Zingaphi iindidi zeselulosi ezikhoyo?

1. Iselulosi ether

Ibakala lokwakha i-cellulose ether ligama eliqhelekileyo loluhlu lweemveliso ezenziwe ngokusabela kwe-alkali cellulose kunye ne-etherifying agent phantsi kweemeko ezithile. I-alkali cellulose ithathelwa indawo ngama-ejenti ahlukeneyo etherifying ukufumana i-ethers ye-cellulose eyahlukeneyo. Ngokweepropathi ze-ionization ze-substituents, i-cellulose ethers inokwahlulwa ibe ngamacandelo amabini: ionic (efana ne-carboxymethyl cellulose) kunye ne-non-ionic (njenge-methyl cellulose). Ngokohlobo lwe-substituent, i-cellulose ether inokohlulwa ibe yi-mono-ether (efana ne-methyl cellulose) kunye ne-ether exutywe (njenge-hydroxypropyl methyl cellulose). Ngokutsho kwe-solubility eyahlukileyo, inokwahlulwa ibe yi-soluble yamanzi (efana ne-hydroxyethyl cellulose) kunye ne-organic solvent-soluble (efana ne-ethyl cellulose), njl njl. yahlulwe ngokohlobo olukhawulezileyo kunye nomgangatho onyangwayo wokulibaziseka uhlobo lokupheliswa.

Indlela yokusebenza ye-cellulose ether kumdaka ihamba ngolu hlobo lulandelayo:

1. Emva kokuba i-cellulose ether kwi-mortar ichithwe emanzini, ukuhanjiswa okusebenzayo kunye okufanayo kwezinto ze-cementitious kwinkqubo kuqinisekiswa ngenxa yomsebenzi ongaphezulu. Njenge-colloid ekhuselayo, i-ether cellulose "isonga" amasuntswana aqinileyo kwaye uwatywine kumphezulu ongaphandle. Yenza ifilimu yokuthambisa, yenza inkqubo yodaka iqine ngakumbi, kwaye iphinde iphucule i-fluidity yodaka ngexesha lokuxuba kunye nokuhamba kakuhle kokwakhiwa.
2. Ngenxa yesakhiwo sayo se-molekyuli, isisombululo se-cellulose ether senza amanzi kumdaka angabi lula ukulahleka, kwaye ngokuthe ngcembe akhuphe ixesha elide, enikezela udaka ngokugcina amanzi kunye nokusebenza kakuhle.

2. I-Methyl cellulose

I-Methylcellulose (MC) ifomula yemolekyuli [C6H7O2(OH)3-h(OCH3) n]x.

Emva kokuba umqhaphu osulungekisiweyo uphathwe ngealkali, i-cellulose ether iveliswa ngothotho lweempendulo ngemethane chloride njenge-etherification agent. Ngokubanzi, iqondo lokutshintsha liyi-1.6 ~ 2.0, kwaye ukunyibilika kwahluka ngokwamanqanaba okutshintsha. yeye-non-ionic cellulose ether.

1. 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.
2. 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 lokupheliswa ikakhulu lixhomekeke kwiqondo lokuguqulwa komphezulu wamasuntswana e-cellulose kunye nokulunga kwamasuntswana. Phakathi kwezi zingentla ze-cellulose ethers, i-methyl cellulose kunye ne-hydroxypropyl methyl cellulose zinezinga eliphezulu lokugcina amanzi.
3. Utshintsho kwiqondo lobushushu kunokuchaphazela ngokunzulu ukugcinwa kwamanzi kwi-methyl cellulose. Ngokuqhelekileyo, okukhona ubushushu buphezulu, kokukhona ukugcinwa kwamanzi kubi. Ukuba ubushushu bomdaka budlula i-40 ° C, ukugcinwa kwamanzi kwe-methyl cellulose kuya kuncitshiswa kakhulu, kuchaphazela kakhulu ukwakhiwa kodaka.
4. I-Methylcellulose inefuthe elibonakalayo ekusebenzeni kunye nokunamathela kodaka. “Ukunamathiswa” apha kubhekiselele kumandla okuncamathelisa okuvakala phakathi kwesixhobo sokufaka isicelo somsebenzi kunye nenxalenye yodonga, oko kukuthi, ukuxhathisa kokucheba kodaka. I-adhesiveness iphezulu, ukuxhathisa kwe-shear yodaka kukhulu, kwaye amandla afunwa ngabasebenzi kwinkqubo yokusetyenziswa nawo mkhulu, kwaye ukwakhiwa kodaka kubi. I-Methyl cellulose adhesion ikwinqanaba eliphakathi kwiimveliso ze-cellulose ether.

3.Hydroxypropyl Methyl Cellulose

Ifomula yemolekyuli ye-hydroxypropyl methylcellulose (HPMC) yi [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.

1. 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.
2. 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.
3. Ukugcinwa kwamanzi e-hydroxypropyl methylcellulose kuxhomekeke kwisixa sokongeza, i-viscosity, njl.
4. 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.
5. 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.
6. IHydroxypropyl methylcellulose inokumelana ne-enzyme engcono kune-methylcellulose, kwaye isisombululo sayo asinakukwazi ukuthotywa nge-enzymes kune-methylcellulose.
7. Ukuncamathelwa kwe-hydroxypropyl methylcellulose kulwakhiwo lodaka luphezulu kunolo lwe-methyl cellulose.

4.Iselulosi yeHydroxyethyl

Iselulosi yeHydroxyethyl (HEC)

Yenziwe kwikotoni esulungekileyo ephathwe nge-alkali, kwaye 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.

1. I-Hydroxyethyl cellulose iyanyibilika emanzini abandayo, kodwa kunzima ukuyinyibilika emanzini ashushu. Isisombululo saso sizinzile kwiqondo lokushisa eliphezulu ngaphandle kwe-gelling. Ingasetyenziselwa ixesha elide phantsi kobushushu obuphezulu kwidaka, kodwa ukugcinwa kwamanzi kwayo kuphantsi kune-methyl cellulose.
2. I-Hydroxyethyl cellulose izinzile kwi-asidi jikelele kunye ne-alkali, kwaye i-alkali inokukhawulezisa ukuchithwa kwayo kwaye yandise i-viscosity yayo. I-dispersibility yayo emanzini imbi kancinane kune-methyl cellulose kunye ne-hydroxypropyl methyl cellulose.
3. Iselulosi yeHydroxyethyl inokusebenza kakuhle kwe-anti-sag kudaka, kodwa inexesha elide lokubuyiswa kwesamente.
4. Ukusebenza kwe-hydroxyethyl cellulose eveliswa ngamanye amashishini asekhaya ngokucacileyo isezantsi kune-methyl cellulose ngenxa yobuninzi bamanzi kunye nomxholo ophezulu wothuthu.

5.Carboxymethyl cellulose

Carboxymethylcellulose (CMC)[C6H7O2(OH)2OCH2COONA] n

I-Ionic cellulose ether yenziwe kwimicu yendalo (ikotoni, njl.njl.) emva kokunyangwa kwe-alkali, kusetyenziswa i-sodium mono-chloroacetate njenge-etherification agent, kwaye iphantsi koluhlu lonyango lokusabela. Iqondo lokutshintshwa ngokubanzi yi-0.4 ~ 1.4, kwaye ukusebenza kwayo kuchatshazelwa kakhulu ngumgangatho wokutshintshwa.

1. I-Carboxymethyl cellulose i-hygroscopic ngakumbi, kwaye iya kuba namanzi amaninzi xa igcinwe phantsi kweemeko eziqhelekileyo.
2. Isisombululo se-Carboxymethyl cellulose samanzi asivelisi ijeli, kwaye i-viscosity iyancipha ngokunyuka kweqondo lokushisa. Xa iqondo lokushisa lidlula i-50 ° C, i-viscosity ayinakuguqulwa.
3. Ukuzinza kwayo kuchaphazeleka kakhulu yi-pH. Ngokuqhelekileyo, inokusetyenziswa kwi-gypsum-based mortar, kodwa kungekhona kwi-samente-based mortar. Xa i-alkaline iphezulu, ilahlekelwa yi-viscosity.
4. Ukugcinwa kwayo kwamanzi kuphantsi kakhulu kune-methyl cellulose. Inempembelelo ebambekayo kwi-gypsum-based mortar kwaye inciphisa amandla ayo. Nangona kunjalo, ixabiso le-carboxymethyl cellulose liphantsi kakhulu kunelo le-methyl cellulose.