Ọmụmụ na njikwa ogo nke Hydroxypropyl Methyl Cellulose

Dị ka ọnọdụ dị ugbu a nke mmepụta HPMC na mba m, a na-enyocha ihe ndị na-emetụta àgwà hydroxypropyl methylcellulose, na na ndabere a, a na-atụle ma na-amụ otú e si eme ka ọkwa dị elu nke hydroxypropyl methylcellulose dị mma.

Isi okwu:hydroxypropyl methylcellulose; àgwà; njikwa; nyocha

Hydroxypropyl methylcellulose (HPMC) bụ cellulose na-abụghị ionic mmiri-soluble agwakọta ether nke sitere na owu, osisi, na etherified na propylene oxide na methyl chloride mgbe alkali ọzịza. Cellulose mix ether bụ Mwepụta gbanwetụrụ nke otu nnọchi ether nwere ihe pụrụ iche karịa nke mbụ monoether, ma nwee ike ịrụ ọrụ nke cellulose ether n'ụzọ zuru oke na nke zuru oke. N'ime ọtụtụ ethers agwakọta, hydroxypropyl methylcellulose bụ ihe kacha mkpa. Usoro nkwadebe bụ ịgbakwunye propylene oxide na alkaline cellulose. Enwere ike ịkọwa HPMC ụlọ ọrụ dị ka ngwaahịa zuru ụwa ọnụ. Ogo nke nnọchi nke otu methyl (uru DS) bụ 1.3 ruo 2.2, na ogo ngbanwe molar nke hydroxypropyl bụ 0.1 ruo 0.8. Enwere ike ịhụ site na data ndị dị n'elu na ọdịnaya na ihe onwunwe nke methyl na hydroxypropyl dị na HPMC dị iche iche, na-eme ka viscosity ngwaahịa ikpeazụ na ọdịiche dị n'iche na-eduga na mgbanwe na àgwà nke ngwaahịa agwụla nke ụlọ ọrụ mmepụta ihe dị iche iche.

Hydroxypropyl methylcellulose na-emepụta ihe ether site na mmeghachi omume kemịkalụ, nke nwere mgbanwe dị ukwuu na nhazi ya, nhazi ya na ihe onwunwe ya, karịsịa solubility nke cellulose, nke nwere ike ịdị iche iche dị ka ụdị na ego nke alkyl dị iche iche ewebata. Nweta ihe mgbaze ether soluble na mmiri, itughari alkali ngwọta, polar solvents (dị ka ethanol, propanol) na ndị na-abụghị polar organic solvents (dị ka benzene, ether), nke ukwuu gbasaa iche na ngwa ubi nke cellulose mmepụta .

1. Mmetụta nke hydroxypropyl methylcellulose alkalization usoro na àgwà

Usoro alkalization bụ nzọụkwụ mbụ na mmeghachi omume nke mmepụta HPMC, ọ bụkwa otu n'ime usoro kachasị mkpa. A na-ekpebikarị ịdị mma nke ngwaahịa HPMC site na usoro alkalization, ọ bụghị usoro etherification, n'ihi na mmetụta alkalization na-emetụta mmetụta nke etherification ozugbo.

Hydroxypropyl methylcellulose na-emekọrịta ihe na ngwọta alkaline iji mepụta alkali cellulose, nke na-emeghachi omume nke ukwuu. Na mmeghachi omume etherification, mmeghachi omume bụ isi nke onye na-ahụ maka etherification na ọzịza, ntinye, na etherification nke cellulose na ọnụego nke mmeghachi omume n'akụkụ, ịdị n'otu nke mmeghachi omume na njirimara nke ngwaahịa ikpeazụ niile metụtara nhazi na nhazi nke alkali cellulose, ya mere, usoro na chemical Njirimara nke alkali cellulose bụ ihe dị mkpa nchọpụta ihe na mmepụta nke cellulose ether.

2. Mmetụta okpomọkụ na ogo hydroxypropyl methylcellulose

N'ime ụfọdụ ntinye nke KOH aqueous solution, ọnụọgụ mgbasa ozi na ogo ọzịza nke hydroxypropyl methylcellulose na alkali na-abawanye na mbelata nke okpomọkụ mmeghachi omume. Dịka ọmụmaatụ, mmepụta nke cellulose alkali dịgasị iche na ntinye nke KOH: 15%, 8% na 10.°C, na 4.2% na 5°C. Usoro nke omume a bụ na nhazi nke cellulose alkali bụ usoro mmeghachi omume exothermic. Ka okpomọkụ na-ebili, mgbasa ozi nke hydroxypropyl methylcellulose na alkali A na-ebelata ego ahụ, ma mmeghachi omume hydrolysis nke alkali cellulose na-abawanye nke ukwuu, nke na-adịghị mma maka ịmepụta cellulose alkali. Enwere ike ịhụ site na nke dị n'elu na iweda ala alkalisation okpomọkụ na-enyere aka na ọgbọ nke cellulose alkali ma na-egbochi mmeghachi omume hydrolysis.

3. Mmetụta nke mgbakwunye na àgwà hydroxypropyl methylcellulose

Na cellulose-KOH-mmiri usoro, ihe mgbakwunye-nnu nwere mmetụta dị ukwuu na nhazi alkali cellulose. Mgbe ntinye nke ngwọta KOH dị ala karịa 13%, mgbasa ozi nke cellulose na alkali adịghị emetụta site na mgbakwunye nke potassium chloride nnu. Mgbe ntinye nke ngwọta lye dị elu karịa 13%, mgbe ọ gbakwụnyere potassium chloride, mgbasa ozi pụtara ìhè nke cellulose na alkali Mgbasa ozi na-abawanye na ntinye nke potassium chloride, ma mkpokọta mgbasa ozi na-ebelata, na mgbasa ozi mmiri na-abawanye nke ukwuu, ya mere, mgbakwunye nke nnu n'ozuzu adịghị mma maka alkalization na ọzịza nke cellulose, ma nnu nwere ike igbochi hydrolysis ma na-edozi usoro ahụ Ọdịnaya mmiri n'efu na-eme ka mmetụta nke alkalization na etherification dịkwuo mma.

4. Mmetụta nke mmepụta usoro na àgwà nke hydroxypropyl methylcellulose

Ka ọ dị ugbu a, ụlọ ọrụ mmepụta ihe hydroxypropyl methylcellulose na obodo m na-ejikarị usoro mmepụta nke usoro mgbaze. The nkwadebe na etherification usoro nke alkali cellulose na-niile rụrụ na inert organic mgbaze, ya mere, akụrụngwa a nụchara anụcha owu kwesịrị ka pulverized iji nweta a ibu n'elu ebe na reactivity iji hụ na àgwà nke okokụre ngwaahịa.

Tinye cellulose a pịrị apị, ihe mgbaze organic na ngwọta alkali n'ime reactor, ma jiri usoro dị ike na-akpali akpali na oge ụfọdụ na oge iji nweta cellulose alkali na alkalization edo na obere mmebi. Organic dilution solvents (isopropanol, toluene, wdg) nwere ụfọdụ inertness, nke na-eme ka hydroxypropyl methylcellulose emit edo okpomọkụ n'oge e guzobere usoro, na-egosi a stepwise ntọhapụ ọganihu, mgbe ibelata hydrolysis mmeghachi omume nke alkali cellulose na-abụghị direction Iji nweta elu- cellulose alkali dị mma, na-abụkarị ntinye nke lye eji na njikọ a dị elu dị ka 50%.

Mgbe a gbasasịrị cellulose na lye, a na-enwetakwa alkali cellulose zuru oke na ọbụna alkalized. Lye osmotically na-aza cellulose nke ọma, na-atọkwa ntọala dị mma maka mmeghachi omume etherification na-esote. Ahụkarị diluents tumadi gụnyere isopropanol, acetone, toluene, wdg The solubility nke lye, ụdị diluent na edemede ọnọdụ bụ isi ihe na-emetụta ndị mejupụtara alkali cellulose. A na-emepụta akwa elu na nke ala mgbe ị na-agwakọta. N'elu oyi akwa bụ isopropanol na mmiri, na ala oyi akwa bụ nke alkali na obere ego nke isopropanol. The cellulose gbasasịrị na usoro bụ n'ụzọ zuru ezu na kọntaktị na elu na ala mmiri mmiri n'ígwé n'okpuru n'ibu edemede. Alkali dị na sistemu mmiri na-agbanwe agbanwe ruo mgbe e guzobere cellulose.

Dị ka ihe na-ahụkarị cellulose na-abụghị ionic ngwakọta ether, ọdịnaya nke hydroxypropyl methylcellulose otu dị na dị iche iche macromolecular chains, ya bụ, nkesa ruru nke methyl na hydroxypropyl otu dị iche na C nke ọ bụla glucose mgbanaka mgbanaka. Ọ nwere nnukwu mgbasa na enweghị usoro, na-eme ka ọ sie ike ikwe nkwa nkwụsi ike nke ngwaahịa ahụ.