Awọn ohun-ini ti hydroxypropyl methylcellulose

Hydroxypropyl methylcellulose HPMC jẹ iru ti kii-ionic cellulose adalu ether.Ko dabi ionic methyl carboxymethyl cellulose adalu ether, ko fesi pẹlu eru awọn irin.Nitori awọn ipin oriṣiriṣi ti akoonu methoxyl ati akoonu hydroxypropyl ninu hydroxypropyl methylcellulose ati awọn viscosities oriṣiriṣi, ọpọlọpọ awọn oriṣiriṣi wa pẹlu awọn ohun-ini oriṣiriṣi, fun apẹẹrẹ, akoonu methoxyl giga ati akoonu hydroxypropyl kekere Išẹ rẹ sunmọ ti methyl cellulose, lakoko ti ti kekere Akoonu methoxyl ati akoonu hydroxypropyl giga wa nitosi ti hydroxypropyl methyl cellulose.Bibẹẹkọ, ni oriṣiriṣi kọọkan, botilẹjẹpe iye kekere ti ẹgbẹ hydroxypropyl tabi iye kekere ti ẹgbẹ methoxyl wa ninu, awọn iyatọ nla wa ninu solubility ni awọn olomi Organic tabi iwọn otutu flocculation ni awọn ojutu olomi.

(1) Awọn ohun-ini solubility ti hydroxypropyl methylcellulose

① Solubility ti hydroxypropyl methylcellulose ninu omi Hydroxypropyl methylcellulose jẹ kosi iru methylcellulose ti a ṣe atunṣe nipasẹ propylene oxide (methoxypropylene), nitorina o tun ni awọn ohun-ini kanna bi methyl cellulose Cellulose ni awọn abuda ti o jọra ti omi tutu solubility ati omi gbona insolubility.Sibẹsibẹ, nitori ẹgbẹ hydroxypropyl ti a ṣe atunṣe, iwọn otutu gelation rẹ ninu omi gbona ga pupọ ju ti methyl cellulose lọ.Fun apẹẹrẹ, iki ti hydroxypropyl methylcellulose aqueous ojutu pẹlu 2% methoxy akoonu aropo ìyí DS=0.73 ati hydroxypropyl akoonu MS=0.46 jẹ 500 mpa·s ni 20°C, ati awọn oniwe-jeli otutu O le de ọdọ sunmọ 100°C, nigba ti methyl cellulose ni iwọn otutu kanna jẹ nipa 55 ° C.Bi fun isokan ninu omi, o tun ti ni ilọsiwaju pupọ.Fun apẹẹrẹ, awọn pulverized hydroxypropyl methylcellulose (granular apẹrẹ 0.2 ~ 0.5mm ni 20 ° C pẹlu kan 4% olomi ojutu iki ti 2pa•s le ṣee ra ni yara otutu, o jẹ awọn iṣọrọ tiotuka ninu omi lai itutu.

② Solubility ti hydroxypropyl methylcellulose ninu awọn nkan ti o ni nkan ti o ni nkan ti o ni nkan ti o wa ni erupẹ ti o ni agbara ti hydroxypropyl.Fun awọn ọja ti o wa loke 2.1, hydroxypropyl methylcellulose giga-viscosity ti o ni hydroxypropyl MS=1.5 ~ 1.8 ati methoxy DS=0.2 ~ 1.0, pẹlu iwọn aropo lapapọ loke 1.8, jẹ tiotuka ni methanol anhydrous ati ethanol awọn ojutu Alabọde, ati thermoplastic ati omi-soluble .O tun jẹ tiotuka ninu awọn hydrocarbons chlorinated gẹgẹbi methylene kiloraidi ati chloroform, ati awọn nkan ti o nfo Organic gẹgẹbi acetone, isopropanol ati ọti diacetone.Solubility rẹ ni awọn nkan ti o nfo Organic dara ju omi solubility lọ.

(2) Awọn okunfa ti o ni ipa lori viscosity ti hydroxypropyl methylcellulose Ipinnu viscosity boṣewa ti hydroxypropyl methylcellulose jẹ kanna bi awọn ethers cellulose miiran, ati pe a wọn ni 20 ° C pẹlu 2% ojutu olomi gẹgẹbi idiwọn.Igi ti ọja kanna pọ si pẹlu ilosoke ti ifọkansi.Fun awọn ọja pẹlu awọn iwuwo molikula oriṣiriṣi ni ifọkansi kanna, ọja pẹlu iwuwo molikula nla ni iki ti o ga julọ.Ibasepo rẹ pẹlu iwọn otutu jẹ iru si ti methyl cellulose.Nigbati iwọn otutu ba ga, iki bẹrẹ lati dinku, ṣugbọn nigbati o ba de iwọn otutu kan.

iki lojiji dide ati gelation waye.Awọn iwọn otutu jeli ti awọn ọja iki kekere jẹ ti o ga julọ.ga.Ojuami gel rẹ kii ṣe ibatan si iki ti ether nikan, ṣugbọn tun ni ibatan si ipin tiwqn ti ẹgbẹ methoxyl ati ẹgbẹ hydroxypropyl ni ether ati iwọn iwọn aropo lapapọ.O gbọdọ ṣe akiyesi pe hydroxypropyl methylcellulose tun jẹ pseudoplastic, ati pe ojutu rẹ jẹ iduroṣinṣin ni iwọn otutu yara laisi ibajẹ eyikeyi ninu iki ayafi fun iṣeeṣe ibajẹ enzymatic.

(3) Ifarada iyọ ti hydroxypropyl methylcellulose Niwọn igba ti hydroxypropyl methylcellulose jẹ ether ti kii-ionic, kii ṣe ionize ninu awọn media omi, ko dabi awọn ethers cellulose ionic miiran, Fun apẹẹrẹ, carboxymethyl cellulose ṣe atunṣe pẹlu awọn ions irin ti o wuwo ati pe o jade ni ojutu.Awọn iyọ gbogbogbo gẹgẹbi kiloraidi, bromide, fosifeti, iyọ, ati bẹbẹ lọ kii yoo ṣaju nigbati a ba fi kun si ojutu olomi rẹ.Sibẹsibẹ, afikun iyọ ni diẹ ninu ipa lori iwọn otutu flocculation ti ojutu olomi rẹ.Nigbati ifọkansi iyọ ba pọ si, iwọn otutu gel dinku.Nigbati ifọkansi iyọ ba wa ni isalẹ aaye flocculation, iki ti ojutu duro lati pọ si.Nitorina, iye iyọ kan ti wa ni afikun., ni ohun elo, o le ṣe aṣeyọri ipa ti o nipọn diẹ sii ni ọrọ-aje.Nitorina, ni diẹ ninu awọn ohun elo, o dara lati lo adalu cellulose ether ati iyọ ju iṣeduro ti o ga julọ ti ojutu ether lati ṣe aṣeyọri ipa ti o nipọn.

(4) Hydroxypropyl methylcellulose acid ati alkali resistance Hydroxypropyl methylcellulose jẹ iduroṣinṣin gbogbogbo si acids ati alkalis, ati pe ko ni ipa ni iwọn pH 2 ~ 12.O le koju iye kan ti Awọn acids Imọlẹ, gẹgẹbi formic acid, acetic acid, citric acid, succinic acid, phosphoric acid, boric acid, bbl Ṣugbọn acid ti o ni idojukọ ni ipa ti idinku iki.Alkalis gẹgẹbi omi onisuga caustic, potash caustic ati omi orombo wewe ko ni ipa lori rẹ, ṣugbọn wọn le mu iki ti ojutu pọ si diẹ, ati lẹhinna dinku laiyara.

(5) Aiṣedeede ti hydroxypropyl methylcellulose ojutu Hydroxypropyl methylcellulose ni a le dapọ pẹlu awọn agbo ogun polima ti omi-tiotuka lati di aṣọ aṣọ ati ojutu sihin pẹlu iki ti o ga julọ.Awọn agbo ogun polymer wọnyi pẹlu polyethylene glycol, polyvinyl acetate, polysilicon, polymethylvinylsiloxane, hydroxyethyl cellulose, ati methyl cellulose.Adayeba ga molikula agbo bi gomu arabic, eṣú ewa gomu, karaya gomu, bbl tun ni ibamu ti o dara pẹlu ojutu rẹ.Hydroxypropyl methylcellulose tun le dapọ pẹlu mannitol ester tabi sorbitol ester ti stearic acid tabi palmitic acid, ati pe o tun le dapọ pẹlu glycerin, sorbitol ati mannitol, ati pe awọn agbo ogun wọnyi le ṣee lo bi hydroxypropyl methylcellulose Plasticizer fun cellulose.

(6) Awọn ethers cellulose ti omi ti ko ni iyọdajẹ ti hydroxypropyl methylcellulose le jẹ asopọ agbelebu pẹlu awọn aldehydes lori aaye, ki awọn ethers ti o ni omi ti o ni omi ti wa ni ipilẹ ni ojutu ati ki o di insoluble ninu omi.Awọn aldehydes ti o jẹ ki hydroxypropyl methylcellulose insoluble pẹlu formaldehyde, glioxal, succinic aldehyde, adipaldehyde, ati bẹbẹ lọ Nigbati o ba nlo formaldehyde, akiyesi pataki yẹ ki o san si iye pH ti ojutu, laarin eyiti glioxal ṣe atunṣe ni kiakia, nitorina glioxal ni a lo nigbagbogbo gẹgẹbi ọna asopọ agbelebu. oluranlowo ni ise gbóògì.Iwọn iru iru oluranlowo ọna asopọ agbelebu ni ojutu 0.2% ~ 10% ti iwọn ether, pelu 7% ~ 10%, fun apẹẹrẹ, 3.3% ~ 6% ti glioxal ni o dara julọ.Ni gbogbogbo, itọju naa

iwọn otutu jẹ 0 ~ 30 ℃, ati akoko jẹ 1 ~ 120min.Idahun sisopọ agbelebu nilo lati ṣe labẹ awọn ipo ekikan.Ni gbogbogbo, ojutu ni akọkọ ṣafikun pẹlu inorganic lagbara acid tabi Organic carboxylic acid lati ṣatunṣe pH ti ojutu si nipa 2 ~ 6, ni pataki laarin 4 ~ 6, ati lẹhinna ṣafikun awọn aldehydes lati ṣe iṣesi ọna asopọ agbelebu.Acid ti a lo ni hydrochloric acid, sulfuric acid, phosphoric acid, formic acid, acetic acid, hydroxyacetic acid, succinic acid tabi citric acid bbl, ninu eyiti o ni imọran pẹlu formic acid tabi acetic acid, ati formic acid jẹ aipe.Acid ati aldehyde tun le ṣe afikun ni igbakanna lati gba ojutu laaye lati farada iṣesi ọna asopọ agbelebu laarin iwọn pH ti o fẹ.Idahun yii ni a lo nigbagbogbo ni ilana itọju ikẹhin ni ilana igbaradi ti awọn ethers cellulose.Lẹhin ti ether cellulose jẹ insoluble, o rọrun lati lo

20 ~ 25 ℃ omi fun fifọ ati ìwẹnumọ.Nigbati ọja ba wa ni lilo, awọn oludoti ipilẹ le ṣe afikun si ojutu ọja lati ṣatunṣe pH ti ojutu lati jẹ ipilẹ, ati pe ọja naa yoo tu ni ojutu ni iyara.Ọna yii tun wulo fun itọju fiimu naa lẹhin ti a ti ṣe ojutu ether cellulose sinu fiimu kan lati jẹ ki o jẹ fiimu ti a ko le yanju.

(7) Agbara enzymu ti hydroxypropyl methylcellulose jẹ awọn itọsẹ cellulose ni imọ-jinlẹ, gẹgẹ bi ẹgbẹ anhydroglucose kọọkan, ti ẹgbẹ aropo ti o ni ṣinṣin, ko rọrun lati ni akoran nipasẹ awọn microorganisms, ṣugbọn ni otitọ ọja ti pari Nigbati iye aropo ba kọja 1, yoo tun jẹ ibajẹ nipasẹ awọn enzymu, eyiti o tumọ si pe iwọn iyipada ti ẹgbẹ kọọkan lori pq cellulose ko ni aṣọ ti o to, ati pe awọn microorganisms le fa fifalẹ lori ẹgbẹ anhydroglucose ti a ko rọpo lati dagba awọn suga, bi awọn ounjẹ fun awọn microorganisms lati fa.Nitorina, ti o ba ti awọn ìyí ti etherification fidipo ti cellulose posi, awọn resistance to enzymatic ogbara ti cellulose ether yoo tun mu.Gẹgẹbi awọn ijabọ, labẹ awọn ipo iṣakoso, awọn abajade hydrolysis ti awọn ensaemusi, iyọkuro ti hydroxypropyl methylcellulose (DS=1.9) jẹ 13.2%, methylcellulose (DS=1.83) jẹ 7.3%, methylcellulose (DS=1.66) jẹ 3.8%, ati hydroxyethyl cellulose jẹ 1.7%.O le rii pe hydroxypropyl methylcellulose ni agbara egboogi-enzyme to lagbara.Nitorinaa, resistance henensiamu ti o dara julọ ti hydroxypropyl methylcellulose, ni idapo pẹlu itọka ti o dara, ti o nipọn ati awọn ohun-ini fiimu, ni a lo ninu awọn ohun elo emulsion omi, ati bẹbẹ lọ, ati ni gbogbogbo ko nilo lati ṣafikun awọn olutọju.Sibẹsibẹ, fun ibi ipamọ igba pipẹ ti ojutu tabi ibajẹ ti o ṣee ṣe lati ita, a le fi awọn ohun-ọṣọ ṣe afikun bi iṣọra, ati pe o le ṣe ipinnu ni ibamu si awọn ibeere ikẹhin ti ojutu.Phenylmercuric acetate ati manganese fluorosilicate jẹ awọn olutọju ti o munadoko, ṣugbọn gbogbo wọn ni Majele, akiyesi gbọdọ san si iṣẹ naa.Ni gbogbogbo, 1 ~ 5mg ti phenylmercury acetate le ṣe afikun si ojutu fun lita ti iwọn lilo.

(8) Iṣe ti fiimu hydroxypropyl methylcellulose Hydroxypropyl methylcellulose ni awọn ohun-ini iṣelọpọ fiimu ti o dara julọ.Ojutu olomi rẹ tabi ojutu olomi Organic jẹ ti a bo lori awo gilasi kan, ati pe o di alaini awọ ati sihin lẹhin gbigbe.Ati fiimu lile.O ni resistance ọrinrin to dara ati pe o wa ni ri to ni awọn iwọn otutu giga.Ti o ba jẹ pilasitik hygroscopic ti wa ni afikun, elongation ati irọrun rẹ le ni ilọsiwaju.Ni awọn ofin ti imudarasi irọrun, awọn ṣiṣu ṣiṣu bi glycerin ati sorbitol ni o dara julọ.Ni gbogbogbo, ifọkansi ojutu jẹ 2% ~ 3%, ati iye ṣiṣu jẹ 10% ~ 20% ti ether cellulose.Ti akoonu ti ṣiṣu ṣiṣu ba ga ju, idinku gbigbẹ colloidal yoo waye ni ọriniinitutu giga.Agbara fifẹ ti fiimu pẹlu

Plasticizer ti a ṣafikun tobi pupọ ju iyẹn lọ laisi pilasita, ati pe o pọ si pẹlu ilosoke ti iye ti a ṣafikun.Bi fun hygroscopicity ti fiimu naa, o tun pọ si pẹlu ilosoke ti iye ṣiṣu.