Focus on Cellulose ethers

Yiziphi izici ezithinta ukugcinwa kwamanzi kwe-hydroxypropyl methylcellulose

Ukuphakama kwe-viscosity yei-hydroxypropyl methylcellulose, ngcono ukusebenza kokugcinwa kwamanzi. I-Viscosity iyipharamitha ebalulekile yokusebenza kwe-HPMC. Njengamanje, abakhiqizi abahlukene be-HPMC basebenzisa izindlela namathuluzi ahlukene ukukala i-viscosity ye-HPMC. Izindlela eziyinhloko yi-Haake Rotovisko, i-Hoppler, i-Ubbelohde ne-Brookfield.

Ngomkhiqizo ofanayo, imiphumela ye-viscosity elinganiswa ngezindlela ezahlukene ihluke kakhulu, futhi eminye iphinda kabili umehluko. Ngakho-ke, uma uqhathanisa i-viscosity, qiniseka ukuthi ukwenze phakathi kwezindlela ezifanayo zokuhlola, kufaka phakathi izinga lokushisa, i-rotor, njll.

Ngosayizi wezinhlayiyana, ukucoleka kwezinhlayiyana, kuba ngcono nokugcinwa kwamanzi. Ngemva kokuba izinhlayiya ezinkulu ze-cellulose ether zihlangane namanzi, indawo engaphezulu iyancibilika ngokushesha ukuze yakhe ijeli, egoqa izinto ukuvimbela ukungena okuqhubekayo kwama-molecule amanzi. . Kuthinta kakhulu umphumela wokugcina amanzi we-cellulose ether yayo, futhi ukuncibilika kungenye yezici zokukhetha i-cellulose ether. I-Fineness futhi iyinkomba yokusebenza ebalulekile ye-methyl cellulose ether. I-MC esetshenziselwa udaka lwempushana eyomile idingeka ukuthi ibe yimpushana, enomthamo wamanzi aphansi, futhi ukucoleka kudinga u-20% kuya ku-60% wesayizi wezinhlayiyana ukuba ube ngaphansi kuka-63um. Ubuhle buthinta ukunyibilika kwe-hydroxypropyl methylcellulose ether. I-coarse MC ivamise ukuba yi-granular, futhi kulula ukuyincibilika emanzini ngaphandle kwe-agglomeration, kodwa izinga lokuhlakazeka lihamba kancane, ngakho-ke alifanelekile ukusetshenziswa odakeni olomile. Odakeni lwempushana olomile, i-MC ihlakazwa phakathi kwezinto zikasimende ezifana nama-aggregates, izigcwalisi ezinhle nosimende. Impushana enhle ngokwanele kuphela engagwema ukuhlangana kwe-methyl cellulose ether lapho ixutshwa namanzi. Lapho i-MC yengezwe ngamanzi ukuze ihlakaze ama-agglomerates, kunzima ukuhlakazeka nokuhlakazeka. I-MC ene-coarser fineness ayigcini nje ngokumosha, kodwa futhi inciphisa amandla endawo odaka. Lapho udaka olunjalo lwempushana elomile lwakhiwe endaweni enkulu, isivinini sokuphulukisa se-powder eyomile sendawo siyancipha kakhulu, futhi ukuqhekeka kwenzeka ngenxa yezikhathi ezahlukene zokuphulukisa. Ukuze i-spray mortar isebenzisa ukwakhiwa kwemishini, ngenxa yesikhathi esifushane sokuvuselela, ukucwiliswa kuyadingeka ukuba kube phezulu.

Ngokuvamile, ukuphakama kwe-viscosity, kuba ngcono umphumela wokugcina amanzi. Kodwa-ke, ukuphakama kwe-viscosity futhi ukuphakama kwesisindo samangqamuzana e-MC, ukuncipha okuhambisanayo kokuncibilika kwayo, okunomthelela omubi emandleni nasezindaweni zokwakha zodaka. Ukuphakama kwe-viscosity, kusobala kakhulu umphumela wokuqina wodaka, kodwa awulingani. Lapho i-viscosity iphezulu, udaka olumanzi luyoba lunamathele kakhulu. Ngesikhathi sokwakhiwa, izonamathela ku-scraper futhi ibe nokunamathela okuphezulu ku-substrate. Kodwa yenza okuncane ukukhulisa amandla esakhiwo sodaka olumanzi ngokwalo. Ngesikhathi sokwakhiwa, ukusebenza kokusebenza kokulwa nokuncipha akubonakali. Ngokuphambene, amanye ama-ethers e-methyl cellulose e-low-viscosity ashintshiwe anokusebenza okuhle kakhulu ekuthuthukiseni amandla esakhiwo sodaka olumanzi.

Uma sikhulu inani le-cellulose ether engezwe odakeni, ngcono ukusebenza kokugcinwa kwamanzi, ukuphakama kwe-viscosity, ngcono ukusebenza kokugcinwa kwamanzi.

Ukucoleka kwe-HPMC nakho kunomthelela othile ekugcinweni kwayo kwamanzi. Ngokuvamile, kuma-methyl cellulose ether ane-viscosity efanayo kodwa ukucoleka okuhlukile, esimeni sesamba esifanayo sokwengezwa, ukucoleka kokucoleka, kuba ngcono umphumela wokugcina amanzi.

Ukugcinwa kwamanzi kwe-HPMC nakho kuhlobene nezinga lokushisa elisetshenzisiwe, futhi ukugcinwa kwamanzi kwe-methyl cellulose ether kuncipha ngokunyuka kwezinga lokushisa. Kodwa-ke, ekusetshenzisweni kwezinto ezibonakalayo, i-powder mortar eyomile ivame ukusetshenziswa kuma-substrates ashisayo emazingeni okushisa aphezulu (angaphezu kwama-degrees angu-40) ezindaweni eziningi, njengokuphahlekwa kwe-putty yangaphandle ngaphansi kwelanga ehlobo, okuvame ukusheshisa Ukuphulukiswa kukasimende kanye nokuqina kukasimende. udaka olomile. Ukwehla kokugcinwa kwamanzi kuye kwaholela embonweni ocacile wokuthi kokubili ukusebenza nokumelana nokuqhekeka kuyathinteka, futhi kubaluleke kakhulu ukunciphisa umthelela wezici zokushisa ngaphansi kwezimo ezinjalo. Nakuba isithako se-methyl hydroxyethyl cellulose ether njengamanje sithathwa njengesihamba phambili ekuthuthukisweni kobuchwepheshe, ukuncika kwaso kumazinga okushisa kusengaholela ekwenzeni buthaka ukusebenza kodaka olomile. Nakuba inani le-methyl hydroxyethyl cellulose (ifomula yasehlobo) lenyukile, ukusebenza kahle nokumelana nokuqhekeka akukakwazi ukuhlangabezana nezidingo zokusetshenziswa. Ngokusebenzisa ezinye izindlela zokwelapha ezikhethekile, ezinjengokukhulisa izinga le-etherification, i-MC ingagcina umphumela wayo wokugcina amanzi ungcono emazingeni okushisa aphakeme, ukuze inikeze ukusebenza okungcono ngaphansi kwezimo ezinzima.


Isikhathi sokuthumela: Oct-20-2022
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