lokugcinwa kwamanzi liphezulu. Phakathi kwabo, inani lokongezelela linempembelelo enkulu kwizinga lokugcinwa kwamanzi, kwaye inqanaba le-viscosity alilingani ngokuthe ngqo kwinqanaba lokugcinwa kwamanzi. Izinga lokuchithwa ikakhulu lixhomekeke kwiqondo lokuguqulwa komphezulu wamasuntswana e-cellulose kunye ne-particle fineness.

Phakathi kwezi ether ze-cellulose ezingentla, i-methyl cellulose kunye ne-hydroxypropyl methyl cellulose zinezinga eliphezulu lokugcina amanzi.

I-Carboxymethylcellulose (CMC)

I-Carboxymethyl cellulose, eyaziwa ngokuba yi-sodium carboxymethyl cellulose, eyaziwa ngokuba yi-cellulose, i-cmc, njl. Imichiza ekrwada.

Isetyenziswa ikakhulu kumashishini okucoca, ishishini lokutya kunye nolwelo lokomba lweoli kwintsimi, kwaye isixa esisetyenziswa kwizinto zokuthambisa kuphela malunga ne-1%.

I-Ionic cellulose ether yenziwe kwimicu yendalo (ikotoni, njl.njl.) emva konyango lwe-alkali, kusetyenziswa i-sodium monochloroacetate njenge-etherification agent, kwaye iphantsi koluhlu lwezonyango zokusabela.

Iqondo lokutshintshwa ngokubanzi yi-0.4 ~ 1.4, kwaye ukusebenza kwayo kuchatshazelwa kakhulu ngumgangatho wokutshintshwa.

I-CMC inekhono elihle lokubopha, kwaye isisombululo sayo samanzi sinamandla okuxhoma, kodwa akukho xabiso lokwenyani leplastiki.

Xa i-CMC inyibilika, i-depolymerization iyenzeka ngokwenene. I-viscosity iqala ukunyuka ngexesha lokuchithwa, idlula ngobuninzi, kwaye iyancipha kwi-plateau. I-viscosity ebangelwayo inxulumene ne-depolymerization.

Iqondo lokuchithwa kwe-depolymerization lihambelana ngokusondeleyo kunye nobuninzi be-solvent engafanelekanga (amanzi) ekuqulunqweni. Kwinkqubo ye-solvent embi, efana ne-toothpaste ene-glycerin kunye namanzi, i-CMC ayiyi kuchithwa ngokupheleleyo kwaye iya kufikelela kwindawo yokulinganisa.

Kwimeko yoxinaniso lwamanzi olunikiweyo, eyona CMC enehydrophilic ethathelwe indawo kakhulu kulula ukuyikhupha kune-CMC efakwe endaweni ephantsi.

I-Hydroxyethylcellulose (HEC)

I-HEC yenziwe ngokuphatha i-cotton ecocekileyo kunye ne-alkali, kwaye emva koko iphendule nge-ethylene oxide njenge-etherification agent phambi kwe-acetone. Iqondo lokutshintshwa ngokubanzi yi-1.5 ~ 2.0. Ine-hydrophilicity eyomeleleyo kwaye kulula ukufunxa ukufuma.

I-Hydroxyethyl cellulose iyanyibilika emanzini abandayo, kodwa kunzima ukuyinyibilika emanzini ashushu. Isisombululo saso sizinzile kwiqondo lokushisa eliphezulu ngaphandle kwe-gelling.

Izinzile kwii-asidi eziqhelekileyo kunye neziseko. I-alkalis inokukhawulezisa ukuchithwa kwayo kwaye inyuse kancinci i-viscosity yayo. I-dispersibility yayo emanzini imbi kancinane kune-methyl cellulose kunye ne-hydroxypropyl methyl cellulose.

IHydroxypropyl Methyl Cellulose (HPMC)

Ifomula yemolekyuli ye-HPMC yile:

\[C6H7O2(OH)3-mn(OCH3)m,OCH2CH(OH)CH3\]n\]x

IHydroxypropyl methylcellulose luhlobo lweselulosi oluphuma kunye nokusetyenziswa kwayo kunyuka ngokukhawuleza.

I-ether engeyiyo ionic cellulose exutywe ne-ether eyenziwe kwi-cotton ecocekileyo emva kwe-alkalization, isebenzisa i-propylene oxide kunye ne-methyl chloride njenge-etherification agent, ngokusebenzisa uluhlu lweempendulo. Iqondo lokutshintshwa ngokubanzi yi-1.2 ~ 2.0.

Iimpawu zayo zihluke ngenxa yemilinganiselo eyahlukeneyo yomxholo we-methoxyl kunye nomxholo we-hydroxypropyl.

IHydroxypropyl methylcellulose inyibilika ngokulula kumanzi abandayo, kodwa iya kudibana nobunzima ekunyibilikeni kumanzi ashushu. Kodwa ubushushu bayo be-gelation emanzini ashushu buphezulu kakhulu kune-methyl cellulose. Ukunyibilika kumanzi abandayo kuphuculwe kakhulu xa kuthelekiswa ne-methyl cellulose.

I-viscosity ye-hydroxypropyl methylcellulose ihambelana nobunzima bayo be-molecular, kwaye ubukhulu be-molecular weight, buphezulu be-viscosity. Ubushushu buchaphazela i-viscosity yayo, njengoko izinga lokushisa linyuka, i-viscosity iyancipha. Nangona kunjalo, i-viscosity yayo ephezulu inefuthe eliphantsi lobushushu kune-methyl cellulose. Isisombululo sayo sizinzile xa sigcinwe kwiqondo lokushisa.

Ukugcinwa kwamanzi e-hydroxypropyl methylcellulose kuxhomekeke kwisixa sokongeza, i-viscosity, njl.

I-Hydroxypropyl methylcellulose izinzile kwi-asidi kunye ne-alkali, kwaye isisombululo sayo samanzi sizinzileyo kakhulu kwi-pH = 2 ~ 12. I-Caustic soda kunye namanzi e-lime anempembelelo encinci ekusebenzeni kwayo, kodwa i-alkali inokukhawulezisa ukuchithwa kwayo kunye nokwandisa i-viscosity yayo.

I-Hydroxypropyl methylcellulose izinzile kwiityuwa eziqhelekileyo, kodwa xa ukuxinwa kwesisombululo setyuwa kuphezulu, i-viscosity ye-hydroxypropyl methylcellulose isisombululo ivame ukunyuka.

I-Hydroxypropyl methylcellulose inokuxutywa kunye neekhompawundi ze-polymer ezinyibilikayo emanzini ukwenza isisombululo esifanayo kunye ne-viscosity ephezulu. Okufana ne-polyvinyl alcohol, i-starch ether, i-gum yemifuno, njl.

IHydroxypropyl methylcellulose inokumelana ne-enzayim engcono kune-methylcellulose, kwaye isisombululo sayo ayinakwenzeka ukuba sehliswe ngokwe-enzymatic kune-methylcellulose.