Methyl Cellulose (MC) Molecular formula \[C6H7O2(OH)3-h(OCH3)n1] x Cotton yakanatswa inobatwa nealkali, uye methyl chloride inoshandiswa seetherification agent. Mushure mekuita kwakatevedzana, kurapwa kwe cellulose ether kunoitwa. Kazhinji, dhigirii rekutsiva i1.6 ~ 2.0, uye dhigirii rekutsiva rakasiyana. Iyo ndeye isiri-ionic cellulose ether.
1. Methylcellulose inonyungudika mumvura inotonhora, mvura inopisa ichasangana nematambudziko, uye pH yakasiyana-siyana yemushonga wemvura yakanyatsogadzikana pakati pe3/12. Starch, guar gum uye mamwe akawanda ma surfactants anowirirana. Gelation inoitika kana tembiricha yasvika tembiricha yegelation.
Kuchengetwa kwemvura kwemethylcellulose kunoenderana nehuwandu hwayo hwakawedzerwa, viscosity, particle fineness uye dissolution rate. Kazhinji yakawedzera, diki, yakakwira viscosity, yakakwira mvura yekuchengetedza. Pakati pavo, kuchengetwa kwemvura kune simba guru, uye viscosity level haina kuenzana zvakananga nekuchengetedza mvura. Mwero wekunyunguduka unonyanya kuenderana nehuwandu hwekugadziriswa kwepasi kwezvikamu zve cellulose uye kunaka kwezvimedu. Pakati pema cellulose ethers ari pamusoro, methyl cellulose uye hydroxypropyl methyl cellulose vane kuchengetwa kwemvura kwakakwira.
Kuchinja kwekushisa kunogona kukanganisa zvakanyanya kuchengetwa kwemvura yemethyl cellulose. - Kuwedzera kwekushisa, kunowedzera kuchengetwa kwemvura. Kana tembiricha yevhu ichipfuura 40 ° C, kuchengetwa kwemvura kwemethyl cellulose kuchaderedzwa zvakanyanya, kunokanganisa zvakanyanya kuvakwa kwedhaka.
Methylcellulose ine mhedzisiro yakakosha pakushanda uye kunamatira kwedhaka. “Kunamira” pano kunoreva kunamira pakati pemudziyo wekushandisa wemushandi nemadziro emadziro, ndiko kuti, kushomeka kwevhu. Viscosity, simba rekuveura dhaka, uye simba rinodiwa nevashandi vari kushandiswa zvakare rakakura kwazvo, uye kuvaka dhaka hakuna kunaka. Methylcellulose yakanamatira pamwero wepakati mune cellulose ether zvigadzirwa.
2. Hydroxypropyl methylcellulose (HPMC) [C 6 H 7 O 2 (OH) 3-mn (OCH 3 ) m, OCH 2 CH (OH) CH 3] n]] hydroxypropyl methyl cellulose Mumakore achangopfuura, marudzi e cellulose ane yakawedzera nokukurumidza. Iyo isiri-ionic cellulose yakasanganiswa ether inogadzirwa neyakatevedzana maitiro mushure me alkalization yakanatswa donje alkali, umo propylene oxide uye methyl chloride inoshandiswa se etherification agents. Dhigirii rekutsiva rinowanzo 1.2/2.0. Zvimiro zvayo zvinosiyana zvichienderana nereshiyo yemethoxyl yemukati uye hydroxypropyl yemukati.
1. Hydroxypropyl methylcellulose yakakamurwa kuva inopisa-yakanyunguduka mhando uye pakarepo mhando. Kupisa kwayo kwegelation mumvura inopisa kwakanyanya kudarika iyo yemethylcellulose. Inoratidzawo kuvandudzwa kukuru pamusoro pemethylcellulose kana yakanyungudutswa mumvura inotonhora.
Iyo viscosity yehydroxypropyl methylcellulose inoenderana nehuremu hwemamorekuru, uye huremu hwemamorekuru hwakakwira. Kupisa kunokanganisawo viscosity yayo, sezvo tembiricha inowedzera, viscosity inoderera. Nekudaro, pesvedzero yekushisa pane viscosity yakaderera pane iyo yemethyl cellulose. Mhinduro ndeyekuchengetedza yakagadzikana pakamuri yekupisa.
3. Kuchengetwa kwemvura yehydroxypropyl methylcellulose kunoenderana nehuwandu hwayo hwekuwedzera, viscosity, nezvimwewo, uye chiyero chekuchengetedza mvura chechiyero chakafanana chakakwirira kudarika chemethyl cellulose.
4. Hydroxypropyl methylcellulose yakagadzikana kune acid uye alkali, uye mhinduro yayo yemvura yakanyatsogadzikana mu pH ye2 / 12. Kuita kwecaustic soda uye lime mvura haina simba rakawanda, asi alkali inogona kukurumidza kuparara kwayo, uye viscosity inowedzera. Hydroxypropyl methylcellulose yakagadzikana kune yakajairwa munyu, asi kana kusanganiswa kwemunyu munyu kwakakwira, viscosity yehydroxypropyl methylcellulose mhinduro inowedzera kuwedzera.
Hydroxypropyl methylcellulose inogona kusanganiswa nemvura-inonyungudika polima kuti iite yunifomu, yakakwirira-viscosity mhinduro. Zvakadai se polyvinyl doro, starch ether, muriwo gum, nezvimwe.
Hydroxypropyl methylcellulose ine nani enzyme kuramba kupfuura methylcellulose, mukana we enzymatic degradation yemhinduro yayo yakaderera pane iyo yemethylcellulose, uye kunamatira kwehydroxypropylmethylcellulose pakuvaka dhaka kwakakwira kupfuura iyo yemethylcellulose. base cellulose.
Yetatu, hydroxyethyl cellulose (HEC) inogadzirwa kubva kudonje rakanatswa rinobatwa nealkali, pamberi peacetone, uye ethylene oxide se etherification agent. Dhigirii rayo rekutsiva kazhinji 1.5 / 2.0. Iyo ine yakasimba hydrophilicity uye iri nyore kutora unyoro.
1. Hydroxyethyl cellulose inonyungudika mumvura inotonhora, asi zvakaoma kunyunguduka mumvura inopisa. Mhinduro yacho yakagadzikana pakupisa kwepamusoro uye haina gel properties. Inogona kushandiswa kwenguva yakareba mumatope ekupisa kwepamusoro, asi kuchengetedza kwayo mvura kwakaderera pane iyo methyl cellulose.
2. Hydroxyethyl cellulose yakagadzikana kune general acid uye alkali. Alkali inomhanyisa kupera kwayo, uye viscosity yayo inowedzera zvishoma. Kupararira kwayo mumvura kwakashata zvishoma kupfuura iyo yemethyl cellulose uye hydroxypropyl methyl cellulose.
3. Hydroxyethyl cellulose ine basa rakanaka rekudzivirira-kurembera padhaka, asi kwenguva yakareba, imwe hydroxyethyl cellulose inogadzirwa mudzimba ine basa rakaderera zvikuru kupfuura methyl cellulose nekuda kwehuwandu hwemvura yakawanda uye yakakwirira madota.
4. Carboxymethyl cellulose (CMC) \ [C6H7O2 (OH) 2och2COONa] (donje, etc.) yefiber yakasikwa inobatwa nealkali, uye sodium chloroacetate inoshandiswa se etherification agent, mushure mekutevedzana kwemaitiro ekurapa, inogadzirwa ionic. cellulose ether. Dhigirii rekutsiva rinowanzo 0.4 / 1.4, uye dhigirii rekutsinhanisa rine simba guru pakuita.
Carboxymethyl cellulose ine yakakwira hygroscopicity, uye yakajairwa kuchengetedza mamiriro ane yakawanda mvura.
2. Carboxymethyl cellulose aqueous solution haibudisi gel, viscosity inodzikira kana tembiricha yakwira, uye viscosity haidzoreki kana tembiricha yadarika 50°C.
Kugadzikana kwayo kunokanganisa zvakanyanya pH. Inowanzo shandiswa gypsum mortar, kwete yesamende dhaka. Muchiitiko chepamusoro alkalinity, icharasikirwa neviscosity yayo.
Kuchengetwa kwayo kwemvura kwakadzikira zvakanyanya kupfuura kwemethyl cellulose. Gypsum dhaka ine retading mhedzisiro, kuderedza simba. Asi mutengo wecarboxymethyl cellulose wakaderera zvakanyanya pane wemethyl cellulose.
Nguva yekutumira: Jan-13-2023