Hydroxypropyl methylcellulose HPMC jẹ iru ti kii-ionic cellulose adalu ether. Yatọ si ionic methyl carboxymethyl cellulose adalu ether, ko fesi pẹlu eru awọn irin. Nitori awọn ipin oriṣiriṣi ti akoonu methoxyl ati akoonu hydroxypropyl ni 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 iṣẹ ṣiṣe ti akoonu methoxy kekere ati akoonu hydroxypropyl giga sunmo ti hydroxypropyl methyl cellulose. Bibẹẹkọ, ni oriṣiriṣi kọọkan, botilẹjẹpe iye kekere ti ẹgbẹ hydroxypropyl tabi iye kekere ti ẹgbẹ methoxyl wa ninu, solubility ni awọn olomi Organic tabi iwọn otutu flocculation ni ojutu olomi yatọ pupọ.
1. 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 olomi ojutu pẹlu 2% methoxy akoonu aropo ìyí DS=0.73 ati hydroxypropyl akoonu MS=0.46 jẹ ọja ti 500 mpa?s ni 20°C, ati awọn oniwe-jeli otutu O le de ọdọ sunmo si 100° C, lakoko ti methyl cellulose ni iwọn otutu kanna jẹ nipa 55°C. Niti itusilẹ rẹ ninu omi, o tun ti ni ilọsiwaju pupọ. Fun apẹẹrẹ, awọn pulverized hydroxypropyl methylcellulose (ọja kan pẹlu kan patiku iwọn ti 0.2 ~ 0.5mm ati ki o kan 4% olomi ojutu iki ti 2pa?s ni 20 °C le ti wa ni ra ni Ni yara otutu, o jẹ awọn iṣọrọ tiotuka ninu omi lai itutu agbaiye. .
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 loke 2.1,giga-viscosity hydroxypropyl methylcelluloseti o ni hydroxypropyl MS=1.5~1.8 ati methoxy DS=0.2~1.0, pẹlu iwọn aropo lapapọ loke 1.8, jẹ tiotuka ninu kẹmika anhydrous ati awọn ojutu ethanol Alabọde, ati thermoplastic ati omi-tiotuka. 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 wa ni erupẹ Organic dara ju omi solubility lọ.
2. Awọn okunfa ti o ni ipa lori iki ti hydroxypropyl methylcellulose
Awọn Okunfa Ti nfa Iyika ti Hydroxypropyl Methyl Cellulose Ipinnu viscosity boṣewa ti hydroxypropyl methyl cellulose jẹ kanna bii ti awọn ethers cellulose miiran. O jẹ iwọn ni 20 ° C pẹlu 2% ojutu olomi bi boṣewa. 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 soke, iki bẹrẹ lati dinku, ṣugbọn nigbati o ba de iwọn otutu kan, iki yoo dide lojiji 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. Hydroxypropyl methylcellulose jẹ sooro si acid ati alkali
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 duro ni iye kan ti ina ina, 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.
4. Awọn miscibility ti hydroxypropyl methylcellulose
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.
5. Insolubilization ati omi solubility ti hydroxypropyl methylcellulose
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 omi-omi-omi wọnyi ti wa ni iponju ninu 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 jẹ 0.2% ~ 10% ti ether, pelu 7% ~ 10%, fun apẹẹrẹ, 3.3% ~ 6% ti glioxal ni o dara julọ. Iwọn otutu itọju gbogbogbo jẹ 0 ~ 30 ℃, ati pe 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 wẹ ati sọ di mimọ pẹlu omi ni 20 ~ 25 ° C. 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.
6. Enzyme resistance ti hydroxypropyl methylcellulose
Agbara enzymu ti hydroxypropyl methylcellulose jẹ awọn itọsẹ cellulose ni imọ-jinlẹ, gẹgẹbi ẹgbẹ kọọkan anhydroglucose, ti ẹgbẹ aropo ti o ni ṣinṣin, ko rọrun lati ni akoran nipasẹ awọn microorganisms, ṣugbọn ni otitọ ọja ti pari Nigbati iye iyipada ba kọja 1, o yoo tun ti wa ni degraded nipasẹ awọn ensaemusi, eyi ti o tumo si wipe awọn ìyí ti fidipo ti kọọkan ẹgbẹ lori cellulose pq ni ko aṣọ to, ati microorganisms le erode lori awọn aropo anhydroglucose ẹgbẹ lati dagba sugars , bi eroja fun 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.
7. Išẹ ti hydroxypropyl methylcellulose awo
Iṣiṣẹ 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 ti a fi kun pẹlu ṣiṣu ṣiṣu jẹ eyiti o tobi ju ti laisi afikun, ati pe o pọ si pẹlu ilosoke ti iye ti a fi kun, ati hygroscopicity ti fiimu naa tun pọ si pẹlu ilosoke iye ti plasticizer.
Akoko ifiweranṣẹ: Oṣu kejila-19-2022