Kodi Hydroxypropyl Methylcellulose Amapangidwa Kuchokera Chiyani?

Hydroxypropyl methylcellulose (HPMC) ndi polima yopangidwa ndi semisynthetic yomwe imagwiritsidwa ntchito m'mafakitale osiyanasiyana, kuphatikiza zomangamanga, chakudya, mankhwala, ndi zinthu zosamalira anthu. Imayamikiridwa chifukwa cha kuthekera kwake kukonza ma rheological properties of formulations, komanso kugwirizana kwake ndi zosakaniza zina komanso kawopsedwe ake otsika. Kuti mumvetsetse momwe HPMC imapangidwira, ndikofunikira kumvetsetsa kaye kapangidwe ka cellulose ndi katundu wake.

Cellulose ndi mndandanda wautali wa mamolekyu a glucose omwe amapezeka m'makoma a cell a zomera. Mamolekyu a shuga amalumikizidwa palimodzi ndi ma beta-1,4-glycosidic bond, kupanga unyolo wozungulira. Kenako maunyolowo amalumikizidwa pamodzi ndi ma hydrogen bond ndi mphamvu za Van der Waals kupanga zolimba, zopanga ulusi. Cellulose ndi mankhwala omwe amapezeka kwambiri padziko lapansi, ndipo amagwiritsidwa ntchito pazinthu zosiyanasiyana, kuphatikizapo mapepala, nsalu, ndi zomangira.

Ngakhale cellulose ili ndi zinthu zambiri zothandiza, nthawi zambiri imakhala yolimba kwambiri komanso yosasungunuka kuti igwiritsidwe ntchito m'mapangidwe ambiri. Kuti athane ndi izi, asayansi apanga zotuluka zingapo zosinthidwa za cellulose, kuphatikiza HPMC. HPMC imapangidwa ndikusintha mapadi achilengedwe kudzera pamachitidwe angapo amankhwala.

Gawo loyamba popanga HPMC ndikupeza zinthu zoyambira pa cellulose. Izi zitha kuchitika pochotsa cellulose kuchokera ku mbewu monga zamkati, thonje, kapena nsungwi. Ma cellulose amathandizidwa ndi njira ya alkaline, monga sodium hydroxide kapena potaziyamu hydroxide, kuchotsa zonyansa ndikuphwanya ulusi wa cellulose kukhala tinthu ting'onoting'ono. Njirayi imadziwika kuti mercerization, ndipo imapangitsa kuti cellulose ikhale yogwira ntchito komanso yosavuta kusintha.

Pambuyo pa mercerization, cellulose imayendetsedwa ndi kusakaniza kwa propylene oxide ndi methyl chloride kuyambitsa magulu a hydroxypropyl ndi methyl pamsana wa cellulose. Magulu a hydroxypropyl amawonjezeredwa kuti azitha kusungunuka komanso kusunga madzi a cellulose, pomwe magulu a methyl amawonjezedwa kuti awonjezere kukhazikika komanso kuchepetsa kuyambiranso kwa cellulose. Zomwe zimachitika nthawi zambiri zimachitika pamaso pa chothandizira, monga sodium hydroxide kapena potaziyamu hydroxide, komanso pansi pa kutentha, kuthamanga, ndi nthawi yochitira.

Digiri ya m'malo (DS) ya HPMC imatanthawuza kuchuluka kwa magulu a hydroxypropyl ndi methyl omwe amalowetsedwa pamsana wa cellulose. DS imatha kusiyanasiyana kutengera zomwe HPMC ikufunidwa komanso momwe ikugwiritsidwira ntchito. Nthawi zambiri, kukwera kwa DS kumapangitsa kuti HPMC ikhale yocheperako komanso kusungunuka mwachangu, pomwe kutsika kwa DS kumapangitsa kuti HPMC ikhale ndi kukhuthala kwakukulu komanso kusungunuka pang'onopang'ono.

Zomwezo zitatha, zomwe zimapangidwira zimatsukidwa ndikuwumitsidwa kuti apange ufa wa HPMC. Njira yoyeretsera imaphatikizapo kuchotsa mankhwala aliwonse osakhudzidwa, zosungunulira zotsalira, ndi zonyansa zina ku HPMC. Izi zimachitika pophatikiza kuchapa, kusefera, ndi kuyanika.

Chomalizacho ndi ufa woyera mpaka woyera wopanda fungo komanso wosakoma. HPMC ndi sungunuka m'madzi ndi zosungunulira zambiri organic, ndipo akhoza kupanga angelo, mafilimu, ndi nyumba zina malinga ndi zikhalidwe ntchito. Ndi polima yopanda ionic, kutanthauza kuti ilibe magetsi, ndipo nthawi zambiri imatengedwa kuti ndi yopanda poizoni komanso yotetezeka kuti igwiritsidwe ntchito pazinthu zosiyanasiyana.

HPMC ntchito zosiyanasiyana formulations, kuphatikizapo utoto, zomatira, sealants, mankhwala, ndi zakudya zakudya. Pazomangamanga, HPMC imagwiritsidwa ntchito ngati chokhuthala, chomangira, komanso chopangira filimu muzinthu zopangira simenti ndi gypsum, monga matope, ma grouts, ndi zophatikiza.