Hydroxypropyl Methyl Cellulose Ether Hangarau

Ko te Hydroxypropyl methyl cellulose ether he ahua o te etera cellulose nonpolar ka whakarewahia i roto i te wai matao i riro mai i te cellulose taiao ma te whakarereketanga me te whakarereketanga.

Kupumatua:hydroxypropyl methylcellulose ether; tauhohenga waikawa; tauhohenga etherification

1. Hangarau

Ko te cellulose taiao he kore e rewa i roto i te wai me nga whakarewa pararopi, e mau ana ki te marama, ki te wera, ki te waikawa, ki te tote me etahi atu papaa matū, ka taea te whakamakuku ki te wairewa alkali waimeha hei huri i te mata o te cellulose.

Ko te Hydroxypropyl methyl cellulose ether he momo kore-polar, matao wai-wairewa cellulose etera i riro mai i te cellulose taiao na roto i te whakarereketanga me te whakarereketanga.

2. Te tātai tauhohenga matū matua

2.1 Tauhohenga waikore

E rua nga waahanga mo te tauhohenga o te cellulose me te konutai waikawa, ara, i runga i nga tikanga rereke hei whakaputa i nga pūhui ngota, R - OH - NaOH; ki te whakaputa pūhui waipiro whakarewa, R – ONa.

Ko te nuinga o nga tohunga e whakapono ana ka tauhohe te cellulose me te kawakawa kawa ki te hanga i tetahi matū pumau, me te whakaaro ka honohia ia, e rua ranei nga roopu huka ki tetahi ngota ngota NaOH (kotahi roopu huka ka honoa ki nga ngota ngota NaOH e toru ina oti te tauhohenga).

C6H10O5 + NaOH→C6H10O5 NaOH or C6H10O5 + NaOH→C6H10O4 ONa + H2O

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

Ina tata nei, e whakapono ana etahi tohunga ka rua nga paanga o te taunekeneke i waenga i te cellulose me te alkali kawa i te wa kotahi.

Ahakoa te hanganga, ka taea te whakarereke i te mahi matū o te cellulose i muri i te mahi a te cellulose me te alkali, a ka taea e ia te tauhohe me nga momo matū matū kia whiwhi momo whai kiko.

2.2 Tauhohenga whakaetere

Whai muri i te whakamaaramatanga, ka tauhohe te cellulose alkali kaha me te kaihoko eterification hei hanga i te cellulose ether. Ko nga mea whakaetere e whakamahia ana ko te methyl chloride me te propylene oxide.

Ka mahi te konutai wai hei whakakorikori.

Ko te n me te m e tohu ana i te tohu whakakapinga o te hydroxypropyl me te methyl ki te waeine cellulose. Ko te tapeke mōrahi o te m + n he 3.

I tua atu i te tauhohenga matua kua whakahuahia ake nei, kei reira ano nga tauhohenga taha:

CH2CH2OCH3 + H2O→HOCH2CH2OHCH3

CH3Cl + NaOH→CH3OH + NaCl

3. Tukatuka whakaahuatanga o te hydroxypropyl methylcellulose ether

Ko te tukanga o te hydroxypropyl methyl cellulose ether ("cellulose ether" mo te poto) e 6 nga tukanga, ara: te kuru i nga rawa mata, (te whakawhanaunga) etherification, te tango whakarewa, te filtration me te whakamaroke, te kuru me te whakaranu, me te kapi hua kua oti.

3.1 Te whakarite rauemi mata

Ko te cellulose poto-poto taiao e hokona ana i te maakete ka pakaruhia ki te paura e te pulverizer hei whakahaere i nga mahi o muri mai; ka rewa te kawakawa totoka (he kawakawa wai ranei) ka rite, ka whakamahana ki te 90 pea°C ki te hanga 50 % wairewa houra kaipahua hei whakamahi. Whakaritea te tauhohenga methyl chloride, propylene oxide etherification agent, isopropanol me toluene tauhohe whakarewa i te wa ano.

I tua atu, ko te tukanga urupare e hiahia ana ki nga taonga awhina penei i te wai wera me te wai parakore; Ko te mamaoa, ko te wai whakamahana iti-mahana, me te wai whakamatao huri haere hei awhina i te hiko.

Ko nga linters poto, te methyl chloride, me te propylene oxide etherification agents ko nga mea matua mo te whakaputa cellulose etherified, a he nui te whakamahi i nga linters poto. Ko te Methyl chloride me te propylene oxide ka uru ki roto i te tauhohenga hei apiha whakaeera ki te whakarereke i te cellulose taiao, kaore te nui o te whakamahi.

Ko nga wairewa (he waimeha ranei) ko te toluene me te isopropanol, kaore i te pau, engari i runga i te ahua o nga ngaronga kua uru me te whakaheke, he iti te ngaronga o te mahi, he iti rawa te moni e whakamahia ana.

He waahi taika rawa me tetahi whare putunga rauemi mata kua piri. Ko nga mea whakakoi me nga whakarewa, penei i te toluene, te isopropanol, me te waikawa acetic (whakamahia hei whakatika i te uara pH o nga tauhohenga), ka rongoa ki roto i te waahi taika rawa. He rawaka te tuku o te lint poto, ka taea e te maakete te whakarato i nga wa katoa.

Ka tukuna atu ki te awheawhe me te kaata hei whakamahi.

3.2 (Alkalinization) etherification

Ko te whakamaaramatanga (Alkaline) he tukanga nui i roto i te tukanga o te etherification o te cellulose. I roto i te tikanga whakaputa o mua, ko nga tauhohenga e rua-taahiraa i mahia motuhake. Inaianei kua pai ake te mahi, a ka whakakotahihia nga tauhohenga e rua-taahiraa i te waahanga kotahi ka mahia i te wa kotahi.

Tuatahi, whakawetohia te tank etherification ki te tango i te hau, katahi ka whakakapi ki te hauota kia kore ai te tank i te hau. Tāpirihia te wairewa konutai waihā kua oti te whakarite, tāpirihia he wairewa isopropanol me toluene, tīmata te whakaoho, kātahi ka tāpirihia te wūru miro poto, whakakāhia te wai rere kia whakamatao, ā, ka heke te pāmahana ki tētahi taumata, whakakāhia te iti- te wai mahana ki te whakaheke i te pāmahana rauemi punaha Whakanohia ki te 20 pea℃, me te pupuri i te tauhohenga mo tetahi wa hei whakaoti i te whakamaaramatanga.

Whai muri i te whakamaaramatanga, taapirihia te methyl chloride etherifying agent me te propylene oxide i whangangahia e te tank ine taumata teitei, ka timata tonu te whakaoho, whakamahia te mamaoa hei hiki ake te pāmahana punaha ki te tata ki te 70℃~ 80℃, ka whakamahi i te wai wera kia mau tonu te whakamahana me te pupuri Ka whakahaerehia te paanga o te tauhohenga, katahi ka whakahaeretia te pāmahana tauhohenga me te wa tauhohenga, a ka taea te whakaoti i te mahi ma te whakaoho me te whakaranu mo tetahi waa.

Ka mahia te tauhohenga i te 90 pea°C me 0.3 MPa.

3.3 Whakakore

Ka tukuna atu nga rauemi tukatuka i runga ake nei ki te desolventizer, ka tihorea, ka whakamahanahia nga rauemi ki te mamaoa, ka whakaeto te toluene me te isopropanol solvents ka whakahokia mai mo te hangarua.

Ko te whakarewa whakaeto ka whakamatao i te tuatahi, ka whakamataohia tetahi waahanga ki te wai rere, katahi ka whakapoapoa ki te wai iti-mahana, ka uru te ranunga condensate ki te paparanga wai me te whakawehe hei wehe i te wai me te whakarewa. Ko te whakarewa whakauru o te toluene me te isopropanol i te paparanga o runga ka whakatikahia i roto i te waahanga. Whakamahia tika, ka whakahokia te wai me te wairewa isopropanol i te paparanga o raro ki te kaiwhakarewa hei whakamahi.

Taapirihia te waikawa acetic ki te reactant i muri i te whakakorenga hei whakakore i te taikaha konutai waikawa, katahi ka whakamahi i te wai wera hei horoi i nga rawa, kia whakamahia katoatia te ahua o te coagulation o te cellulose ether ki te wai wera hei horoi i te cellulose ether, me te whakamahine i te reactant. Ka tukuna nga mea parakore ki te tukanga e whai ake nei mo te wehenga me te whakamaroke.

3.4 Tātarihia ka whakamaroke

Ka tukuna nga mea kua oti te para ki te whakawehe wiri whakapae ma te pehanga teitei o te papu ki te wehe i te wai kore utu, a ko te toenga o nga mea totoka ka uru ki roto i te whakamaroke hau na roto i te kaiwhanga wiri, ka whakamarokehia ki te pa ki te hau wera, katahi ka haere ma te huripari. whakawehe me te rangi Wehewehenga, ka uru te rauemi totoka ki te kuru o muri.

Ko te wai i wehea e te whakawehe torino whakapae ka uru ki roto i te taika maimoatanga wai i muri i te parataiao i roto i te taika parataiao hei wehe i te cellulose kua mau.

3.5 Te kuru me te ranu

I muri i te whakamaroketanga, ka kore e rite te rahi o te matūriki o te cellulose etherified, me kuru me te konatunatua kia tutuki ai te tohatoha rahi matūriki me te ahua katoa o te rauemi ki nga whakaritenga paerewa hua.

3. 6 Kua oti te whakaemi hua

Ko nga mea i riro mai i muri i te kuru me te whakaranu i nga mahi ko te cellulose kua oti te whakahiato, ka taea te kii ka maka ki roto ki te rokiroki.

4. Whakarāpopototanga

Kei roto i te wai para kua wehea he tote, te nuinga o te konutai pūhaumāota. Ka whakaeto te wai para ki te wehe i te tote, a ka taea te whakakotono i te mamaoa tuarua kua whakaeto ki te whakahoki mai i te wai tote, ki te tuku tika ranei. Ko te waahanga matua o te tote kua wehea ko te konutai pūhaumāota, kei roto hoki te nui o te konutai acetate na te whakakorenga me te waikawa acetate. Ko tenei tote he uara whakamahi ahumahi anake i muri i te whakamaaramatanga, te wehenga me te purenga.