I-Methyl Cellulose (MC) I-molecular formula \[C6H7O2(OH)3-h(OCH3)n1] x Ikotoni esulungekileyo iphathwa nge-alkali, kwaye i-methyl chloride isetyenziswa njenge-etherification agent. Emva koluhlu lweempendulo, unyango lwe-cellulose ether luyenziwa. Ngokuqhelekileyo, iqondo lokutshintshwa yi-1.6 ~ 2.0, kwaye iqondo lokuthatha indawo lihlukile. yeye-non-ionic cellulose ether.
1. I-Methylcellulose i-soluble emanzini abandayo, amanzi ashushu aya kuhlangabezana nobunzima, kwaye uluhlu lwe-pH lwesisombululo samanzi luzinzile kakhulu phakathi kwe-3/12. Isitatshi, iguar gum kunye nezinye ii-surfactants ezininzi ziyahambelana. I-Gelation iyenzeka xa iqondo lokushisa lifikelela kwiqondo lokushisa.
Ukugcinwa kwamanzi kwe-methylcellulose kuxhomekeke kwisixa esongezelelweyo, i-viscosity, i-particle fineness kunye nesantya sokuchithwa. Ukwandiswa ngokubanzi, encinci, i-viscosity ephezulu, ukugcinwa kwamanzi aphezulu. Phakathi kwabo, ukugcinwa kwamanzi kunempembelelo enkulu, kwaye inqanaba le-viscosity alilingani ngokuthe ngqo nokugcinwa kwamanzi. Isantya sokuchithwa ikakhulu sixhomekeke kwiqondo lokuguqulwa komphezulu weengqungquthela ze-cellulose kunye nobuhle beengqungquthela. Phakathi kwezi zingentla ze-cellulose ethers, i-methyl cellulose kunye ne-hydroxypropyl methyl cellulose inokugcinwa kwamanzi okuphezulu.
Utshintsho lobushushu lunokuchaphazela ngokunzulu ukugcinwa kwamanzi kwi-methyl cellulose. – Ukuphakama kweqondo lobushushu, kokukhona ukugcinwa kwamanzi kubi. Ukuba ubushushu bomdaka budlula i-40 ° C, ukugcinwa kwamanzi kwe-methyl cellulose kuya kuncitshiswa kakhulu, kuchaphazela kakhulu ukwakhiwa kodaka.
I-Methylcellulose inefuthe elibonakalayo ekusebenzeni kunye nokunamathela kodaka. "Ukunamathela" apha kubhekiselele ekunamatheleni phakathi kwesixhobo sokufaka isicelo somsebenzi kunye ne-substrate eludongeni, oko kukuthi, ukuxhathisa kwe-shear yodaka. I-viscosity, amandla okucheba udaka, kunye namandla afunwa ngabasebenzi abasetyenziswayo nawo makhulu kakhulu, kwaye ukwakhiwa kodaka akulunganga. I-Methylcellulose ibambelele kumanqanaba aphakathi kwiimveliso ze-cellulose ether.
2. I-Hydroxypropyl methylcellulose (HPMC) [C 6 H 7 O 2 (OH) 3-mn (OCH 3 ) m, OCH 2 CH (OH) CH 3] n]] i-hydroxypropyl methyl cellulose Kwiminyaka yakutshanje, iintlobo zeselulosi zine anda ngokukhawuleza. I-cellulose engeyiyo i-ionic exutywe i-ether elungiselelwe ngoluhlu lweempendulo emva kwe-alkalization ye-alkali ye-cotton ecocekileyo, apho i-propylene oxide kunye ne-methyl chloride zisetyenziswa njengee-etherification agents. Iqondo lokutshintsha liqhelekile ukuba yi-1.2/2.0. Iipropati zayo ziyahluka ngokomlinganiselo we-methoxyl umxholo kunye nomxholo we-hydroxypropyl.
1. I-Hydroxypropyl methylcellulose yahlulwe ngohlobo olushushu oluncibilikayo kunye nohlobo olukhawulezayo. Ubushushu bayo be-gelation emanzini ashushu buphezulu kakhulu kune-methylcellulose. Kwakhona kubonisa ukuphucuka okukhulu kwi-methylcellulose xa inyibilika emanzini abandayo.
I-viscosity ye-hydroxypropyl methylcellulose ihambelana nesisindo se-molecular, kwaye ubunzima be-molecular buphezulu. Ubushushu buchaphazela i-viscosity yayo, njengoko izinga lokushisa linyuka, i-viscosity iyancipha. Nangona kunjalo, impembelelo yobushushu kwi-viscosity iphantsi kune-methyl cellulose. Isisombululo yindawo yokugcina kwiqondo lokushisa.
3. Ukugcinwa kwamanzi kwe-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 ye-2/12. Ukusebenza kwe-caustic soda kunye namanzi e-lime ayinayo impembelelo eninzi, kodwa i-alkali inokukhawulezisa izinga lokuchithwa kwayo, kwaye i-viscosity iyanda. I-Hydroxypropyl methylcellulose izinzile kwiityuwa eziqhelekileyo, kodwa xa ukuxinwa kwesisombululo setyuwa kuphezulu, i-viscosity yesisombululo se-hydroxypropyl methylcellulose ivame ukunyuka.
I-Hydroxypropyl methylcellulose inokuxutywa kunye neepolymers ezinyibilikayo zamanzi ukwenza iyunifomu, isisombululo esiphezulu se-viscosity. Okufana ne-polyvinyl alcohol, i-starch ether, i-gum yemifuno, njl.
I-Hydroxypropyl methylcellulose inokumelana ne-enzyme engcono kune-methylcellulose, ukuba kunokwenzeka ukuchithwa kwe-enzymatic yesisombululo sayo kuncinci kune-methylcellulose, kwaye ukunamathela kwe-hydroxypropylmethylcellulose kukwakhiwa kodaka kuphezulu kune-methylcellulose. isiseko se-cellulose.
Isithathu, i-hydroxyethyl cellulose (HEC) yenziwe kwikotoni esulungekileyo ephathwa ngealkali, phambi kwe-acetone, kunye ne-ethylene oxide njenge-etherification agent. Iqondo layo lokutshintshwa lidla ngokuba yi-1.5/2.0. Ine-hydrophilicity eyomeleleyo kwaye kulula ukufunxa ukufuma.
1. I-Hydroxyethyl cellulose iyanyibilika emanzini abandayo, kodwa kunzima ukunyibilika emanzini ashushu. Isisombululo sizinzile kwiqondo lokushisa eliphezulu kwaye asinayo i-gel properties. Ingasetyenziselwa ixesha elide kwi-high-temperature mortar, kodwa ukugcinwa kwayo kwamanzi kuphantsi kune-methyl cellulose.
2. I-Hydroxyethyl cellulose izinzile kwi-asidi ngokubanzi kunye ne-alkali. I-alkali ikhawulezisa ukuchithwa kwayo, kwaye i-viscosity yayo inyuka kancinane. Ukusasazwa kwayo emanzini kubi kancinci kune-methyl cellulose kunye ne-hydroxypropyl methyl cellulose.
3. I-Hydroxyethyl cellulose inomsebenzi omhle wokuchasana nokuxhoma kumdaka, kodwa ixesha elide, enye i-hydroxyethyl cellulose eveliswa ekhaya inokusebenza okuphantsi kakhulu kune-methyl cellulose ngenxa yobuninzi bamanzi kunye nomxholo ophezulu wothuthu.
4. I-Carboxymethyl cellulose (CMC) \ [C6H7O2 (OH) 2och2COONa] (i-cotton, njl.) ye-fiber yendalo iphathwa nge-alkali, kwaye i-sodium chloroacetate isetyenziswe njenge-etherification agent, emva koluhlu lwezonyango zokuphendula, lwenziwa kwi-ionic. i-cellulose ether. Iqondo lokutshintshwa ngokubanzi ngu-0.4/1.4, kwaye iqondo lokutshintsha linempembelelo enkulu ekusebenzeni.
I-Carboxymethyl cellulose ine-hygroscopicity ephezulu, kwaye iimeko zokugcinwa ngokubanzi ziqulethe amanzi amaninzi.
2. I-Carboxymethyl cellulose isisombululo samanzi asivelisi i-gel, i-viscosity iyancipha xa iqondo lokushisa likhuphuka, kwaye i-viscosity ayinakuguqulwa xa izinga lokushisa lidlula i-50 ° C.
Ukuzinza kwayo kuchaphazeleka kakhulu yi-pH. Ngokuqhelekileyo isetyenziselwa udaka lwegypsum, hayi udaka lwesamente. Kwimeko ye-alkalinity ephezulu, iya kulahlekelwa yi-viscosity yayo.
Ukugcinwa kwayo kwamanzi kuphantsi kakhulu kune-methyl cellulose. Udaka lwe-Gypsum lunempembelelo yokunciphisa, ukunciphisa amandla. Kodwa ixabiso le-carboxymethyl cellulose liphantsi kakhulu kunelo le-methyl cellulose.
Ixesha lokuposa: Jan-13-2023