Hydroxypropyl Methylcellulose E Entsoe ka Eng?

Hydroxypropyl methylcellulose (HPMC) ke polymer ea semisynthetic e sebelisoang liindastering tse ngata, ho kenyelletsa le kaho, lijo, meriana le lihlahisoa tsa tlhokomelo ea botho. E nkoa e le ea bohlokoa bakeng sa bokhoni ba eona ba ho ntlafatsa thepa ea rheological ea metsoako, hammoho le ho lumellana ha eona le lisebelisoa tse ling le chefo ea eona e tlaase. Ho utloisisa hore na HPMC e entsoe joang, ho bohlokoa ho qala ho utloisisa sebopeho le thepa ea selulose.

Cellulose ke ketane e telele ea limolek'hule tsa tsoekere e fumanehang maboteng a lisele tsa limela. Limolek'hule tsa tsoekere li hokahane hammoho ka li-bond tsa beta-1,4-glycosidic, tse etsang ketane e melang. Joale liketane li kopantsoe hammoho ke li-hydrogen bond le matla a Van der Waals ho etsa libopeho tse matla, tse nang le fiber. Cellulose ke motsoako o fumanehang ka bongata ka ho fetisisa lefatšeng, 'me o sebelisoa mefuteng e mengata ea lisebelisoa, ho kenyelletsa pampiri, masela le thepa ea ho haha.

Le hoja cellulose e na le lintho tse ngata tse molemo, hangata e thata haholo 'me ha e qhibilihe hore e ka sebelisoa mekhoeng e mengata. Ho hlola mefokolo ena, bo-ramahlale ba thehile lihlahisoa tse ngata tse fetotsoeng tsa cellulose, ho kenyeletsoa HPMC. HPMC e entsoe ka ho fetola selulose ea tlhaho ka letoto la karabelo ea lik'hemik'hale.

Mohato oa pele oa ho etsa HPMC ke ho fumana thepa ea ho qala ea cellulose. Sena se ka etsoa ka ho ntša selulose mehloling ea limela e kang makhasi a lehong, k'hothone kapa bamboo. Joale selulose e phekoloa ka tharollo ea alkaline, e kang sodium hydroxide kapa potassium hydroxide, ho tlosa litšila le ho senya likhoele tsa cellulose ka likaroloana tse nyenyane. Ts'ebetso ena e tsejoa e le mercerization, 'me e etsa hore cellulose e sebetse haholoanyane le ho e fetola habonolo.

Kamora mercerization, selulose e arajoa ka motsoako oa propylene oxide le methyl chloride ho hlahisa hydroxypropyl le lihlopha tsa methyl mokokotlong oa cellulose. Lihlopha tsa hydroxypropyl li eketsoa ho ntlafatsa ho qhibiliha le ho boloka metsi a selulose, ha lihlopha tsa methyl li eketsoa ho eketsa botsitso le ho fokotsa ts'ebetso ea cellulose. Karabelo e atisa ho etsoa ka pel'a ntho e thusang, e kang sodium hydroxide kapa potassium hydroxide, le tlas'a maemo a laoloang a mocheso, khatello le nako ea ho itšoara.

The degree of substitution (DS) ea HPMC e bolela palo ea lihlopha tsa hydroxypropyl le methyl tse hlahisoang mokokotlong oa cellulose. DS e ka fapana ho latela thepa e lakatsehang ea HPMC le ts'ebeliso e ikhethileng eo e sebelisetsoang eona. Ka kakaretso, litekanyetso tse phahameng tsa DS li fella ka HPMC e nang le viscosity e tlaase le litekanyetso tse potlakileng tsa ho qhibiliha, ha litekanyetso tse tlaase tsa DS li fella ka HPMC e nang le viscosity e phahameng le litekanyetso tse fokolang tsa ho qhibiliha.

Ka mor'a hore karabelo e phethoe, sehlahisoa se hlahisoang se hloekisoa le ho omisoa ho etsa phofo ea HPMC. Ts'ebetso ea tlhoekiso e kenyelletsa ho tlosa lik'hemik'hale life kapa life tse sa sebetsanoang, lihlapolli tse setseng, le litšila tse ling ho HPMC. Hangata sena se etsoa ka ho kopanya mehato ea ho hlatsoa, ​​ho sefa le ho omisa.

Sehlahisoa sa ho qetela ke phofo e tšoeu ho isa ho e tšoeu e sa nkheng le e sa latsoeheng. HPMC e qhibiliha ka metsing le lihlahisoa tse ngata tsa manyolo, 'me e ka etsa li-gel, lifilimi le mehaho e meng ho itšetlehile ka maemo a tšebeliso. Ke polymer e seng ea ionic, ho bolelang hore ha e jare tjhaja efe kapa efe ea motlakase, 'me ka kakaretso e nkuoa e se chefo ebile e bolokehile hore e ka sebelisoa lits'ebetsong tse fapaneng.

HPMC e sebelisoa mefuteng e mengata ea litlolo, ho kenyelletsa lipente, likhomaretsi, li-sealants, meriana le lihlahisoa tsa lijo. Lits'ebetsong tsa kaho, HPMC e atisa ho sebelisoa e le ntho e teteaneng, e kopanyang, le ea pele ea filimi lihlahisoa tse entsoeng ka samente le tsa gypsum, tse kang seretse, li-grouts le metsoako e kopanetsoeng.