Hydroxypropyl methyl cellulose HPMC yog ib qho non-ionic cellulose sib xyaw ether hauv ntau yam thiab ionic methyl carboxymethyl cellulose sib xyaw ether, nws tsis cuam tshuam nrog cov hlau hnyav. Ib qho oxygen radicals vim yog hydroxypropyl methyl cellulose cov ntsiab lus thiab qhov sib txawv ntawm hydroxypropyl cov ntsiab lus thiab viscosity, ua rau ntau yam sib txawv ntawm kev ua tau zoo, piv txwv li, cov ntsiab lus methoxyl siab thiab cov ntsiab lus qis ntawm hydroxypropyl ntau yam, nws cov kev ua tau zoo ze rau methyl cellulose thiab cov ntsiab lus methoxyl qis thiab cov ntsiab lus siab ntawm hydroxypropyl ntau yam, thiab nws cov kev ua tau zoo ze rau hydroxypropyl methyl cellulose tsim tawm. Tab sis hauv txhua hom, txawm hais tias tsuas muaj me me ntawm hydroxypropyl lossis me me ntawm methoxy, qhov solubility hauv cov organic solvents lossis flocculation kub hauv aqueous kua, muaj qhov sib txawv loj.
1, hydroxypropyl methyl cellulose solubility
Hydroxypropyl methyl cellulose hauv dej solubility ntawm hydroxypropyl methyl cellulose yog ib hom propylene oxide (methyl oxypropyl nplhaib) hloov kho methyl cellulose, yog li nws tseem muaj cov yam ntxwv zoo sib xws nrog methyl cellulose dej txias soluble thiab dej kub insoluble. Txawm li cas los xij, qhov kub gelation ntawm hloov kho hydroxy propyl yog siab dua li ntawm methyl cellulose hauv dej kub. Piv txwv li, qhov viscosity ntawm hydroxypropyl methylcellulose aqueous kua nrog 2% methoxy cov ntsiab lus DS = 0.73 thiab hydroxypropyl cov ntsiab lus MS = 0.46 yog 500 mpa ntawm 20 ℃. Qhov kub gel ntawm S cov khoom yog ze rau 100 ℃, thaum ntawm methyl cellulose ntawm tib qhov kub tsuas yog li 55 ℃. Raws li nws cov solubility hauv dej, kuj zoo heev, piv txwv li, tom qab tsoo ntawm hydroxypropyl methylcellulose (cov duab nplej 0.2 ~ 0.5 hli ntawm 20 ℃ 4% aqueous viscosity ntawm 2pA? S cov khoom tuaj yeem yaj tau yooj yim hauv dej yam tsis txias ntawm chav tsev kub.
(2) Hydroxypropyl methyl cellulose nyob rau hauv cov organic solvents solubility ntawm hydroxypropyl methyl cellulose nyob rau hauv cov organic solvents solubility, kuj zoo dua li methyl cellulose, methyl cellulose xav tau nyob rau hauv methoxy substitution degree ntawm 2.1 lossis ntau dua cov khoom, thiab muaj hydroxypropyl MS = 1.5 ~ 1.8 thiab methoxy DS = 0.2 ~ 1.0, High viscosity hydroxypropyl methyl cellulose nrog tag nrho cov degree hloov siab tshaj 1.8 yog soluble nyob rau hauv anhydrous methanol thiab ethanol daws, thiab muaj thermoplastic thiab dej solubility. Nws kuj yog soluble nyob rau hauv chlorinated hydrocarbons xws li dichloromethane thiab trichloromethane, thiab organic solvents xws li acetone, isopropyl cawv, thiab diacetone cawv. Nws solubility nyob rau hauv cov organic solvents yog superior rau dej solubility.
2, hydroxypropyl methyl cellulose viscosity ntawm cov yam ntxwv cuam tshuam
Cov yam ntxwv viscosity ntawm hydroxypropyl methylcellulose hydroxypropyl methylcellulose yog qhov kev txiav txim siab viscosity txheem, thiab lwm yam cellulose ether zoo ib yam, yog nyob rau ntawm 20 ℃ nrog 2% aqueous kua raws li qhov kev txiav txim siab txheem. Lub viscosity ntawm tib yam khoom, nrog rau kev nce ntawm concentration thiab nce, tib lub concentration ntawm cov khoom sib txawv molecular hnyav, molecular hnyav ntawm cov khoom yog viscosity siab. Nws txoj kev sib raug zoo nrog qhov kub thiab txias zoo ib yam li methyl cellulose. Thaum qhov kub nce, lub viscosity pib poob qis, tab sis thaum nws mus txog qee qhov kub, lub viscosity tam sim ntawd nce thiab gelation tshwm sim. Lub gelation kub ntawm cov khoom nrog viscosity qis yog siab dua li ntawm cov khoom nrog viscosity siab. Qib ntawm nws cov gel point, ntxiv rau qhov siab thiab qis viscosity ntawm ether, tab sis kuj nrog ether methoxy thiab hydroxypropyl pawg sib xyaw piv thiab tag nrho cov degree ntawm kev hloov pauv yog cuam tshuam. Nws yuav tsum tau sau tseg tias hydroxypropyl methylcellulose kuj yog pseudoplastic; nws cov kua ruaj khov thaum khaws cia ntawm chav tsev kub thiab tsis qhia txog kev puas tsuaj ntawm viscosity tsuas yog qhov ua tau ntawm enzymatic degradation.
3, hydroxypropyl methyl cellulose acid thiab alkaline tsis kam
Hydroxypropyl methylcellulose acid alkali hydroxypropyl methylcellulose acid thiab alkali, feem ntau ruaj khov, nyob rau hauv ph PH2 ~ 12 ntau yam tsis cuam tshuam, nws tuaj yeem tiv taus qee qhov ntawm cov kua qaub, xws li formic acid, acetic acid, citric acid, succinic acid, phosphoric acid, boric acid, thiab lwm yam. Tab sis cov kua qaub concentrated muaj cov nyhuv ntawm kev txo qhov viscosity. Alkali xws li caustic soda, caustic potassium thiab lime water tsis muaj cov nyhuv rau nws, tab sis cov nyhuv ntawm me ntsis nce qhov viscosity ntawm cov tshuaj yuav txo qis qeeb yav tom ntej.
4, hydroxypropyl methyl cellulose tuaj yeem sib xyaw ua ke
Cov tshuaj Hydroxypropyl methyl cellulose tuaj yeem sib xyaw nrog cov tshuaj polymer uas yaj tau hauv dej, thiab ua rau cov tshuaj pob tshab sib xws nrog viscosity siab dua. Cov tshuaj molecular siab no yog polyethylene glycol, polyvinyl acetate, polysilicone, polymethyl vinyl siloxane thiab hydroxyethyl cellulose thiab methyl cellulose, thiab lwm yam. Cov tshuaj polymer ntuj xws li gum Arabic, locust bean gum, thorn tree gum thiab lwm yam kuj muaj kev sib xyaw zoo nrog nws cov tshuaj. Hydroxypropyl methyl cellulose kuj tuaj yeem sib xyaw nrog stearic acid lossis palmitic acid mannitol ester lossis sorbitol ester, tab sis kuj nrog glycerol, sorbitol thiab mannitol, cov tshuaj no tuaj yeem siv ua hydroxypropyl methyl cellulose plasticizer.
5, hydroxypropyl methyl cellulose tsis yaj hauv dej soluble
Hydroxypropyl methyl cellulose insoluble water-soluble cellulose ether, tuaj yeem ua rau saum npoo sib txuas nrog aldehydes, thiab ua rau cov dej-soluble ether no precipitated hauv cov kua, ua rau insoluble hauv dej. Thiab ua rau hydroxypropyl methylcellulose insoluble aldehyde, formaldehyde, glyoxal, succinaldehyde, dialdehyde, thiab lwm yam, kev siv formaldehyde yuav tsum tau them sai sai rau tus nqi PH ntawm cov kua, uas ua rau glyoxal teb sai dua, yog li hauv kev tsim khoom lag luam feem ntau siv glyoxal ua tus neeg sawv cev sib txuas. Qhov ntau npaum li cas ntawm hom neeg sawv cev sib txuas hauv cov kua yog 0.2% ~ 10% ntawm ether pawg, qhov zoo tshaj plaws yog 7% ~ 10%, xws li kev siv glyoxal nrog 3.3% ~ 6% yog qhov tsim nyog tshaj plaws. Qhov kub thiab txias kho dav dav yog 0 ~ 30 ℃, lub sijhawm yog 1 ~ 120 feeb. Kev sib txuas sib txuas yuav tsum tau ua nyob rau hauv cov xwm txheej acidic. Feem ntau, cov kua qaub inorganic strong acid lossis organic carboxylic acid ntxiv rau hauv cov tshuaj kom kho qhov PH ntawm cov tshuaj kom txog li 2 ~ 6, zoo dua ntawm 4 ~ 6, thiab tom qab ntawd ntxiv cov aldehydes rau kev sib txuas lus. Cov kua qaub siv yog hydrochloric acid, sulfuric acid, phosphoric acid, formic acid, acetic acid, hydroxy acetic acid, succinic acid lossis citric acid, ntawm cov uas formic acid lossis acetic acid yog qhov zoo tshaj plaws, thaum formic acid yog qhov zoo tshaj plaws. Cov kua qaub thiab aldehydes kuj tseem tuaj yeem ntxiv tib lub sijhawm kom tso cai rau cov tshuaj kom sib txuas lus hauv qhov PH xav tau. Cov tshuaj no feem ntau siv rau hauv cov txheej txheem kawg ntawm cov txheej txheem npaj cellulose ether, yog li cellulose ether tsis yaj, yooj yim siv 20 ~ 25 ℃ dej los ntxuav thiab ntxuav. Thaum siv cov khoom, cov tshuaj alkaline tuaj yeem ntxiv rau hauv cov tshuaj ntawm cov khoom kom kho qhov PH ntawm cov tshuaj kom ua alkaline, thiab cov khoom yaj sai sai hauv cov tshuaj. Txoj kev no kuj tseem siv tau thaum cov kua cellulose ether siv los ua zaj duab xis thiab tom qab ntawd zaj duab xis raug kho kom ua zaj duab xis uas tsis yaj.
6, hydroxypropyl methyl cellulose tiv thaiv enzyme
Hydroxypropyl methyl cellulose enzyme tsis kam rau cellulose derivatives hauv kev xav, xws li txhua pawg anhydroglucose xws li muaj kev sib xyaw ua ke ntawm kev hloov pawg, kev puas tsuaj ntawm cov kab mob me me tsis tshua muaj kev kis kab mob, tab sis qhov tseeb cov khoom tiav los hloov tus nqi ntau dua 1, kuj los ntawm kev puas tsuaj ntawm enzyme, qhov no yog qhov piav qhia ntawm txhua pawg hauv cellulose saw hloov qib tsis sib xws, Microorganisms tuaj yeem puas tsuaj ze ntawm cov pab pawg tsis muaj dej qab zib los tsim cov suab thaj, uas tuaj yeem nqus tau los ntawm cov kab mob me me ua zaub mov. Yog li ntawd, yog tias qib hloov pauv etherification ntawm cellulose nce, qhov kev tiv thaiv ntawm cellulose ether rau kev puas tsuaj enzymatic yuav raug txhim kho. Nws tau tshaj tawm tias nyob rau hauv cov xwm txheej tswj hwm, qhov seem viscosity ntawm hydroxypropyl methyl cellulose (DS = 1.9), methyl cellulose (DS = 1.83), methyl cellulose (DS = 1.66), thiab hydroxyethyl cellulose (1.7%) yog 13.2%, 7.3%, 3.8%, thiab 1.7%, feem. Hydroxypropyl methyl cellulose muaj peev xwm tiv thaiv enzyme zoo heev. Yog li hydroxypropyl methylcellulose zoo heev tiv thaiv enzyme, ua ke nrog nws cov dispersion zoo, thickening thiab zaj duab xis tsim, siv rau hauv emulsion coatings, thiab lwm yam, feem ntau tsis tas yuav ntxiv preservatives. Txawm li cas los xij, txhawm rau tiv thaiv kev khaws cia ntev ntawm cov tshuaj lossis kev ua qias tuaj ntawm lub ntiaj teb sab nraud, cov preservatives tuaj yeem ntxiv, uas lawv xaiv tuaj yeem txiav txim siab raws li qhov yuav tsum tau ua tiav ntawm cov tshuaj. Phenylmercuric acetate thiab manganese fluosilicate yog cov preservatives zoo, tab sis lawv muaj tshuaj lom thiab yuav tsum tau ua tib zoo ua haujlwm. Feem ntau, 1 ~ 5mg phenylmercuric acetate tuaj yeem ntxiv rau txhua liter ntawm cov tshuaj.
7, hydroxypropyl methyl cellulose daim nyias nyias kev ua tau zoo
Hydroxypropyl methyl cellulose zaj duab xis ua tau zoo heev, nws cov kua dej los yog cov organic solvent kua, coated rau ntawm lub phaj iav, tom qab ziab ua xim tsis muaj xim, pob tshab thiab tawv zaj duab xis. Nws muaj kev tiv thaiv dej zoo thiab tseem khov kho ntawm qhov kub siab. Xws li ntxiv hygroscopic plasticizer, tuaj yeem txhim kho nws cov elongation thiab yooj ywm, los txhim kho flexure, glycerol thiab sorbitol thiab lwm yam plasticizer yog qhov tsim nyog tshaj plaws. Qhov concentration ntawm cov tshuaj dav dav yog 2% ~ 3%, qhov plasticizer dosage yog 10% ~ 20% ntawm cellulose ether. Yog tias cov ntsiab lus ntawm plasticizer yog exigent, qhov tshwm sim shrinkage ntawm colloid dehydration tuaj yeem tshwm sim hauv cov av noo siab. Lub zog tensile ntawm zaj duab xis ntxiv plasticizer yog ntau dua li qhov tsis ntxiv, thiab nce nrog kev nce ntawm qhov ntau ntxiv, rau qhov hygroscopicity ntawm zaj duab xis kuj nce nrog kev nce ntawm qhov ntau ntawm plasticizer.
Lub sijhawm tshaj tawm: Cuaj hlis-08-2022