Hydroxypropyl methylcellulose (HPMC) bụ ngwakọta polima na-agbaze mmiri na-abụghị ionic nke enwetara site na mgbanwe kemịkalụ nke cellulose eke. A na-ejikarị ya eme ihe n'ọtụtụ ebe na nri, ọgwụ, ihe ịchọ mma na ụlọ ọrụ owuwu, ọkachasị dị ka ihe na-arapara, ihe na-eme ka ihe sie ike, ihe na-eme ka ihe dị nro na ihe na-egbochi ihe n'ime nkwadebe ọgwụ. N'usoro itinye ya, njirimara viscosity nke ngwọta mmiri HPMC dị oke mkpa maka arụmọrụ ya n'ọtụtụ ebe.
1. Nhazi na ihe onwunwe nke hydroxypropyl methylcellulose
Nhazi molekul nke HPMC nwere otu ihe abụọ na-anọchi anya ya, hydroxypropyl (-CH2)₂CHỌCH₃) na methyl (-OCH)₃), nke na-eme ka o nwee ike ịgbaze mmiri nke ọma na mgbanwe. Agbụ ígwè HPMC nwere usoro siri ike, mana ọ nwekwara ike ịmepụta usoro netwọk akụkụ atọ na mmiri mmiri, na-ebute mmụba na viscosity. Ibu molekul ya, ụdị ihe nnọchi na ogo nnọchi (ya bụ, ogo hydroxypropyl na methyl nnọchi nke nkeji ọ bụla) nwere mmetụta dị mkpa na viscosity nke ngwọta ahụ.
2. Àgwà mmiri mmiri nke mmiri mmiri
Àgwà viscosity nke ngwọta mmiri HPMC nwere njikọ chiri anya na ihe ndị dị ka ntinye, ibu molekul, okpomọkụ na uru pH nke ihe mgbaze. N'ozuzu, viscosity nke ngwọta mmiri HPMC na-abawanye ka mmụba nke ntinye ya. viscosity ya na-egosi omume rheological na-abụghị nke Newtonian, ya bụ, ka ọnụego shear na-abawanye, viscosity nke ngwọta ahụ na-ebelata nwayọ nwayọ, na-egosi ihe na-eme ka shear thinning dị.
(1) Mmetụta nke ntinye uche
E nwere njikọ dị n'etiti viscosity nke mmiri ngwọta HPMC na ntinye ya. Ka njupụta nke HPMC na-abawanye, mmekọrịta molekul na mmiri ngwọta na-eme ka ọ dịkwuo mma, njikọ na njikọta nke agbụ molekul na-abawanye, na-ebute mmụba na viscosity nke mmiri ngwọta. Na obere ntinye, viscosity nke mmiri ngwọta HPMC na-abawanye n'usoro ka mmụba nke ntinye, mana na nnukwu ntinye, uto viscosity nke mmiri ngwọta na-adịkarị larịị ma na-eru uru kwụsiri ike.
(2) Mmetụta nke ibu molekul
Ibu molekul nke HPMC na-emetụta kpọmkwem viscosity nke mmiri mmiri ya. HPMC nwere ibu molekul dị elu nwere agbụ molekul dị ogologo ma nwee ike ịmepụta nhazi netwọk atọ dị mgbagwoju anya na mmiri mmiri, na-ebute viscosity dị elu. N'ụzọ dị iche, HPMC nwere ibu molekul dị ala nwere nhazi netwọk dị nro na obere viscosity n'ihi obere agbụ molekul ya. Ya mere, mgbe ị na-etinye ya, ọ dị oke mkpa ịhọrọ HPMC nwere ibu molekul kwesịrị ekwesị iji nweta mmetụta viscosity zuru oke.
(3) Mmetụta nke okpomọkụ
Okpomọkụ bụ ihe dị mkpa na-emetụta viscosity nke mmiri mmiri HPMC. Ka okpomọkụ na-arị elu, mmegharị nke molekul mmiri na-esiwanye ike, viscosity nke mmiri na-ebelatakarị. Nke a bụ n'ihi na mgbe okpomọkụ na-arị elu, nnwere onwe nke yinye molekul HPMC na-abawanye, mmekọrịta dị n'etiti molekul na-ebelatakwa, si otú a na-ebelata viscosity nke mmiri ahụ. Agbanyeghị, nzaghachi nke HPMC site na ụdị dị iche iche ma ọ bụ ụdị dị iche iche ruo na okpomọkụ nwekwara ike ịdị iche, yabụ ọ dị mkpa ka a gbanwee ọnọdụ okpomọkụ dịka ihe achọrọ maka ngwa si dị.
(4) Mmetụta nke uru pH
HPMC n'onwe ya bụ ihe na-abụghị ionic, viscosity nke mmiri ya na-emetụta mgbanwe na pH. Ọ bụ ezie na HPMC na-egosipụta njirimara viscosity kwụsiri ike na gburugburu acidic ma ọ bụ na-anọpụ iche, resolution na viscosity nke HPMC ga-emetụta gburugburu acidic ma ọ bụ alkaline dị oke njọ. Dịka ọmụmaatụ, n'okpuru ọnọdụ acid siri ike ma ọ bụ alkaline siri ike, molekul HPMC nwere ike imebi akụkụ ụfọdụ, si otú a na-ebelata viscosity nke mmiri ya.
3. Nyocha gbasara ọdịdị mmiri nke ihe ngwọta mmiri HPMC
Omume rheological nke ngwọta mmiri HPMC na-egosikarị njirimara mmiri na-abụghị nke Newtonian, nke pụtara na viscosity ya abụghị naanị metụtara ihe ndị dị ka ntinye ngwọta na ibu molekul, kamakwa na ọnụego shear. N'ikwu ya n'ozuzu, na obere ọnụego shear, ngwọta mmiri HPMC na-egosi viscosity dị elu, ebe ka ọnụego shear na-abawanye, viscosity na-ebelata. A na-akpọ omume a "shear thinning" ma ọ bụ "shear thinning" ma dị oke mkpa n'ọtụtụ ojiji bara uru. Dịka ọmụmaatụ, n'ọhịa nke mkpuchi, nkwadebe ọgwụ, nhazi nri, wdg, njirimara shear thinning nke HPMC nwere ike hụ na ejiri viscosity dị elu na-arụ ọrụ n'oge obere ọsọ, ọ nwekwara ike ịgafe ngwa ngwa n'okpuru ọnọdụ shear dị elu.
4. Ihe ndị ọzọ na-emetụta viscosity nke mmiri mmiri HPMC
(1) Mmetụta nke nnu
Mgbakwunye nke ihe na-agbaze nnu (dịka sodium chloride) nwere ike ime ka mmiri HPMC dịkwuo mma. Nke a bụ n'ihi na nnu nwere ike ime ka mmekọrịta dị n'etiti molekul dịkwuo mma site n'ịgbanwe ike ionic nke ihe ngwọta ahụ, ka molekul HPMC wee mepụta nhazi netwọk dị obere, si otú a na-eme ka viscosity dịkwuo elu. Agbanyeghị, a kwesịkwara ịgbanwe mmetụta nke ụdị nnu na ntinye na viscosity dịka ọnọdụ ụfọdụ si dị.
(2) Mmetụta nke ihe mgbakwunye ndị ọzọ
Ịtinye ihe mgbakwunye ndị ọzọ (dịka surfactants, polymers, wdg) na mmiri mmiri HPMC ga-emetụtakwa viscosity. Dịka ọmụmaatụ, surfactants nwere ike ibelata viscosity nke HPMC, ọkachasị mgbe ntinye surfactant dị elu. Na mgbakwunye, ụfọdụ polymers ma ọ bụ ihe ndị dị na ya nwekwara ike imekọrịta ihe na HPMC ma gbanwee njirimara rheological nke mmiri ya.
Mmetụta nke viscosity nke eriri afọhydroxypropyl methylcellulose Ọtụtụ ihe na-emetụta ngwọta mmiri, gụnyere ntinye uche, ibu molekul, okpomọkụ, uru pH, wdg. Ngwọta mmiri HPMC na-egosipụtakarị ihe ndị na-abụghị nke Newtonian rheological, nwere ezigbo ihe ndị na-eme ka ọ dị arọ ma na-eme ka ọ dị nro, a na-ejikwa ya nke ọma n'ọtụtụ ụlọ ọrụ mmepụta ihe na ọgwụ. Ịghọta na ịmụta njirimara viscosity ndị a ga-enyere aka ime ka ojiji HPMC ka mma n'ọtụtụ ngwa dị iche iche. N'ọrụ bara uru, a ga-ahọrọ ụdị na ọnọdụ usoro HPMC kwesịrị ekwesị dịka mkpa ụfọdụ si dị iji nweta viscosity na rheological kacha mma.
Oge ozi: Maachị-01-2025