Ako mo te Mana Kounga o Hydroxypropyl Methyl Cellulose

E ai ki nga ahuatanga o naianei mo te hanga HPMC i roto i taku whenua, ko nga mea e pa ana ki te kounga o te hydroxypropyl methylcellulose ka tātarihia, i runga i tenei kaupapa, me pehea te whakapai ake i te taumata kounga o te hydroxypropyl methylcellulose ka korerohia me te ako, kia pai ai te whakaputa.

kupu matua:hydroxypropyl methylcellulose; kounga; whakahaere; rangahau

Ko te Hydroxypropyl methylcellulose (HPMC) he katote kore-wai-wairewa cellulose i konatunatuahia te etera i hangaia mai i te miro, te rakau, me te whakahiato ki te propylene oxide me te methyl chloride i muri i te pupuhi o te alkali. Cellulose hanumi ether he Ko te pärönaki whakarerekë o te etera whakakapi kotahi he pai ake te ahurei o te monoether taketake, a ka taea e ia te purei i te mahi o te cellulose ether kia matawhānui me te tino pai. I roto i te maha o nga etera whakauru, ko te hydroxypropyl methylcellulose te mea nui. Ko te tikanga whakarite ko te taapiri i te propylene oxide ki te cellulose alkaline. Ko te HPMC Ahumahi ka taea te korero hei hua mo te ao. Ko te tohu whakakapinga o te roopu methyl (te uara DS) ko te 1.3 ki te 2.2, ko te tohu whakakapi molar o te hydroxypropyl he 0.1 ki te 0.8. Ka kitea mai i nga korero o runga ake nei he rereke nga ihirangi me nga ahuatanga o te methyl me te hydroxypropyl i roto i te HPMC, ka puta ko te pokey o te hua whakamutunga me te rereke o te whakakotahitanga ka arahi ki nga rereketanga o te kounga o nga hua kua oti o nga momo hinonga whakaputa.

Ka whakaputahia e te Hydroxypropyl methylcellulose nga hua ether na roto i nga tauhohenga matū, he nui nga huringa i roto i te hanganga, te hanganga me nga ahuatanga, ina koa te whakarewatanga o te cellulose, ka taea te rereke i runga i te momo me te nui o nga roopu alkyl i whakauruhia. Tikina he pärönaki ether ka whakarewahia i roto i te wai, te wairewa alkali waimeha, nga whakarewa polar (pënei i te waihano, propanol) me nga whakarewa pararopi kore-polar (pënei i te benzene, ether), e tino whakawhänuihia ana nga momo me nga waahi tono o nga pärönaki cellulose.

1. Te awenga o te tukanga whakamaaramatanga hydroxypropyl methylcellulose ki te kounga

Ko te tukanga alkaliization te taahiraa tuatahi i roto i te waahanga tauhohenga o te hanga HPMC, a koinei hoki tetahi o nga waahanga tino nui. Ko te kounga o nga hua o te HPMC ka tino whakatauhia e te tukanga alkaliization, ehara i te tukanga etherification, na te mea ka pa tika te paanga o te waipiro ki te paanga o te etherification.

Ko te Hydroxypropyl methylcellulose e taunekeneke ana me te wairewa kawakore ki te hanga i te cellulose alkali, he tino hohenga. I roto i te tauhohenga etherification, te tauhohenga matua o te kaihoko etherification ki te pupuhi, te kuhu, me te etherification o te cellulose me Ko te tere o nga tauhohenga taha, te rite o te tauhohenga me nga taonga o te hua whakamutunga e pa ana ki te hanganga me te hanganga o te pūtau alkali, no reira ko te hanganga me nga ahuatanga matū o te cellulose alkali he kaupapa rangahau nui mo te hanga o te cellulose ether.

2. Te paanga o te pāmahana ki te kounga o te hydroxypropyl methylcellulose

I roto i tetahi kukū o KOH wairewa wai, te nui adsorption me te huamo tohu o hydroxypropyl methylcellulose ki alkali piki ki te heke o te pāmahana tauhohenga. Hei tauira, he rereke te putanga o te cellulose alkali ki te kukū o KOH: 15 %, 8% i te 10°C, me te 4.2% i te 5°C. Ko te tikanga o tenei ahua ko te hanga o te cellulose alkali he tukanga tauhohenga exothermic. Ka piki ake te pāmahana, ko te whakauru o te hydroxypropyl methylcellulose i runga i te alkali Ka heke te nui, engari ko te tauhohenga hydrolysis o te cellulose alkali ka tino piki ake, kaore i te pai ki te hanga o te cellulose alkali. Ka kitea mai i runga ake nei ko te whakaheke i te pāmahana waimaera he pai ki te whakatipuranga o te cellulose alkali me te aukati i te tauhohenga wai.

3. Ko te painga o nga taapiri ki te kounga o te hydroxypropyl methylcellulose

I roto i te punaha cellulose-KOH-wai, te taapiri—He nui te awe o te tote ki te hanga o te cellulose alkali. Ina he iti iho te kukū o te otinga KOH i te 13%, karekau te urunga o te cellulose ki te kawakore e pa ki te taapiri o te tote konupora konupora. A, no te te kukū o te wairewa rei he teitei ake i te 13%, i muri i te tāpiri pāhare pāporo pūhaumāota, te adsorption kitea o te cellulose ki alkali Ka piki ake te adsorption ki te kukū o te pāhare pāporo pūhaumāota, engari ka heke te kaha adsorption katoa, a ka nui haere te adsorption wai, na te Ko te taapiri o te tote i te nuinga o te waa kaore i te pai ki te whakamaarama me te pupuhi o te cellulose, engari ka taea e te tote te aukati i te hauwai me te whakahaere i te punaha Ko te wai kore utu ka pai ake te painga o te whakamaaramatanga me te whakamaarama.

4. Te awe o te tukanga whakaputa ki te kounga o te hydroxypropyl methylcellulose

I tenei wa, ko nga hinonga whakangao hydroxypropyl methylcellulose i roto i taku whenua te nuinga o te tango i te tikanga whakaputa tikanga whakarewa. Ko te mahi whakarite me te whakamaarama o te cellulose alkali ka mahia katoa i roto i te whakarewa pararopi koretake, na reira me parai te miro kua oti te para kia nui ake te waahi Mata me te hohenga kia pai ai te kounga o te hua kua oti.

Tāpirihia te cellulose, te whakarewa pararopi me te otinga kawakore ki roto i te reactor, me te whakamahi i te whakakorikori miihini kaha i tetahi pāmahana me te wa ki te whiwhi cellulose alkali me te whakakotahitanga rite me te iti o te paheketanga. Ko nga whakarewa waimeha pararopi (isopropanol, toluene, me etahi atu) he koretake, e tuku ana te hydroxypropyl methylcellulose i te wera rite i te wa o te hangahanga, e whakaatu ana i te ahunga whakamua o te tuku, me te whakaiti i te tauhohenga hydrolysis o te cellulose alkali i te huarahi rereke. te kounga alkali cellulose, i te nuinga o te wa ko te kukū o te reitia e whakamahia ana i roto i tenei hononga he 50%.

I muri i te rukutanga o te cellulose ki te rei, ka tino tetere me te taurite te kawakore o te cellulose alkali. He pai ake te pupuhi o te rei ki te cellulose, ka whakatakoto he turanga pai mo te tauhohenga etherification o muri mai. Ko te nuinga o nga mea whakangawari ko te isopropanol, te acetone, te toluene, me etahi atu. Ko nga papa o runga me o raro ka hangaia i te wa e whakaranu ana. Ko te paparanga o runga he isopropanol me te wai, ko te paparanga o raro he kawakore me te iti o te isopropanol. Ko te cellulose kua marara i roto i te punaha ka tino pa ki nga papa wai o runga me raro i raro i te whakaoho miihini. Te kawakore i roto i te punaha Ka huri te toenga wai kia puta ra ano te cellulose.

I te mea he cellulose katote kore-katote whakauru ether, ko te ihirangi o nga roopu hydroxypropyl methylcellulose kei runga i nga mekameka macromolecular rereke, ara, he rereke te owehenga tohatoha o nga roopu methyl me te hydroxypropyl ki te C o ia tuunga mowhiti huka. He nui ake te marara me te matapōkeretia, he uaua ki te whakapumau i te kounga o te hua.