Ikhwalithi yeHydroxypropyl Methyl Cellulose

IHydroxypropyl methylcellulose icolisiswa ukotini ngemva kokwenziwa kwe-alkalization, kusetshenziswa i-propylene oxide ne-methyl chloride njengama-etherification agents, futhi ibhekana nochungechunge lokusabela ukuze kukhiqizwe i-ether engeyona ionic cellulose. IHydroxypropyl methylcellulose iyi-ether engeyona ionic cellulose, emhlophe ngokubukeka, ayinaphunga futhi ayinambitheki. Izinga lokushintsha ngokuvamile . Izakhiwo zayo ziyahlukahluka kuye ngesilinganiso sokuqukethwe kwe-methoxyl kokuqukethwe kwe-hydroxypropyl.

Okokuqala, bheka kuqala ukuhlanganiswa kwe-hydroxypropyl methylcellulose:

I-cotton cellulose ecolisisiwe iphathwa ngesisombululo se-alkali ku-35-40 ° C isigamu sehora, icindezelwe, bese i-cellulose igaywe ku-35 ° C futhi iguge ngendlela efanele, ukuze izinga elijwayelekile le-polymerization ye-alkali fiber etholakalayo ibe ngaphakathi ububanzi obudingekayo. Faka i-alkali fibre ethangini le-etherification, engeza i-propylene oxide ne-methyl chloride ngokulandelana, i-etherify ku-50-80°C amahora angu-5, futhi ingcindezi enkulu icishe ibe. Bese wengeza inani elifanele le-hydrochloric acid ne-oxalic acid emanzini ashisayo ku-90°C ukuze wandise ivolumu. Dehydrate in a centrifuge. Uma umswakama wempahla ungaphansi kuka-60%, yigeze ukuze ingathathi hlangothi, bese uyomisa ibe ngaphansi kuka-5% ngokugeleza komoya oshisayo ku-130°C. Ekugcineni waphihliza ngesisefo esinezikhala ezingama-20 ukuze uthole umkhiqizo osuphelile.

Izici zomkhiqizo we-Hydroxypropyl Methyl Cellulose:

1. IHydroxypropyl methylcellulose incibilika kalula emanzini abandayo futhi izoncibilika emanzini ashisayo. Kodwa-ke, izinga lokushisa layo le-gelation emanzini ashisayo liphakeme kakhulu kunalelo le-methylcellulose. Ukuncibilika emanzini abandayo nakho kuba ngcono kakhulu kune-methyl cellulose.

2. I-viscosity ye-hydroxypropyl methylcellulose ihlobene nesisindo samangqamuzana, futhi i-viscosity iphezulu uma isisindo samangqamuzana sikhulu. Ukushisa nakho kuthinta i-viscosity yayo, njengoba izinga lokushisa likhuphuka, i-viscosity iyancipha. Kodwa i-viscosity yayo ephezulu iphansi kune-methyl cellulose. Isixazululo saso sizinzile ekamelweni lokushisa.

Amandla okugcina amanzi e-hydroxypropyl methylcellulose ancike enanini layo elingeziwe, i-viscosity, njll., futhi izinga layo lokugcinwa kwamanzi lingaphezulu kwele-methyl cellulose.

3. I-Hydroxypropyl methylcellulose izinzile ku-asidi ne-alkali, futhi isisombululo sayo esinamanzi sizinzile ebangeni le-pH=2-12. I-Caustic soda namanzi e-lime anethonya elincane ezindaweni zayo, kodwa i-alkali ingasheshisa ukuchithwa kwayo futhi ikhulise kancane i-viscosity yayo. I-Hydroxypropyl methylcellulose izinzile kusawoti ovamile, kodwa lapho ukugxila kwesisombululo sikasawoti kuphezulu, i-viscosity yesisombululo se-hydroxypropyl methylcellulose ivame ukwanda.

4. I-Hydroxypropyl methylcellulose ingaxutshwa nama-polymers ancibilikayo emanzini ukuze enze isisombululo esifanayo, esiphezulu se-viscosity. Okufana ne-polyvinyl alcohol, amanzi echibi i-ether powder, i-vegetable gum, njll.

I-Hydroxypropyl methylcellulose inokumelana ne-enzyme okungcono kune-methylcellulose, futhi isisombululo sayo mancane amathuba okuthi sonakaliswe nge-enzymatic kune-methylcellulose.

5. Ukunamathela phakathi kwe-hydroxypropyl methylcellulose kanye nesakhiwo sodaka kuphakeme kunaleyo ye-methylcellulose.

Udaka oluxubene olumanzi luwusimende, isamba esihle, izithasiselo namanzi, futhi izingxenye ezihlukahlukene zinqunywa ngokuya ngokusebenza. Ngemuva kokuthi ukuxuba kulinganiswa futhi kuxutshwe ngesilinganiso esithile esiteshini sokuxuba, ingxube ihanjiswa endaweni yokusetshenziswa iloli yokuxuba futhi igcinwe esitsheni esikhethekile, futhi ingxube emanzi isetshenziswa ngesikhathi esithile.

Ungahlulela kanjani ikhwalithi ye-hydroxypropyl methylcellulose?

Uma ubheka ikhwalithi ye-hydroxypropyl methylcellulose ikakhulukazi kuncike ezinkomba ezimbili, eyodwa iyizinga lokushintsha (DS) kanti enye ubumsulwa. Ngokuvamile, izakhiwo ze-carboxymethyl cellulose zihlukile uma izinga lokushintsha lihlukile; izinga lokushintsha liphakeme, kuqina ukuncibilika, kanye nokuba sobala nokuzinza kwesixazululo. Ngokwemibiko efanele, ukucaca kwe-carboxymethyl cellulose kuhle uma izinga lokushintsha lingu-~, futhi i-viscosity yesisombululo sayo esinamanzi iphezulu uma inani le-pH lingu-6-9. Okusho ukuthi, ukukala ikhwalithi ye-carboxymethyl cellulose, kuyadingeka ukuqonda kahle izinga layo lokushintshwa nokuhlanzeka. Lezi zinkomba ezimbili zihlangabezana nezidingo, okusho ukuthi izinga layo lihle kakhulu.