Focus on Cellulose ethers

Hydroxypropyl methylcellulose HPMC?

Hydroxypropyl methylcellulose HPMC ne ba ionic cellulose gauraye ether a cikin daban-daban gauraye ethers tare da ionic methylcarboxymethylcellulose. Ba ya amsa da nauyi karafa. Bambance-bambance a cikin abun ciki na hydroxypropyl methylcellulose, hydroxypropyl methylcellulose, da hydroxypropyl abun ciki rabo da danko na oxygen free gene suna da mabanbanta iri-iri dangane da aiki. Misali, nau'ikan da ke da babban abun ciki na methoxyl da ƙarancin abun ciki na hydroxypropyl suna da ayyuka daban-daban. Kusa da methylcellulose da ƙananan abun ciki na methoxy. Idan aka kwatanta da nau'ikan da ke da babban abun ciki na hydroxypropyl, aikinsa yana kusa da na hydroxypropyl methylcellulose da aka samar. Duk da haka, ko da yake kowane iri-iri ya ƙunshi ƙaramin adadin hydroxypropyl ko ƙaramin ƙungiyar methoxy, akwai babban bambance-bambance a cikin solubility a cikin kaushi na kwayoyin halitta ko flocculation zafin jiki a cikin hanyoyin ruwa.

 

1. Solubility na hydroxypropyl methylcellulose

Solubility na hydroxypropyl methylcellulose a cikin ruwa Hydroxypropyl methylcellulose shi ne ainihin propylene oxide (methylhydroxypropyl zobe) modified methylcellulose, don haka har yanzu yana da iri daya kaddarorin kamar yadda methylcellulose Yana da irin wannan kaddarorin na zama mai narkewa a cikin ruwan sanyi amma insoluble a cikin ruwan zafi. Koyaya, gelling zafin jiki na modified hydroxypropyl a cikin ruwan zafi ya fi na methylcellulose girma. Misali, maganin ruwa na 2% hydroxypropyl methylcellulose tare da abun ciki na rukuni na methoxy DS=0.73 da abun ciki na rukuni na hydroxypropyl MS=0.46 yana da danko na 500mpa a 20°C. Zazzaɓin gel ɗin samfurin S yana kusa da 100 ° C, yayin da na methylcellulose a cikin zafin jiki ɗaya shine kusan 55 ° C. Dangane da narkewar sa a cikin ruwa, shi ma an inganta shi sosai. Misali, bayan da aka murkushe hydroxypropyl methylcellulose (siffar barbashi shine 0.2 ~ 0.5mm, danko na 4% ruwa a 20 ° C shine 2pA·S, ana iya amfani dashi a dakin da zafin jiki ba tare da sanyaya ba. Sauƙaƙe narke cikin ruwa).

 

(2) Solubility na hydroxypropyl methylcellulose a cikin kwayoyin kaushi Narkewar hydroxypropyl methylcellulose a cikin kaushi na kwayoyin halitta shima ya fi na methylcellulose kyau. Methylcellulose yana buƙatar digiri na maye gurbin methoxy na 2.1 Abubuwan da ke sama sun ƙunshi babban danko hydroxypropyl methylcellulose tare da hydroxypropyl MS=1.5 ~ 1.8 da methoxy DS=0.2 ~ 1.0, tare da jimlar maye gurbin fiye da 1.8, kuma suna da sauƙin narkewa a cikin methan mai anhydrous. ethanol mafita. Thermoplastic da ruwa mai narkewa. Hakanan yana narkewa a cikin chlorinated hydrocarbons kamar methylene chloride da chloroform, da sauran kaushi kamar acetone, isopropyl barasa da diacetone barasa. Solubility a cikin kwayoyin kaushi yana da kyau fiye da solubility na ruwa.

 

2. Abubuwan da ke shafar danko na hydroxypropyl methylcellulose

Hydroxypropyl methylcellulose viscosity factor daidaitaccen ma'aunin danko na hydroxypropyl methylcellulose daidai yake da sauran ethers cellulose, kuma ana auna shi a 20 ° C tare da 2% bayani mai ruwa a matsayin daidaitattun. Danko na samfurin iri ɗaya yana ƙaruwa yayin da haɗuwa ya karu. Don samfuran da ke da taro iri ɗaya da nau'ikan nau'ikan ƙwayoyin cuta daban-daban, samfurin tare da mafi girman nauyin kwayoyin yana da ɗanko mafi girma. Alakarsa da zafin jiki yayi kama da na methylcellulose. Lokacin da zafin jiki ya tashi, danko ya fara raguwa, amma lokacin da ya kai wani zafin jiki, danko ya tashi ba zato ba tsammani kuma gelation yana faruwa. Ƙananan samfurori suna da zafin gelling mafi girma fiye da samfurori masu danko. Ma'anar gel ba wai kawai yana da alaƙa da danko na ether ba, amma har ma yana da alaƙa da rabon abun ciki na methoxy da ƙungiyoyin hydroxypropyl a cikin ether da jimlar matakin maye gurbin. Dole ne a lura cewa hydroxypropyl methylcellulose shima pseudoplastic ne; Maganin sa suna da ƙarfi lokacin da aka adana su a cikin zafin jiki kuma kada ku nuna raguwar danko, sai dai yiwuwar lalatawar enzymatic.

 

3. Hydroxypropyl methylcellulose acid da alkaline resistant

Hydroxypropyl methylcellulose acid ne mai juriya da alkaline. Hydroxypropyl methyl cellulose ne acid da kuma alkali resistant. Gabaɗaya ya tsaya tsayin daka kuma ƙimar pH ba zai shafe shi a kewayon PH2 ~ 12 ba. Yana iya jure wani adadin acid mai rauni, irin su formic acid, acetic acid, da lemo. Acid, succinic acid, phosphoric acid amma maida hankali acid yana da tasirin rage danko. Alkaki irin su caustic soda, caustic potassium, da ruwan lemun tsami ba su da wani tasiri a kansa, amma sakamakon dan kadan ya kara dankon maganin zai ragu daga baya.

 

4. Hydroxypropyl methylcellulose za a iya hade

Hydroxypropyl methylcellulose bayani za a iya gauraye da ruwa-mai narkewa polymer mahadi don samar da uniform da m bayani tare da mafi girma danko. Wadannan mahadi na polymer sun hada da polyethylene glycol, polyvinyl acetate, polysiloxane, polymethyl vinyl siloxane, hydroxyethyl cellulose da methyl cellulose. Abubuwan da ake amfani da su na polymer na halitta irin su ɗanɗano na acacia, ɗanɗano ɗan waken fari, ɗanɗanon fari, da dai sauransu suma suna da kyakkyawar haɗuwa. maganinta. Hydroxypropyl methylcellulose kuma ana iya haɗa shi da stearic acid ko mannitol palmitate ko sorbitol, kuma ana iya haɗa shi da glycerin, sorbitol da mannitol. Wadannan mahadi za a iya amfani da su azaman hydroxypropyl methylcellulose plasticizers wakili.

 

5. Hydroxypropyl methylcellulose ba shi da narkewa a cikin ruwa

Hydroxypropyl methylcellulose ba shi da narkewa a cikin ethers cellulose mai narkewa da ruwa kuma yana iya kasancewa mai haɗin kai-giciye tare da aldehydes, yana sa waɗannan ethers masu narkewar ruwa su yi hazo a cikin maganin kuma su zama marar narkewa a cikin ruwa. Kuma sanya hydroxypropyl methylcellulose mai narkewa a cikin aldehydes, formaldehyde, glioxal, succinic acid, dialdehyde, da dai sauransu Lokacin amfani da formaldehyde, ya kamata a biya kulawa ta musamman ga darajar pH na maganin. Daga cikin su, glioxal yana amsawa da sauri, don haka ana amfani da shi a cikin masana'antar Glyoxal ana amfani da shi azaman wakili mai haɗin kai a cikin samarwa. -Wakilin Crosslinking. Matsakaicin nau'in nau'in nau'in nau'in haɗin kai a cikin maganin shine 0.2% zuwa 10% na yawan ether, kuma mafi kyau shine 7% zuwa 10%. Idan ana amfani da glycoxal, 3.3% zuwa 6% ya fi dacewa. Yawan zafin jiki na gabaɗaya shine 0 ~ 30 ℃ kuma lokacin shine 1 ~ 120min. Ana buƙatar ɗaukar matakin haɗin kai a ƙarƙashin yanayin acidic. Gabaɗaya, ana ƙara inorganic ƙarfi acid ko Organic carboxylic acid a cikin maganin don daidaita pH na maganin zuwa kusan 2 zuwa 6, zai fi dacewa tsakanin 4 da 6, sa'an nan kuma ana ƙara aldehydes don aiwatar da halayen haɗin kai. Acid ɗin da aka yi amfani da su sun haɗa da hydrochloric acid, sulfuric acid, phosphoric acid, formic acid, acetic acid, glycolic acid, succinic acid ko citric acid, daga cikinsu formic acid ko acetic acid shine mafi kyau, kuma formic acid shine mafi kyau. Hakanan za'a iya ƙara acid da aldehydes lokaci guda don haye hanyar haɗin maganin a cikin kewayon pH da ake so. Ana amfani da wannan amsa sau da yawa a mataki na ƙarshe na tsarin shirye-shiryen ether cellulose don sa ether cellulose ba zai iya narkewa ba kuma sauƙaƙe wankewa da tsarkakewa tare da ruwa 20 ~ 25 ° C. Lokacin amfani da samfurin, zaku iya ƙara abubuwan alkaline zuwa maganin samfurin don daidaita pH na maganin ya zama alkaline ta yadda samfurin zai iya narkewa cikin sauri a cikin maganin. Hakanan za'a iya amfani da wannan hanyar lokacin da aka shirya fim ta amfani da maganin ether cellulose sannan a sarrafa fim ɗin zuwa fim ɗin da ba zai iya narkewa ba.

 

6. Hydroxypropyl methylcellulose anti-enzyme

Abubuwan da ake samu na cellulose na hydroxypropyl methylcellulose suna da juriya ga enzymes. Misali, kowane rukunin anhydroglucose yana da alaƙa da ƙarfi tare da rukunin maye kuma ba ya da saurin yashwar ƙananan ƙwayoyin cuta da kamuwa da cuta. Koyaya, a zahiri, ƙimar maye gurbin da aka gama ya wuce 1. Hakanan ana iya lalata shi ta hanyar enzymes, wanda ke nuna cewa matakin maye gurbin kowane rukuni a cikin sarkar cellulose bai dace ba, kuma ƙwayoyin cuta na iya lalata ƙungiyoyin anhydroglucose da ba a maye gurbin su ba. sugar, wanda za a iya tunawa da microorganisms a matsayin abinci. Saboda haka, idan matakin ether maye gurbin cellulose ya karu, juriya na ethers cellulose zuwa harin enzymatic zai karu. An ba da rahoton cewa a ƙarƙashin yanayin sarrafawa, hydroxypropyl methylcellulose (DS = 1.9), methylcellulose (DS = 1.83), methylcellulose (DS=1.66), hydroxyethylcellulose (1.7%) Sauran viscosities sune 13.2%, 7.3%, 3.8% da 1.7% bi da bi. Hydroxypropyl methylcellulose yana da ƙarfi anti-enzyme capabilities. Ana iya ganin cewa hydroxypropyl methylcellulose yana da kyakkyawan juriya na enzyme, tare da kyakkyawan tarwatsawa, daɗaɗawa da kaddarorin fina-finai, ana iya amfani da shi a cikin suturar emulsion, da dai sauransu, kuma gabaɗaya baya buƙatar ƙarin abubuwan kiyayewa. Duk da haka, don hana maganin daga ajiya na dogon lokaci ko yiwuwar gurɓatawar waje, za'a iya ƙara abubuwan da ake amfani da su, kuma za'a iya ƙayyade zaɓin abubuwan da aka tsara bisa ga bukatun ƙarshe na mafita. Phenylmercuric acetate da manganese fluorosilicate suna da tasiri masu tasiri, amma suna da guba kuma dole ne a kula da su tare da kulawa. Gabaɗaya, ana iya ƙara 1 zuwa 5 MG na phenylmercuric acetate zuwa kowace lita na bayani.

 

7. Ayyukan hydroxypropyl methylcellulose membrane

Hydroxypropyl methylcellulose kayan aikin fim Hydroxypropyl methylcellulose yana da kyawawan kaddarorin yin fim. Lokacin da maganin ruwa mai ruwa ko maganin kaushi na halitta ya kasance mai rufi akan farantin gilashi, ya zama fim mara launi, bayyananne kuma mai tauri bayan bushewa. . Yana da juriya mai kyau da danshi kuma ya kasance mai ƙarfi a yanayin zafi mai yawa. Idan an ƙara masu filastik hygroscopic, za a iya haɓaka haɓakawa da sassauci, kuma ana iya inganta haɓaka. Plasticizers irin su glycerol da sorbitol sun fi dacewa. Mahimmancin bayani na gaba ɗaya shine 2% ~ 3%, kuma ƙwayar filastik shine 10% ~ 20% na ether cellulose. Idan ana buƙatar abun ciki na filastik don zama babba, colloid syneresis zai faru a ƙarƙashin babban zafi. Ƙarfin ƙarfin fim ɗin da aka ƙara da filastik ya fi girma fiye da na fim ɗin ba tare da filastik ba, kuma yana ƙaruwa tare da adadin filastik. Har ila yau, hygroscopicity na fim yana ƙaruwa tare da adadin filastik.


Lokacin aikawa: Fabrairu-01-2024
WhatsApp Online Chat!