Chemical katundu ndi kaphatikizidwe wa hydroxypropyl methylcellulose (HMPC)

Hydroxypropyl methylcellulose (HPMC) ndi polima opangidwa kuchokera ku cellulose ndipo amagwiritsidwa ntchito ngati thickener, emulsifier, and stabilizer m'mafakitale osiyanasiyana monga chakudya, mankhwala, ndi zodzoladzola. HMPC ndi hydroxypropylated yochokera ku methylcellulose (MC), madzi osungunuka a nonionic cellulose ether opangidwa ndi mayunitsi a methoxylated ndi hydroxypropylated cellulose. HMPC imagwiritsidwa ntchito kwambiri ngati chothandizira pakupanga mankhwala chifukwa chakusapha, biocompatibility, ndi biodegradability.

HMPC Chemical properties:

Mankhwala a HMPC amadziwika ndi kukhalapo kwa magulu a hydroxyl ndi ether mu kapangidwe kake ka maselo. Magulu a hydroxyl a cellulose amatha kugwiritsidwa ntchito pogwiritsa ntchito mitundu yosiyanasiyana yamankhwala, monga etherification, esterification, ndi oxidation, kuyambitsa magulu osiyanasiyana ogwira ntchito mumsana wa polima. HMPC ili ndi magulu onse a methoxy (-OCH3) ndi hydroxypropyl (-OCH2CHOHCH3), omwe amatha kuwongoleredwa kuti apereke zinthu zosiyanasiyana monga solubility, viscosity ndi gelation.

HMPC imasungunuka kwambiri m'madzi, ndikupanga njira zomveka bwino komanso zowoneka bwino pamiyeso yotsika. Kukhuthala kwa mayankho a HMPC kumatha kusinthidwa posintha kuchuluka kwa kusintha (DS) kwamagulu a hydroxypropyl, komwe kumatsimikizira kuchuluka kwa malo osinthidwa a hydroxyl pagawo la shuga. Kukwera kwa DS, kumachepetsa kusungunuka komanso kumapangitsanso kukhuthala kwa njira ya HMPC. Katunduyu angagwiritsidwe ntchito kuwongolera kutulutsidwa kwa zinthu zogwira ntchito kuchokera kumankhwala amankhwala.

HMPC imawonetsanso machitidwe a pseudoplastic, kutanthauza kuti kukhuthala kumachepa ndi kuchuluka kwa kukameta ubweya. Katunduyu amapangitsa kuti ikhale yoyenera ngati chowonjezera chamadzimadzi chomwe chimafunikira kupirira mphamvu zometa ubweya panthawi yokonza kapena kugwiritsa ntchito.

HMPC imakhala yokhazikika mpaka kutentha kwina, pamwamba pomwe imayamba kutsika. Kutentha kwa kuwonongeka kwa HMPC kumadalira DS ndi kuchuluka kwa polima mu yankho. Kutentha kwa kutentha kwa HMPC kumanenedwa kukhala 190-330 ° C.

Kaphatikizidwe ka HMPC:

HMPC imapangidwa ndi etherification reaction ya cellulose ndi propylene oxide ndi methylethylene oxide pamaso pa chothandizira zamchere. Zomwe zimachitika zimapitilira magawo awiri: choyamba, magulu a methyl a cellulose amasinthidwa ndi propylene oxide, kenako magulu a hydroxyl amasinthidwanso ndi methyl ethylene oxide. DS ya HMPC imatha kuwongoleredwa ndikusintha chiŵerengero cha molar cha propylene oxide ku cellulose panthawi ya kaphatikizidwe.

Zimene zimachitika kawirikawiri ikuchitika mu amadzimadzi sing'anga pa okwera kutentha ndi kuthamanga. Chothandizira chachikulu nthawi zambiri chimakhala sodium kapena potaziyamu hydroxide, yomwe imapangitsa kuti magulu a cellulose hydroxyl azigwira ntchito ku mphete za epoxide za propylene oxide ndi methylethylene oxide. The anachita mankhwala ndiye neutralized, osambitsidwa ndi zouma kupeza chomaliza HMPC mankhwala.

HMPC imathanso kupangidwa pochita cellulose ndi propylene oxide ndi epichlorohydrin pamaso pa zolimbikitsa za asidi. Njirayi, yomwe imadziwika kuti epichlorohydrin process, imagwiritsidwa ntchito popanga zotumphukira za cationic cellulose, zomwe zimayimbidwa bwino chifukwa cha kukhalapo kwa magulu a quaternary ammonium.

Pomaliza:

HMPC ndi polima multifunctional yokhala ndi mankhwala abwino kwambiri oyenera kugwiritsa ntchito zosiyanasiyana m'mafakitale osiyanasiyana. Kaphatikizidwe ka HMPC kumaphatikizapo etherification reaction ya cellulose ndi propylene oxide ndi methylethylene oxide pamaso pa chothandizira zamchere kapena chothandizira acidic. Makhalidwe a HMPC amatha kusinthidwa ndikuwongolera DS ndi kuchuluka kwa polima. Chitetezo ndi biocompatibility ya HMPC imapangitsa kukhala chisankho chabwino pamapangidwe amankhwala.