Hydroxypropyl methylcellulose (HPMC) waa iskudhis aan-ionic biyo-milmi kara oo lagu helay wax ka beddelka kiimikaad ee cellulose dabiiciga ah. Waxaa si weyn loogu isticmaalaa cuntada, daawooyinka, isqurxinta iyo warshadaha dhismaha, gaar ahaan sida xabagta, dhumucdiisuna, emulsifier iyo wakiilka hakinta ee diyaarinta daawooyinka. Habka codsiga, sifooyinka viscosity ee xal aqueous HPMC ayaa muhiim u ah waxqabadkeeda meelo kala duwan.
1. Qaab dhismeedka iyo sifooyinka hydroxypropyl methylcellulose
Qaab dhismeedka molecular ee HPMC waxa uu ka kooban yahay laba kooxood oo beddela, hydroxypropyl (-CH₂CHOOHCH₃) iyo methyl (-OCH₃), taas oo ka dhigaysa in ay leedahay milmi-biyood wanaagsan iyo karti wax-ka-beddelid. Silsiladda molecular ee HPMC waxay leedahay qaab-dhismeed adag oo gaar ah, laakiin waxay sidoo kale samayn kartaa qaab-dhismeedka shabakad saddex-geesood ah oo ku jira xalka aqueous, taasoo keentay kororka viscosity. Miisaankeeda kelli, nooca beddelka iyo heerka beddelka (ie, heerka hydroxypropyl iyo beddelka methyl ee unug kasta) waxay saameyn muhiim ah ku leeyihiin duleelka xalka.
2. sifooyinka viscosity ee xal aqueous
Tilmaamaha viscosity ee xal aqueous HPMC waxay si dhow ula xiriiraan arrimaha sida fiirsashada, miisaanka kelli, heerkulka iyo qiimaha pH ee dareeraha. Guud ahaan, viscosity ee xal aqueous HPMC kordhiyaa kororka ee ay diiradda. Viscosity-keedu wuxuu muujinayaa habdhaqan rheological non-Newtonian, taas oo ah, marka heerka xiiridu kordho, viscosity ee xalka si tartiib tartiib ah hoos u dhaco, muujinaysaa ifafaale khafiifinta xiiran.
(1) Saamaynta feejignaanta
Waxa jira xidhiidh gaar ah oo u dhexeeya viscosity ee xal aqueous HPMC iyo fiirsashada. Marka xoogga la saaro HPMC uu kordho, isdhexgalka molecular ee xalka aqueous waa la wanaajiyey, iyo isku-xidhka iyo isku-xirnaanta silsiladaha kelliyadu way kordhaan, taasoo keentay kororka viscosity ee xalka. Heerarka hoose, viscosity ee xal aqueous HPMC si toos ah u kordhiyaa kor u fiirsashada, laakiin at fiirsashada sare, korriinka viscosity ee xal u janjeera inuu noqdo mid siman oo gaadho qiimo deggan.
(2) Saamaynta miisaanka unugyada
Miisaanka kelli ee HPMC wuxuu si toos ah u saameeyaa viscosity ee xalkeeda aqueous. HPMC oo miisaankeedu sarreeyo waxay leedahay silsilado molecular oo dheer waxayna samayn kartaa qaab dhismeedka shabakad saddex-geesood ah oo aad u adag oo ku jira xalka aqueous, taasoo keentay in viscosity sareeyo. Taa beddelkeeda, HPMC oo leh miisaan kelliyeed hoose ayaa leh qaab-dhismeedka shabakad dabacsan iyo mawqif hoose oo ay ugu wacan tahay silsiladaha molecular ee gaaban. Sidaa darteed, marka la codsanayo, waxaa aad muhiim u ah in la doorto HPMC oo leh miisaan kelli ah oo ku habboon si loo gaaro saameynta ugu habboon ee viscosity.
(3) Saamaynta heerkulka
Heerkulka waa arrin muhiim ah oo saameynaysa viscosity ee xalka aqueous HPMC. Marka heerkulku kordho, dhaqdhaqaaqa molecules-ka biyuhu wuu sii xoogaysanayaa, viscosity ee xalka inta badan wuu yaraadaa. Tani waa sababta oo ah marka heerkulku kor u kaco, xorriyadda silsiladda molecular ee HPMC ayaa kordheysa iyo isdhexgalka ka dhexeeya molecules, taas oo yareyneysa viscosity ee xalka. Si kastaba ha ahaatee, jawaabta HPMC ee dufcadaha ama noocyada kala duwan ee heerkulku sidoo kale way kala duwanaan kartaa, markaa xaaladaha heerkulka ayaa loo baahan yahay in lagu hagaajiyo iyadoo loo eegayo shuruudaha codsiga gaarka ah.
(4) Saamaynta qiimaha pH
HPMC lafteedu waa iskudhis aan ionic ahayn, iyo viscosity ee xalkeeda aqueous ayaa xasaasi u ah isbeddelada pH. In kasta oo HPMC ay ku muujiso sifooyin viskosity ah oo deggan jawi aashito ah ama dhexdhexaad ah, milanka iyo mawqifka HPMC waxa ay saamayn doontaa deegaan aad u acidic ama alkaliin ah. Tusaale ahaan, marka la eego aashitada xooggan ama xaaladaha alkaline ee xooggan, molecules-yada HPMC ayaa laga yaabaa inay qayb ahaan hoos u dhacaan, si ay u yareeyaan viscosity ee xalkeeda aqueous.
3. Falanqaynta Rheological ee sifooyinka viscosity ee xal aqueous HPMC
Dabeecadda rheological ee xal aqueous HPMC sida caadiga ah waxay muujinaysaa sifooyin dheecaan aan Newtonian, taas oo macnaheedu yahay in ay viscosity ma aha oo kaliya la xidhiidha arrimaha sida diiradda xal iyo miisaanka kelli, laakiin sidoo kale in heerka xiirto. Guud ahaan, marka la eego heerarka hoose ee xiirid, xalalka aqueous ee HPMC wuxuu muujinayaa viscosity sare, halka marka heerka xiiridu uu kordho, mawduucu hoos u dhaco. Dabeecaddan waxa loo yaqaan "xiirid xiirid" ama "dhoobo xiiran" waxayna aad muhiim ugu tahay codsiyo badan oo la taaban karo. Tusaale ahaan, dhinacyada dahaarka, diyaarinta dawooyinka, diyaarinta cuntada, iwm., sifooyinka khafiifinta xiirid ee HPMC waxay xaqiijin kartaa in viscosity sare lagu hayo inta lagu jiro codsiyada xawaaraha hoose, iyo waxa ay si fudud u qulquli karaa hoos xaaladaha xiirid-xawaaraha sare.
4. Arrimaha kale ee saameeya viscosity ee xal aqueous HPMC
(1) Saamaynta milixda
Ku darida milixdu (sida chloride sodium) waxay kordhin kartaa viscosity ee xalka aqueous HPMC. Tani waa sababta oo ah milixdu waxay kor u qaadi kartaa isdhexgalka ka dhexeeya molecules iyadoo bedelaysa xoogga ionic ee xalka, si molecules HPMC ay u sameeyaan qaab dhismeed shabakadeed oo cufan, taas oo kordhinaysa viscosity. Si kastaba ha ahaatee, saamaynta nooca milixda iyo feejignaanta ee viscosity sidoo kale waxay u baahan tahay in la hagaajiyo iyadoo loo eegayo duruufo gaar ah.
(2) Saamaynta waxyaabaha kale ee lagu daro
Ku darida waxyaabaha kale ee lagu daro (sida surfactants, polymers, iwm.) ee HPMC xal aqueous waxay sidoo kale saameyn doontaa viscosity. Tusaale ahaan, surfactants ayaa laga yaabaa inay yareeyaan viscosity ee HPMC, gaar ahaan marka diirada surfactant waa sare. Intaa waxaa dheer, polymers ama qaybo gaar ah ayaa sidoo kale la falgali kara HPMC waxayna bedeli karaan sifooyinka rheological ee xalkeeda.
Tilmaamaha viscosity eehydroxypropyl methylcellulose xal aqueous waxaa saameeya arrimo badan, oo ay ku jiraan diiradda, miisaanka kelli, heerkulka, qiimaha pH, iwm HPMC aqueous xal sida caadiga ah soo bandhigaa guryaha rheological non-Newtonian, waxa uu leeyahay dhumuc wanaagsan iyo dhogorta guryaha khafiifinta, oo waxaa si ballaaran loo isticmaalaa in beeraha warshadaha iyo daawooyinka kala duwan. Fahamka iyo maaraynta sifooyinkan viscosity waxay gacan ka geysan doontaa wanaajinta isticmaalka HPMC ee codsiyada kala duwan. Codsiyada la taaban karo, nooca HPMC ee ku habboon iyo xaaladaha habka waa in lagu doortaa iyadoo loo eegayo baahiyo gaar ah si loo helo viscosity habboon iyo sifooyinka rheological.
Waqtiga boostada: Mar-01-2025