Thuto ka Taolo ea Boleng ea Hydroxypropyl Methyl Cellulose

Ho ea ka boemo ba hona joale ba tlhahiso ea HPMC naheng ea heso, lintlha tse amang boleng ba hydroxypropyl methylcellulose li hlahlojoa, 'me motheong ona, mokhoa oa ho ntlafatsa boemo ba boleng ba hydroxypropyl methylcellulose o tšohloa le ho ithutoa, e le hore o kene tlhahiso.

Mantsoe a bohlokoa:hydroxypropyl methylcellulose; boleng; taolo; lipatlisiso

Hydroxypropyl methylcellulose (HPMC) ke selulose e se nang ionic e qhibilihang ka metsing e entsoeng ka k'hothone, lehong, 'me e entsoe ka propylene oxide le methyl chloride ka mor'a ho ruruha ha alkali. Cellulose mixed ether is The modified derivative of single substituent ether e na le thepa e ikhethang e betere ho feta monoether ea mantlha, 'me e ka bapala ts'ebetso ea cellulose ether ka botlalo le ka mokhoa o phethahetseng. Har'a li-ether tse ngata tse tsoakiloeng, hydroxypropyl methylcellulose ke eona ea bohlokoa ka ho fetisisa. Mokhoa oa ho itokisa ke ho eketsa propylene oxide ho selulose ea alkaline. HPMC ea indasteri e ka hlalosoa e le sehlahisoa sa bokahohle. Tekanyo ea ho kenya sebaka sa sehlopha sa methyl (DS value) ke 1.3 ho 2.2, 'me tekanyo ea molar substitution ea hydroxypropyl ke 0.1 ho 0.8. E ka bonoa ho tsoa boitsebisong bo ka holimo hore litaba le thepa ea methyl le hydroxypropyl ho HPMC li fapane, e leng se etsang hore ho be le viscosity ea ho qetela ea sehlahisoa le Phapang ea ho lumellana ho lebisa ho feto-fetoha ha boleng ba lihlahisoa tse felileng tsa likhoebo tse sa tšoaneng tsa tlhahiso.

Hydroxypropyl methylcellulose e hlahisa li-derivatives tsa ether ka karabelo ea lik'hemik'hale, tse nang le liphetoho tse tebileng sebopeho sa eona, sebopeho le thepa, haholo-holo ho qhibiliha ha selulose, e ka fapanyetsanoang ho ea ka mofuta le palo ea lihlopha tsa alkyl tse hlahisitsoeng. Fumana lintho tse tsoang ho ether tse qhibilihang ka metsing, tharollo ea alkali e hlapollang, metsoako ea polar (e kang ethanol, propanol) le metsoako ea tlhaho e sa polar (e kang benzene, ether), e ntlafatsang haholo mefuta le likarolo tsa ts'ebeliso ea lihlahisoa tsa cellulose.

1. Phello ea hydroxypropyl methylcellulose alkalization process ka boleng

Ts'ebetso ea alkalization ke mohato oa pele mohatong oa karabelo oa tlhahiso ea HPMC, hape ke e 'ngoe ea mehato ea bohlokoahali. Boleng ba tlhaho ba lihlahisoa tsa HPMC bo khethoa haholo ke ts'ebetso ea alkalization, eseng ts'ebetso ea etherification, hobane phello ea alkalization e ama ka kotloloho phello ea etherification.

Hydroxypropyl methylcellulose e sebelisana le tharollo ea alkaline ho etsa alkali cellulose, e sebetsang haholo. Karabelong ea etherification, karabelo e kholo ea moemeli oa etherification ho ho ruruha, ho kenella, le etherification ea selulose le Sekhahla sa karabelo ea lehlakore, ho tšoana ha karabelo le thepa ea sehlahisoa sa ho qetela kaofela li amana le sebopeho le sebopeho sa. alkali cellulose, kahoo sebopeho le thepa ea lik'hemik'hale tsa selulose ea alkali ke lintho tsa bohlokoa tsa ho etsa lipatlisiso tlhahiso ea cellulose ether.

2. Phello ea mocheso ho boleng ba hydroxypropyl methylcellulose

Motsoakong o itseng oa tharollo ea metsi ea KOH, tekanyo ea adsorption le tekanyo ea ho ruruha ha hydroxypropyl methylcellulose ho alkali e eketseha ka ho fokotseha ha mocheso oa karabelo. Mohlala, tlhahiso ea selulose ea alkali e fapana ho latela bongata ba KOH: 15%, 8% ho 10.°C, le 4.2% ho 5°C. Mokhoa oa mokhoa ona ke hore ho thehoa ha selulose ea alkali ke ts'ebetso ea exothermic reaction. Ha mocheso o ntse o phahama, adsorption ea hydroxypropyl methylcellulose ka alkali Chelete e fokotsehile, empa karabelo ea hydrolysis ea alkali cellulose e eketseha haholo, e sa lumellaneng le ho thehoa ha alkali cellulose. Ho ka bonoa ho tsoa ka holimo hore ho theola mocheso oa alkalization ho thusa ho hlahisa alkali cellulose le ho thibela karabelo ea hydrolysis.

3. Phello ea li-additives ho boleng ba hydroxypropyl methylcellulose

Ka selulose-KOH-metsi tsamaiso, ho eketsa-letsoai le na le tšusumetso e kholo ho thehoeng ha selulose ea alkali. Ha motsoako oa tharollo ea KOH o le tlase ho 13%, ho kenngoa ha cellulose ho alkali ha ho amehe ke ho eketsoa ha letsoai la potassium chloride. Ha motsoako oa tharollo ea lye e phahame ho feta 13%, ka mor'a ho eketsa potassium chloride, ho bonahala eka ho na le selulose ho alkali The adsorption e eketseha ka mahloriso a potassium chloride, empa matla a adsorption a fokotseha, 'me metsi a adsorption a eketseha haholo. Ho phaella ha letsoai ka kakaretso ha ho ratehe ho alkalization le ho ruruha ha selulose, empa letsoai le ka thibela hydrolysis le ho laola tsamaiso ea metsi a sa lefelloeng ka tsela eo e ntlafatsa phello ea alkalization le etherification.

4. Tšusumetso ea ts'ebetso ea tlhahiso ho boleng ba hydroxypropyl methylcellulose

Hajoale, likhoebo tsa tlhahiso ea hydroxypropyl methylcellulose naheng ea heso hangata li nka mokhoa oa tlhahiso ea mokhoa oa solvent. Tshebetso ea ho lokisa le etherification ea selulose ea alkali kaofela e etsoa ka motsoako oa inert organic, kahoo k'hothone e hloekisitsoeng e hloka ho siloa ho fumana sebaka se seholoanyane sa Surface le reactivity ho netefatsa boleng ba sehlahisoa se felileng.

Kenya pulverized cellulose, organic solvent le alkali solution ho reactor, 'me u sebelise matla a susumetsang a mochine ka mocheso o itseng le nako ho fumana selulose ea alkali e nang le alkalization e tšoanang le ho senyeha ho fokolang. Organic dilution solvents (isopropanol, toluene, joalo-joalo) na le inertness itseng, e leng se etsang hore hydroxypropyl methylcellulose emit junifomo mocheso nakong ea tshebetso ya sebopeho, ho bontša stepwise tokollo tsoelo-pele, ha a ntse a fokotsa hydrolysis itsoara joang ka alkali selulose ka lehlakoreng le leng Ho fumana phahameng- boleng ba selulose ea alkali, hangata bongata ba lye bo sebelisitsoeng sehokelong sena bo phahame joalo ka 50%.

Kamora hore cellulose e kolobisoe ka har'a lye, ho fumanoa selulose ea alkali e ruruhileng ka ho felletseng le ka mokhoa o lekanang. Lye osmotically e ruruha selulose hantle, e rala motheo o motle bakeng sa karabelo e latelang ea etherification. Li-diluents tse tloaelehileng haholo-holo li kenyelletsa isopropanol, acetone, toluene, joalo-joalo The solubility ea lye, mofuta oa maemo a hlapollang le a susumetsang ke lintlha tse ka sehloohong tse amang ho hlophisoa ha selulose ea alkali. Likarolo tse ka holimo le tse ka tlaase li thehoa ha li kopanya. Lera le ka holimo le entsoe ka isopropanol le metsi, 'me karolo e ka tlaase e entsoe ka alkali le palo e nyenyane ea isopropanol. Selulose e qhalakantsoeng tsamaisong e amana ka ho feletseng le likarolo tsa metsi tse ka holimo le tse ka tlaase tlas'a ho sisinyeha ha mechine. Alkali tsamaisong Tekanyo ea metsi e fetoha ho fihlela cellulose e thehoa.

Joalo ka ether e tloaelehileng ea cellulose e seng ionic e tsoakiloeng, litaba tsa lihlopha tsa hydroxypropyl methylcellulose li ho liketane tse fapaneng tsa macromolecular, ke hore, karolelano ea kabo ea lihlopha tsa methyl le hydroxypropyl e fapane ho C ea boemo bo bong le bo bong ba lesale la tsoekere. E na le ho hasana ho hoholo le ho sa tloaelehang, ho etsa hore ho be thata ho netefatsa botsitso ba boleng ba sehlahisoa.