Zeziphi imathiriyeli ekrwada ye-hydroxypropyl methylcellulose?

IHydroxypropylmethylcellulose (HPMC) yipolymer esebenzayo ephuma kwi cellulose yendalo. Isetyenziswa ngokuqhelekileyo kumashishini ahlukeneyo, kubandakanywa amayeza, ukutya, ukwakhiwa kunye nezithambiso. Imveliso ye-HPMC ibandakanya iintlobo ngeentlobo zemathiriyeli ekrwada kunye nenkqubo enamanyathelo amaninzi.

ISelulosi:

Umthombo: Eyona mathiriyeli ekrwada ye-HPMC yi-cellulose, i-carbohydrate enzima efumaneka kwiindonga zeeseli zesityalo. Owona mthombo uxhaphakileyo weselulosi kwimveliso ye-HPMC yintlama yeenkuni, kodwa eminye imithombo efana ne-cotton linters ingasetyenziswa.
Ukulungiselela: I-Cellulose idla ngokuphathwa ukuze isuse ukungcola kwaye iqhutywe kwifomu efanelekileyo yokuguqulwa okungaphezulu.

Isiseko:

Uhlobo: I-sodium hydroxide (NaOH) okanye i-potassium hydroxide (KOH) isoloko isetyenziswa njengesiseko ngexesha lezigaba zokuqala zemveliso ye-HPMC.
Umsebenzi: I-alkali isetyenziselwa ukunyanga i-cellulose, ibangela ukuba idumbe kwaye itshabalalise isakhiwo sayo. Le nkqubo, ebizwa ngokuba yialkalization, ilungiselela i-cellulose ukusabela okungakumbi.

I-alkali etherifying agent:

I-Hydroxypropylating agent: I-Propylene oxide isoloko isetyenziselwa ukwazisa amaqela e-hydroxypropyl kwi-cellulose backbone. Eli nyathelo linika ukunyibilika kunye nezinye iimpawu ezinqwenelekayo kwiselulosi.
I-Methylating agents: I-Methyl chloride okanye i-dimethyl sulfate isoloko isetyenziselwa ukwazisa amaqela e-methyl kwisakhiwo se-cellulose, ngaloo ndlela iphucula iipropati zayo zonke.

Iarhente yeMethylating:

I-Methanol: I-Methanol isetyenziswa ngokuqhelekileyo njenge-solvent kunye ne-reactant kwiinkqubo ze-methylation. Inceda ukwazisa amaqela e-methyl kumakhonkco e-cellulose.

Hydroxypropylating agent:

Ipropylene oxide: Yimathiriyeli ekrwada engundoqo yokwazisa amaqela e-hydroxypropyl kwiselulosi. Ukusabela phakathi kwepropylene oxide kunye neselulosi kwenzeka phantsi kweemeko ezilawulwayo.

I-catalyst:

I-Acid Catalyst: I-acid catalyst, efana ne-asidi ye-sulfuric, isetyenziselwa ukukhuthaza ukusabela kwe-etherification. Banceda ukulawula amazinga okusabela kunye neempawu zemveliso.

Isinyibilikisi:

Amanzi: Amanzi ahlala esetyenziswa njengesinyibilikisi kumanqanaba ahlukeneyo enkqubo yokuvelisa. Kubalulekile ukunyibilikisa ii-reactants kunye nokukhuthaza ukusabela phakathi kwe-cellulose kunye ne-etherifying agents.

Ukungathathi hlangothi:

I-sodium hydroxide (NaOH) okanye i-potassium hydroxide (KOH): isetyenziselwa ukunciphisa i-acid catalysts kunye nokulungelelanisa i-pH ngexesha lokudibanisa.

isicoci:

I-Filter Aids: Iintlobo ezahlukeneyo zezixhobo zokucoca zingasetyenziselwa ukususa ukungcola kunye neemveliso ezingafunekiyo ezivela kumxube wokuphendula.
Izicoci: Ukuhlamba ngamanzi okanye ezinye izinyibilikisi kunceda ukususa iikhemikhali ezishiyekileyo kunye nokungcola kwimveliso yokugqibela.

I-Desiccant:

Ukomisa umoya okanye i-oven: Emva kokuhlanjululwa, imveliso ingaba ngumoya okanye i-oven yomisiwe ukususa i-solvent kunye nokufuma okushiyekileyo.

Iarhente yolawulo lomgangatho:

IiReagents zohlalutyo: Ii-reagents ezahlukeneyo zisetyenziselwa iinjongo zolawulo lomgangatho ukuqinisekisa ukuba iimveliso ze-HPMC zihlangabezana nokusebenza okufunekayo kunye neenkcukacha.

Ukuveliswa kwe-hydroxypropyl methylcellulose kubandakanya ukuguqula i-cellulose ngoluhlu lwee-chemical reactions. Izinto eziluhlaza ziquka i-cellulose, i-alkali, i-etherifying agent, i-catalyst, i-solvent, i-agent engathathi hlangothi, i-agent yokucoca kunye ne-desiccant, edlala indima ebalulekileyo kwinkqubo yokudibanisa. Iimeko ezithile kunye nee-reagents ezisetyenzisiweyo zinokuhluka ngokuxhomekeke kwiipropati ezifunwayo kunye nokusetyenziswa kwemveliso yokugqibela ye-hydroxypropyl methylcellulose.