Cellulose yog lub ntuj tsim ntau tshaj plaws nyob rau hauv cov xwm. Nws yog linear polymer compound txuas los ntawm D-glucose los ntawm β-(1-4) glycosidic bonds. Cov degree ntawm polymerization ntawm cellulose tuaj yeem ncav cuag 18,000, thiab qhov hnyav molecular tuaj yeem ncav cuag ntau lab.
Cellulose tuaj yeem tsim los ntawm cov ntaub ntoo los yog paj rwb, uas nws tus kheej tsis soluble hauv dej, tab sis nws muaj zog nrog alkali, etherified nrog methylene chloride thiab propylene oxide, ntxuav nrog dej, thiab qhuav kom tau dej-soluble methyl cellulose (MC) thiab hydroxypropyl methylcellulose (HPMC), uas yog, methoxy thiab hydroxypropoxy yog siv los hloov cov hydroxyl pawg ntawm C2, C3 thiab C6 txoj haujlwm ntawm cov piam thaj los ua cov nonionic cellulose ethers.
Methyl cellulose yog ib qho ntxhiab tsw, dawb mus rau creamy dawb hmoov zoo nyob rau hauv tsos, thiab pH ntawm cov tshuaj yog nyob nruab nrab ntawm 5-8.
Cov ntsiab lus methoxyl ntawm methylcellulose siv los ua cov khoom noj ntxiv yog feem ntau ntawm 25% thiab 33%, qhov sib txuas ntawm kev hloov pauv yog 17-2.2, thiab qhov theoretical degree ntawm kev hloov pauv yog nyob nruab nrab ntawm 0-3.
Raws li cov khoom noj ntxiv, cov ntsiab lus methoxyl ntawm hydroxypropyl methylcellulose feem ntau yog nyob nruab nrab ntawm 19% thiab 30%, thiab cov ntsiab lus hydroxypropyl feem ntau yog nyob nruab nrab ntawm 3% thiab 12%.
Cov yam ntxwv ua
thermoreversible gel
Methylcellulose/Hydroxypropylmethylcellulose muaj thermoreversible gelling zog.
Methyl cellulose / hydroxypropyl methyl cellulose yuav tsum tau yaj hauv dej txias lossis dej kub ib txwm. Thaum lub aqueous tov yog rhuab, lub viscosity yuav txo qis, thiab gelation yuav tshwm sim thaum nws ncav cuag ib tug tej yam kub thiab txias. Lub sijhawm no, methyl cellulose / hydroxypropyl methyl cellulose Lub pob tshab kua ntawm propyl methylcellulose pib tig mus rau hauv opaque milky dawb, thiab pom meej viscosity nce sai.
Qhov kub no hu ua thermal gel pib kub. Raws li cov gel txias, qhov pom tseeb viscosity poob sai. Thaum kawg, qhov viscosity nkhaus thaum txias yog ua raws li qhov pib cua sov viscosity nkhaus, cov gel hloov mus rau hauv cov tshuaj, cov tshuaj hloov mus rau hauv ib lub gel thaum rhuab, thiab cov txheej txheem ntawm tig rov qab mus rau hauv ib qho kev daws tom qab txias yog reversible thiab rov ua dua.
Hydroxypropyl methylcellulose muaj cov thermal gelation pib kub dua li methylcellulose thiab qis zog gel.
Pkev ua haujlwm
1. Zaj duab xis-forming zog
Cov yeeb yaj kiab tsim los ntawm methylcellulose / hydroxypropylmethylcellulose lossis cov yeeb yaj kiab uas muaj ob qho tib si tuaj yeem tiv thaiv cov roj tsiv teb tsaws thiab dej poob, yog li ua kom muaj kev ruaj ntseg ntawm cov khoom noj khoom haus.
2. Emulsifying zog
Methylcellulose/Hydroxypropylmethylcellulose tuaj yeem txo qhov nro thiab txo cov rog rog kom zoo dua emulsion stability.
3. Kev tswj tsis tau dej
Methylcellulose/Hydroxypropylmethylcellulose tuaj yeem tswj cov dej noo ntawm cov khoom noj los ntawm khov mus rau qhov kub thiab txias, thiab tuaj yeem txo qhov kev puas tsuaj, dej khov crystallization thiab kev ntxhib los mos ntawm cov khoom noj los ntawm cov tub yees.
4. Adhesive kev ua tau zoo
Methylcellulose/Hydroxypropylmethylcellulose yog siv nyob rau hauv cov nyiaj tau zoo los tsim kom muaj kev pom zoo ntawm daim ntawv cog lus lub zog thaum tswj cov dej noo thiab tsw tso tawm.
5. Kev ua haujlwm hydration qeeb
Kev siv cov methylcellulose / hydroxypropylmethylcellulose tuaj yeem txo cov viscosity ntawm cov khoom noj thaum lub sij hawm ua thermal, yog li txhim kho kev ua haujlwm zoo. Txo boiler thiab cov cuab yeej fouling, ua kom cov txheej txheem lub sij hawm, txhim kho thermal efficiency, thiab txo qhov tso nyiaj.
6. Thickening kev ua tau zoo
Methylcellulose/Hydroxypropylmethylcellulose tuaj yeem siv ua ke nrog cov hmoov txhuv nplej siab los tsim cov nyhuv synergistic, uas tuaj yeem ua kom cov viscosity zoo heev txawm nyob rau theem qis heev.
7. Cov tshuaj yog ruaj khov nyob rau hauv acidic thiab cawv
Methylcellulose/Hydroxypropylmethylcellulose cov kev daws teeb meem yog ruaj khov mus rau pH 3 thiab muaj kev ruaj ntseg zoo hauv cov tshuaj uas muaj cawv.
Kev siv methyl cellulose hauv cov khoom noj
Methyl cellulose yog ib hom non-ionic cellulose ether tsim los ntawm kev siv natural cellulose li raw khoom thiab hloov cov hydroxyl pawg ntawm cov anhydrous qabzib unit hauv cellulose nrog methoxy pawg. Nws muaj dej tuav, thickening, emulsification, zaj duab xis tsim, adaptability dav pH ntau yam thiab deg kev ua si thiab lwm yam dej num.
Nws qhov tshwj xeeb tshaj plaws yog thermally reversible gelation, uas yog, nws cov tshuaj aqueous tsim cov gel thaum rhuab, thiab tig rov qab rau cov tshuaj thaum txias. Nws yog dav siv hauv cov khoom noj ci, khoom noj kib, khoom qab zib, kua ntses, kua zaub, dej haus, thiab essences. thiab khoom qab zib.
Lub super gel hauv methyl cellulose muaj lub zog gel ntau dua li peb zaug ntawm cov pa methyl cellulose thermal gels, thiab muaj cov nplaum nplaum muaj zog, dej tuav thiab cov khoom tuav zoo.
Nws tso cai rau cov khoom noj rov ua dua kom khaws lawv cov kev xav tau ruaj khov thiab muaj kua hauv lub qhov ncauj ob lub sijhawm thiab rau lub sijhawm ntev dua tom qab rov ua dua. Cov ntawv thov ib txwm yog cov khoom noj khov khov sai, cov khoom noj tsis noj nqaij, rov tsim cov nqaij, ntses thiab nqaij nruab deg thiab cov hnyuv ntxwm rog tsawg.
Post lub sij hawm: Dec-12-2022