Umgangatho weHydroxypropyl Methyl Cellulose

I-Hydroxypropyl methylcellulose isulungekiswa kwikotoni emva kwe-alkalization, isebenzisa i-propylene oxide kunye ne-methyl chloride njengee-etherification agents, kwaye ithatha uchungechunge lweempendulo ukuvelisa i-ether engekho i-ionic cellulose. IHydroxypropyl methylcellulose yi-ether ye-cellulose engeyo-ionic, imhlophe ngenkangeleko, ayinavumba kwaye ayinancasa. Iqondo lokutshintshwa ngokubanzi . Iimpawu zayo ziyahluka ngokuxhomekeka kumlinganiselo we-methoxyl umxholo kumxholo we-hydroxypropyl.

Okokuqala, jonga kuqala kwi-synthesis ye-hydroxypropyl methylcellulose:

I-cotton cellulose ecocekileyo iphathwa ngesisombululo se-alkali kwi-35-40 ° C kwisiqingatha seyure, icinezelwe, kwaye i-cellulose ihlanjululwe kwi-35 ° C kwaye igugile ngokufanelekileyo, ukwenzela ukuba i-degree degree ye-polymerization ye-alkali fiber efunyenweyo ingaphakathi uluhlu olufunekayo. Faka i-alkali fiber kwi-tank etherification, yongeza i-propylene oxide kunye ne-methyl chloride ngokulandelelana, i-etherify kwi-50-80 ° C kwiiyure ze-5, kwaye uxinzelelo oluphezulu luyi-approx. Emva koko faka inani elifanelekileyo le-hydrochloric acid kunye ne-oxalic acid kumanzi ashushu kwi-90 ° C ukwandisa umthamo. Dehydrate kwicentrifuge. Xa ubumanzi bezinto eziphathekayo bungaphantsi kwe-60%, yihlambe ukuba ingathathi hlangothi, uze uyomise ibe ngaphantsi kwe-5% kunye nokuhamba komoya oshushu kwi-130 ° C. Ekugqibeleni watyhoboza ngesihluzo se-20-mesh ukufumana imveliso egqityiweyo.

Iimpawu zeMveliso yeHydroxypropyl Methyl Cellulose:

1. IHydroxypropyl methylcellulose inyibilika ngokulula emanzini abandayo kwaye iya kunyibilika emanzini ashushu. Nangona kunjalo, ubushushu bayo be-gelation emanzini ashushu buphezulu kakhulu kune-methylcellulose. Ukunyibilika kumanzi abandayo kuphuculwe kakhulu ngaphezu kwe-methyl cellulose.

2. I-viscosity ye-hydroxypropyl methylcellulose ihambelana nesisindo se-molecular, kwaye i-viscosity iphezulu xa ubunzima be-molecular bukhulu. Ubushushu buchaphazela i-viscosity yayo, njengoko izinga lokushisa linyuka, i-viscosity iyancipha. Kodwa i-viscosity yayo ephezulu ingaphantsi kune-methyl cellulose. Isisombululo saso sizinzile kwiqondo lokushisa.

Umthamo wokugcina amanzi we-hydroxypropyl methylcellulose kuxhomekeke kwisixa sokongeza, i-viscosity, njl., kwaye izinga lokugcinwa kwamanzi liphezulu kunelo le-methyl cellulose.

3. I-Hydroxypropyl methylcellulose izinzile kwi-asidi kunye ne-alkali, kwaye isisombululo sayo samanzi sizinzile kwi-pH = 2-12. I-Caustic soda kunye namanzi e-lime anempembelelo encinci kwiipropati zayo, kodwa i-alkali inokukhawulezisa ukuchithwa kwayo kwaye yandise i-viscosity yayo. I-Hydroxypropyl methylcellulose izinzile kwiityuwa eziqhelekileyo, kodwa xa ukuxinwa kwesisombululo setyuwa kuphezulu, i-viscosity yesisombululo se-hydroxypropyl methylcellulose ivame ukunyuka.

4. I-Hydroxypropyl methylcellulose inokuxutywa kunye neepolymers ezinyibilikayo zamanzi ukwenza i-uniform, isisombululo esiphezulu se-viscosity. Okufana ne-polyvinyl alcohol, i-ether yomgubo wamanzi echibi, itshungama yemifuno, njl.

I-Hydroxypropyl methylcellulose inokumelana ne-enzyme engcono kune-methylcellulose, kwaye isisombululo sayo asinakukwazi ukutshatyalaliswa kwe-enzymatic kune-methylcellulose.

5. Ukudibanisa phakathi kwe-hydroxypropyl methylcellulose kunye nesakhiwo sodaka siphezulu kune-methylcellulose.

Udaka oluxutyiweyo olumanzi yisamente, i-aggregate efanelekileyo, izongezo kunye namanzi, kunye namacandelo ahlukeneyo anqunywe ngokwentsebenzo. Emva kokuba ukuxuba kulinganiswe kwaye kuxutywe kumlinganiselo othile kwisikhululo sokuxuba, umxube uthunyelwa kwindawo yokusetyenziswa iloli yokuxuba kwaye igcinwe kwisitya esikhethekileyo, kwaye umxube omanzi usetyenziswe ngexesha elithile.

Ungawugweba njani umgangatho we-hydroxypropyl methylcellulose?

Ukuqwalasela umgangatho we-hydroxypropyl methylcellulose ikakhulu kuxhomekeke kwizikhombisi ezibini, enye iqondo lokuthatha indawo (DS) kwaye enye yibunyulu. Ngokubanzi, iipropathi ze-carboxymethyl cellulose zahlukile ukuba iqondo lokutshintsha lihlukile; iqondo eliphezulu lokutshintshwa, lomelele ukunyibilika, kwaye ngcono ukungafihli kunye nokuzinza kwesisombululo. Ngokweengxelo ezifanelekileyo, ukucaca kwe-carboxymethyl cellulose kulungile xa iqondo lokutshintshwa li- ~, kunye ne-viscosity yesisombululo sayo samanzi siphezulu xa ixabiso le-pH liyi-6-9. Oko kukuthi, ukulinganisa umgangatho we-carboxymethyl cellulose, kuyimfuneko ukuqonda kakuhle iqondo lokutshintshwa kunye nokucoceka. Ezi zikhombisi zimbini zihlangabezana neemfuno, oku kuthetha ukuba umgangatho wayo uhle kakhulu.