Hydroxypropyl Methyl Cellulose Ether Technology

Hydroxypropyl methyl cellulose ether ke mofuta oa nonpolar cellulose ether e qhibilihang ka metsing a batang e fumanoang ho tsoa selulose ea tlhaho ka alkalization le etherification modification.

Mantsoe a sehlooho:hydroxypropyl methylcellulose ether; karabelo ea alkalization; karabelo ea etherification

1. Theknoloji

Selulose ea tlhaho ha e qhibilihe ka metsing le ka metsoako ea lintho tse phelang, e tsitsitseng ho leseli, mocheso, acid, letsoai le mecha ea litaba ea lik'hemik'hale, 'me e ka kolobisoa ka tharollo ea alkali e hlapollang ho fetola bokaholimo ba selulose.

Hydroxypropyl methyl cellulose ether ke mofuta oa ether e seng polar, e qhibilihang ka metsing a batang e qhibilihang ka har'a selulose ea tlhaho ka alkalization le etherification modification.

2. Mokhoa o ka sehloohong oa karabelo ea lik'hemik'hale

2.1 Karabelo ea alkalization

Ho na le menyetla e 'meli ea karabelo ea cellulose le sodium hydroxide, ke hore, ho ea ka maemo a fapaneng a ho hlahisa metsoako ea limolek'hule, R - OH - NaOH; kapa ho hlahisa metsoako ea joala ea tšepe, R – ONa.

Litsebi tse ngata li lumela hore cellulose e sebetsana le alkali e tsitsitseng ho etsa ntho e tsitsitseng, 'me e nahana hore sehlopha ka seng kapa tse peli tsa glucose li kopantsoe le molek'hule e le' ngoe ea NaOH (sehlopha se le seng sa tsoekere se kopantsoe le limolek'hule tse tharo tsa NaOH ha karabelo e felile).

C6H10O5 + NaOH→C6H10O5 NaOH kapa C6H10O5 + NaOH→C6H10O4 ONa + H2O

C6H10O5 + NaOH→(C6H10O5 ) 2 NaOH kapa C6H10O5 + NaOH→C6H10O5 C6H10O4 ONa + H2O

Haufinyane tjena, litsebi tse ling li lumela hore tšebelisano pakeng tsa selulose le alkali e tsitsitseng e tla ba le liphello tse peli ka nako e le 'ngoe.

Ho sa tsotelehe sebopeho, ts'ebetso ea lik'hemik'hale ea selulose e ka fetoloa kamora ts'ebetso ea cellulose le alkali, mme e ka sebetsana le mecha ea litaba ea lik'hemik'hale e fapaneng ho fumana mefuta e nang le moelelo.

2.2 Karabelo ea Etherification

Kamora 'alkalization, selulose e sebetsang ea alkali e kopana le etherification ho etsa cellulose ether. Lintho tse etherifying tse sebelisoang ke methyl chloride le propylene oxide.

Sodium hydroxide e sebetsa joalo ka mokelikeli.

n le m li emela tekanyo ea ho kenya hydroxypropyl le methyl sebakeng sa cellulose, ka ho latellana. Kakaretso e kholo ea m + n ke 3.

Ntle le karabelo e kholo e boletsoeng ka holimo, ho boetse ho na le litlamorao:

CH2CH2OCH3 + H2O→HOCH2CH2OHCH3

CH3Cl + NaOH→CH3OH + NaCl

3. Tlhaloso ea ts'ebetso ea hydroxypropyl methylcellulose ether

Ts'ebetso ea hydroxypropyl methyl cellulose ether ("cellulose ether" ka nako e khuts'oane) e entsoe ka mekhoa ea 6, e leng: ho senya thepa e tala, (alkalinization) etherification, ho tlosoa ha solvent, filtration le ho omisa, ho senya le ho kopanya, le ho qeta ho paka sehlahisoa.

3.1 Tokiso ea thepa e tala

Selulose e khuts'oane ea tlhaho e rekiloeng 'marakeng e siloa hore e be phofo ke pulverizer ho nolofatsa ts'ebetso e latelang; alkali e tiileng (kapa alkali ea metsi) e qhibilihisoa ebe e lokisoa, 'me e futhumatsoa hoo e ka bang 90°C ho etsa 50% caustic soda tharollo bakeng sa tšebeliso. Lokisetsa reaction methyl chloride, propylene oxide etherification agent, isopropanol le toluene reaction solvent ka nako e le 'ngoe.

Ho phaella moo, mokhoa oa ho itšoara o hloka lisebelisoa tse thusang tse kang metsi a chesang le metsi a hloekileng; mouoane, metsi a pholileng a mocheso o tlase, le metsi a pholileng a potolohang a hlokahala ho thusa matla.

Li-linter tse khutšoane, methyl chloride, le li-agent tsa propylene oxide etherification ke tsona lisebelisoa tse ka sehloohong tsa ho hlahisa cellulose ea etherified, 'me li-linter tse khutšoane li sebelisoa ka bongata. Methyl chloride le propylene oxide li kenya letsoho karabelong e le lisebelisoa tsa etherification ho fetola cellulose ea tlhaho, palo ea ts'ebeliso ha e kholo.

Li-solvents (kapa li-diluents) haholo-holo li kenyelletsa toluene le isopropanol, tseo ha e le hantle li sa jeoang, empa ka lebaka la tahlehelo e kentsoeng le e fokolang, ho na le tahlehelo e fokolang ea tlhahiso, 'me chelete e sebelisoang e nyenyane haholo.

Ts'ebetso ea ho lokisa thepa e tala e na le sebaka sa tanka ea thepa e tala le ntlo ea polokelo ea thepa e kentsoeng. Li-etherifying agents le solvents, tse kang toluene, isopropanol, le acetic acid (tse sebelisetsoang ho fetola boleng ba pH ea li-reactants), li bolokiloe sebakeng sa tanka e tala. Phepelo ea lint e khutšoanyane e lekane , e ka fanoa ke 'maraka ka nako leha e le efe.

Letlapa le lekhutšoane le pshatlehileng le romelloa ho workshop ka kariki bakeng sa ho sebelisoa.

3.2 (Alkalinization) etherification

(Alkaline) etherification ke ts'ebetso ea bohlokoa ts'ebetsong ea etherification ea selulose. Mokhoeng oa pele oa tlhahiso, mekhoa ea mehato e 'meli e ile ea etsoa ka thoko. Hona joale ts'ebetso e ntlafalitsoe, 'me mehato ea mehato e' meli e kopantsoe sethaleng se le seng ebe e etsoa ka nako e le 'ngoe.

Ntlha ea pele, hloekisa tanka ea etherification ho tlosa moea, ebe u e nkela sebaka ka naetrojene ho etsa hore tanka e hloke moea. Eketsa tharollo e lokiselitsoeng ea sodium hydroxide, eketsa palo e itseng ea isopropanol le toluene solvent, qala ho hlohlelletsa, ebe u eketsa boea bo bokhutšoane ba k'hothone, ho bulela metsi a potolohang ho pholile, 'me ka mor'a hore mocheso o theohe ho isa boemong bo itseng, bulela ho theola tlaase. mocheso oa metsi ho theola mocheso oa thepa ea sistimi E theohela ho hoo e ka bang 20℃, le ho boloka karabelo nako e itseng ea nako ho qeta alkalization.

Kamora alkalization, eketsa etherifying agent methyl chloride le propylene oxide e lekantsoeng ke tanka ea metering e phahameng, tsoela pele ho qala ho sisinyeha, sebelisa mouoane ho phahamisa mocheso oa sistimi ho hoo e ka bang 70.℃~ 80℃, ebe o sebelisa metsi a chesang ho tsoela pele ho futhumatsa le ho boloka Mocheso oa karabelo o laoloa, ebe mocheso oa karabelo le nako ea ho itšoara li laoloa, 'me ts'ebetso e ka phethoa ka ho susumetsa le ho kopanya ka nako e itseng.

Karabelo e etsoa hoo e ka bang 90°C le 0.3 MPa.

3.3 Pheliso

Lisebelisoa tse boletsoeng ka holimo tsa ts'ebetso li romelloa ho desolventizer, 'me lisebelisoa lia tlosoa ebe li futhumatsoa ka mouoane,' me li-solvents tsa toluene le isopropanol li fetoha mouoane ebe li khutlisetsoa hape bakeng sa ho tsosolosoa.

Mokelikeli oa mouoane o qala ho pholile ebe o koaheloa ka mokhoa o itseng ka metsi a potolohang, ebe o koaheloa ka metsi a mocheso o tlaase, 'me motsoako oa condensate o kena mokelikeli le karohano ho arola metsi le solvent. Motsoako o motsoako oa toluene le isopropanol karolong e ka holimo e lokisoa ka tekanyo. E sebelise ka ho toba, 'me u khutlisetse tharollo ea metsi le isopropanol karolong e ka tlaase ho desolventizer bakeng sa tšebeliso.

Eketsa acetic acid ho reactant ka mor'a desolation ho neutralize feteletseng sodium hydroxide, joale sebelisa metsi a chesang ho hlatsoa thepa, sebelisa ka botlalo coagulation tšobotsi ea selulose ether ho metsi a chesang ho hlatsoa selulose ether, le ho hloekisa reactant. Lisebelisoa tse hloekisitsoeng li romelloa ts'ebetsong e latelang bakeng sa ho arohana le ho omisa.

3.4 Sefa le ho omisa

Thepa e hloekisitsoeng e romelloa ho "screw separator" e otlolohileng ka pompo ea "screw screw pump" ho arola metsi a mahala, 'me lintho tse setseng tse tiileng li kena ka har'a mochini o omisang moea, ebe li omisoa ha li kopana le moea o chesang, ebe li feta leholiotsoana. karohano le moea Karohano, thepa e tiileng e kena ho silakanya ho latelang.

Metsi a arohaneng ke separator se rapameng a kena ka tanka ea ho hloekisa metsi ka mor'a hore ho be le sedimentation ka tanka ea sedimentation ho arola selulose e kentsoeng.

3.5 Ho pshatla le ho kopanya

Ka mor'a ho omisa, selulose ea etherified e tla ba le boholo bo sa lekaneng ba likaroloana, tse lokelang ho silafatsoa le ho tsoakana e le hore kabo ea boholo ba likaroloana le ponahalo ea kakaretso ea thepa e fihlelle litlhoko tsa maemo a sehlahisoa.

3. 6 Ho qeta ho paka sehlahisoa

Thepa e fumanoang ka mor'a ho senya le ho kopanya ts'ebetso ke cellulose e phethiloeng ea etherified, e ka pakoang le ho kenngoa polokelong.

4. Kakaretso

Metsi a litšila a arohaneng a na le tekanyo e itseng ea letsoai, haholo-holo sodium chloride. Metsi a litšila a fetoha mouoane ho arola letsoai, 'me mouoane oa bobeli o mouoane o ka koaheloa ho khutlisa metsi a koalehileng, kapa a ntšoa ka kotloloho. Karolo e ka sehloohong ea letsoai le arohaneng ke sodium chloride, eo hape e nang le palo e itseng ea sodium acetate ka lebaka la ho se nke lehlakore ka acetic acid. Letsoai lena le na le boleng ba tšebeliso ea indasteri feela ka mor'a ho tsosolosa, ho arohana le ho hloekisa.