Hydroxypropyl methylcellulose (Hypromellose), yomwe imadziwikanso kuti hypromellose, ndi ufa kapena granule woyera mpaka woyera, womwe uli ndi makhalidwe osungunuka m'madzi ozizira komanso osasungunuka m'madzi otentha mofanana ndi methyl cellulose.Gulu la hydroxypropyl ndi gulu la methyl limaphatikizidwa ndi mphete ya shuga ya anhydrous ya cellulose ndi ether bond, yomwe ndi mtundu wa ether wopanda ionic cellulose.Ndi semisynthetic, inactive, viscoelastic polima yomwe imagwiritsidwa ntchito ngati mafuta mu ophthalmology, kapena ngati chothandizira kapena galimoto mumankhwala apakamwa.
kukonzekera
Zamkati za pepala la kraft pepala zamkati zomwe zimachokera ku matabwa a pine okhala ndi alpha cellulose 97%, kukhuthala kwamkati kwa 720 ml / g, ndipo pafupifupi ulusi wautali wa 2.6 mm adamizidwa mu 49% NaOH yankho lamadzi pa 40 ° C. 50 masekondi;zamkati zotulukazo zidafinyidwa kuti zichotse 49% yamadzi amadzi NaOH kuti ipeze cellulose ya alkali.Chiŵerengero cha kulemera kwa (49% NaOH yankho lamadzimadzi) ku (zokhazikika mu zamkati) mu sitepe ya impregnation inali 200. Kulemera kwa chiwerengero cha (NaOH zomwe zili mu alkali cellulose zomwe zinapezedwa) ndi (zolimba mu zamkati) zinali 1.49.Ma cellulose a alkali omwe adapezedwa (makg 20) adayikidwa mu chopondera chokhala ndi jekete ndikugwedeza mkati, kenako amasamutsidwa ndikutsukidwa ndi nayitrogeni kuti achotse mpweya wokwanira mu choyatsira.Kenako, kusonkhezera kwamkati kunkachitika ndikuwongolera kutentha kwa riyakitala mpaka 60 ° C.Kenako, 2.4 kg ya dimethyl ether idawonjezedwa, ndipo kutentha kwa riyakitala kumayendetsedwa kuti kusungidwe pa 60 ° C.Mukawonjezera dimethyl ether, onjezerani dichloromethane kuti chiŵerengero cha molar cha (dichloromethane) ku (gawo la NaOH mu cellulose yamchere) ndi 1.3, ndikuwonjezera propylene oxide kupanga (propylene oxide) ndi (mu zamkati) Chiŵerengero cha kulemera kwa zinthu zolimba) idasinthidwa kukhala 1.97, pomwe kutentha kwa riyakitala kumayendetsedwa kuchokera ku 60 ° C mpaka 80 ° C.Pambuyo pa kuwonjezera methyl chloride ndi propylene oxide, kutentha kwa riyakitala kumayendetsedwa kuchokera ku 80 ° C mpaka 90 ° C.Kuphatikiza apo, zomwe zimachitikazo zidapitilira 90 ° C kwa mphindi 20.Ndiye, mpweya anali akutuluka riyakitala, ndiye yosakongola hydroxypropyl methylcellulose anachotsedwa riyakitala.Kutentha kwa hydroxypropyl methylcellulose pa nthawi yotulutsidwa kunali 62 digiri C.The zochulukirachulukira 50% tinthu kukula mu tinthu kukula kugawa zochokera kuchulukirachulukira kulemera anatsimikiza zochokera chiŵerengero cha yaiwisi hydroxypropyl methylcellulose kudutsa mipata asanu sieves, aliyense sieve kukhala osiyana kutsegula kukula, anayeza.Zotsatira zake, pafupifupi tinthu kukula kwa coarse particles anali 6.2 mm.The motero analandira yaiwisi hydroxypropyl methylcellulose anayambitsa mosalekeza biaxial kneader (KRC kneader S1, L/D = 10.2, voliyumu mkati 0.12 malita, rotational liwiro 150 rpm) pa mlingo wa 10 kg/hr, ndipo kuwonongeka analandira.mankhwala a hydroxypropyl methylcellulose.Kukula kwa tinthu kakang'ono kunali 1.4 mm monga kuyeza mofanana pogwiritsa ntchito sieve za 5 zosiyana zotsegula.Kwa hydroxypropyl methylcellulose yomwe yavunda mu thanki yokhala ndi kutentha kwa jekete, onjezerani madzi otentha pa 80 ° C mu kuchuluka kwakuti (Kulemera kwa kuchuluka kwa cellulose) mpaka (kuchuluka kwa slurry) kunasinthidwa kukhala 0.1, ndi slurry anapezeka.slurry imatenthedwa pa kutentha kwa 80 ° C kwa mphindi 60.Kenako, slurry anadyetsedwa mu preheated rotary kuthamanga fyuluta (mankhwala BHS-Sonthofen) ndi kasinthasintha liwiro 0.5 rpm.Kutentha kwa slurry kunali 93 ° C.Kutsekemera kumaperekedwa pogwiritsa ntchito mpope, ndipo kuthamanga kwa mpope kunali 0.2 MPa.Kukula kotsegulira kwa fyuluta ya fyuluta ya rotary pressure inali 80 μm, ndipo malo osefera anali 0.12 m 2.Slurry yomwe imaperekedwa ku fyuluta ya rotary pressure imasinthidwa kukhala keke ya fyuluta ndi kusefera kwa fyuluta.Pambuyo popereka nthunzi ya 0,3 MPa ku keke yomwe inapezedwa, madzi otentha pa 95 ° C anaperekedwa mochuluka kotero kuti kulemera kwa chiŵerengero cha (madzi otentha) kuti (zolimba za hydroxypropyl methylcellulose mutatha kutsuka) zinali 10.0, Kenako, sefa kudzera fyuluta.Madzi otentha amaperekedwa ndi mpope pa kuthamanga kwa 0.2 MPa.Madzi otentha ataperekedwa, nthunzi ya 0,3 MPa inaperekedwa.Kenako, chotsukidwacho pa fyuluta pamwamba chimachotsedwa ndi scraper ndikutulutsidwa mu makina ochapira.Masitepe oyambira kudyetsa slurry mpaka kutulutsa mankhwala otsuka amachitika mosalekeza.Chifukwa cha kuyeza pogwiritsa ntchito hygrometer yowumitsa kutentha, madzi omwe adatsukidwa adatulutsidwa anali 52.8%.Chotsukidwacho chotulutsidwa mu sefa ya rotary pressure chinaumitsidwa pogwiritsa ntchito chowumitsira mpweya pa 80° C., ndikusindidwa mu mphero ya Victory mphero kuti apeze hydroxypropyl methylcellulose.
ntchito
Izi zimagwiritsidwa ntchito ngati thickener, dispersant, binder, emulsifier ndi stabilizer mumakampani opanga nsalu.Amagwiritsidwanso ntchito kwambiri popanga utomoni, petrochemical, ceramics, mapepala, zikopa, mankhwala, chakudya, zodzoladzola ndi mafakitale ena.
Nthawi yotumiza: Nov-15-2022