Njira Yopangira Liquid-Phase Yopangira Hydroxypropyl Methyl Cellulose (HPMC)

Hydroxypropyl methyl cellulose (HPMC) ndi ether ya cellulose yomwe imagwiritsidwa ntchito kwambiri m'mafakitale osiyanasiyana ndi mankhwala chifukwa champhamvu zake zakuthupi komanso zamankhwala. HPMC imapangidwa nthawi zambiri kudzera munjira zosiyanasiyana, kuphatikiza njira yopangira madzi-gawo.

Njira yopangira madzi-gawo ndi njira yamankhwala yomwe imakhudza momwe methyl cellulose (MC) imachitira ndi propylene oxide (PO) kenako ndi propylene glycol (PG) pansi pazifukwa zina. Ndondomekoyi ikuphatikizapo zotsatirazi:

1. Kukonzekera kwa Methyl Cellulose (MC)

MC imapezeka pochiza cellulose ndi alkali ndiyeno methylating ndi methyl chloride. Mlingo wa kulowetsedwa (DS) wa MC umatsimikizira katundu wake ndipo ukhoza kuwongoleredwa ndi kusiyanasiyana komwe kumachitika.

2. Kukonzekera kwa Propylene Oxide (PO)

PO imakonzedwa ndi okosijeni wa propylene pogwiritsa ntchito mpweya kapena mpweya pamaso pa chothandizira. Zomwe zimachitika pa kutentha kwambiri ndi kupanikizika kuti zitsimikizire zokolola zambiri za PO.

3. Zochita za MC ndi PO

Zochita za MC ndi PO zimachitika pamaso pa chothandizira ndi zosungunulira monga toluene kapena dichloromethane. Zotsatira zake zimakhala zotentha kwambiri ndipo zimatulutsa kutentha, komwe kuyenera kuyendetsedwa kuti zisawonongeke.

4. Kukonzekera kwa Propylene Glycol (PG)

PG imakonzedwa ndi hydrolysis ya propylene oxide pogwiritsa ntchito madzi kapena asidi kapena chothandizira choyambira. Zomwe zimachitikazi zimachitika mofatsa kuti mupeze zokolola zambiri za PG.

5. Kuchita kwa MC-PO ndi PG

Chogulitsa cha MC-PO chimasinthidwa ndi PG pamaso pa chothandizira komanso chosungunulira monga ethanol kapena methanol. Zomwe zimachititsanso kuti zikhale zotentha kwambiri ndipo zimatulutsa kutentha, komwe kuyenera kuyendetsedwa kuti zisawonongeke.

6. Kuchapa ndi Kuyanika

Zitachitika, mankhwalawa amatsukidwa ndi madzi ndikuwumitsa kuti apeze HPMC. Mankhwalawa nthawi zambiri amayeretsedwa pogwiritsa ntchito njira zosefera ndi centrifugation kuchotsa zonyansa zilizonse.

Njira yopangira madzi yamadzimadzi imakhala ndi maubwino angapo kuposa njira zina, kuphatikiza zokolola zambiri, zotsika mtengo, komanso zosavuta. Zomwezo zimatha kuchitidwa muchombo chimodzi, kuchepetsa kufunikira kwa zida zovuta ndi njira.

Komabe, njira yopangira madzi-gawo ilinso ndi zovuta zina. Zomwe zimachitika zimatha kuyambitsa kutentha, komwe kuyenera kuyang'aniridwa mosamala kuti tipewe zovuta zachitetezo. Kugwiritsiridwa ntchito kwa zosungunulira kungathenso kuwononga chilengedwe ndi thanzi, ndipo njira yoyeretsera ingakhale yowononga nthawi komanso yodula.

Pomaliza, njira yopangira madzi-gawo ndi njira yomwe imagwiritsidwa ntchito kwambiri popanga HPMC. Njirayi imakhudza momwe MC ndi PO ndi PG amachitira pamikhalidwe ina, kutsatiridwa ndi kuyeretsedwa ndi kuyanika. Ngakhale kuti njirayi ili ndi zovuta zina, ubwino wake umapangitsa kukhala chisankho chodziwika bwino cha mafakitale ndi mankhwala.