Cellulose ether mune simenti yakagadzirwa zvigadzirwa

Cellulose ether imhando yezvakawanda zvekuwedzera izvo zvinogona kushandiswa muzvigadzirwa zvesimende. Iri bepa rinounza kemikari yemethyl cellulose (MC) uye hydroxypropyl methyl cellulose (HPMC /) inowanzoshandiswa muzvigadzirwa zvesimende, nzira uye musimboti wemhinduro yemambure uye hunhu hukuru hwemhinduro. Kudzikira kwe tembiricha yekupisa gel uye viscosity mune zvigadzirwa zvesimende zvakakurukurwa zvichibva pane inoshanda yekugadzira ruzivo.

Mazwi akakosha:cellulose ether; Methyl cellulose;Hydroxypropyl methyl cellulose; Kupisa gel tembiricha; viscosity

1. Muchidimbu

Cellulose ether (CE yepfupi) inogadzirwa ne cellulose kuburikidza ne etherification reaction yeimwe kana akati wandei etherifying ejenti uye yakaoma kugaya. CE inogona kukamurwa kuita ionic uye isiri-ionic mhando, pakati peiyo isiri-ionic mhando CE nekuda kweiyo yakasarudzika yekupisa gel maitiro uye solubility, munyu kuramba, kupisa kupisa, uye ine yakakodzera pamusoro pekuita. Inogona kushandiswa semvura inochengetedza mumiriri, kumiswa mumiriri, emulsifier, firimu rekugadzira agent, lubricant, adhesive uye rheological kunatsiridza. Nzvimbo huru dzekushandisa kune dzimwe nyika ndeye latex coatings, zvekuvaka, kuchera mafuta uye zvichingodaro. Zvichienzaniswa nenyika dzekunze, kugadzirwa uye kushandiswa kweEC-soluble CE kuchiri kutanga. Nekuvandudzwa kwehutano hwevanhu uye ruzivo rwezvakatipoteredza. Mvura-inonyungudika CE, iyo isingakuvadzi kune physiology uye isingasvibise nharaunda, ichave nebudiriro huru.

Mumunda wezvivakwa zvekuvaka zvinowanzo sarudzwa CE ndeye methyl cellulose (MC) uye hydroxypropyl methyl cellulose (HPMC), inogona kushandiswa sependi, plaster, dhaka uye simende zvigadzirwa plasticizer, viscosifier, mvura yekuchengetedza mumiriri, mhepo intraining agent uye retarding agent. Yakawanda yeindasitiri yezvivakwa zvekuvaka inoshandiswa pakupisa kwakajairika, uchishandisa mamiriro akaoma musanganiswa poda nemvura, isingabatanidzi hunhu hwekunyungudika uye inopisa gel maitiro eEC, asi mukugadzirwa kwemakanika kwesimende zvigadzirwa uye mamwe akakosha tembiricha mamiriro. CE ichaita basa rakazara.

2. Chemical properties ye CE

CE inowanikwa nekurapa cellulose kuburikidza nenhevedzano yemakemikari uye emuviri nzira. Zvinoenderana neyakasiyana kemikari inotsiva chimiro, kazhinji inogona kukamurwa kuita: MC, HPMC, hydroxyethyl cellulose (HEC), nezvimwe. Mukugadzira CE, cellulose fibers dzinotanga kudziyiswa mumushonga we alkaline wozobatwa ne etherifying agents. Zvigadzirwa zvefibrous reaction zvinocheneswa uye kutswanywa kuita hupfu hwakafanana hwehumwe hunyoro.

Maitiro ekugadzira eMC anongoshandisa methane chloride se etherifying agent. Pamusoro pekushandiswa kwemethane chloride, kugadzirwa kweHPMC kunoshandisawo propylene oxide kuwana hydroxypropyl substituent mapoka. Yakasiyana CE ine akasiyana methyl uye hydroxypropyl inotsiva mareti, ayo anokanganisa kugarisana kwe organic uye tembiricha ye gel yeEC mhinduro.

Huwandu hwemapoka eChitsiviso pane akapererwa neglucose structural units ye cellulose inogona kuratidzwa nepercent yehuwandu kana avhareji yenhamba yemapoka ekutsiva (kureva, DS - Degree of Substitution). Huwandu hwemapoka anotsiva hunotaridza zvimiro zveEC zvigadzirwa. Mhedzisiro yeavhareji dhigirii yekutsiva pane solubility yezvigadzirwa etherification ndeiyi inotevera:

(1) low substitution degree inonyungudika mulye;

(2) mwero wakakwirira zvishoma wekutsiva unonyungudika mumvura;

(3) dhigirii yakakwirira yekutsiva yakanyungudika mu polar organic solvents;

(4) Dhigirii yepamusoro yekutsiva yakanyungudika mune isiri-polar organic solvents.

3. Disolution nzira ye CE

CE ine yakasarudzika solubility pfuma, kana tembiricha yakwira kusvika kune imwe tembiricha, haina kunyungudika mumvura, asi pazasi tembiricha iyi, kunyungudika kwayo kuchawedzera nekudzikira kwekushisa. CE inonyungudika mumvura inotonhora (uye mune dzimwe nguva mune chaiyo organic solvents) kuburikidza nekuita kwekuzvimba uye hydration. CE mhinduro hadzina zviri pachena solubility zvimisikidzo zvinoonekwa mukunyungudutswa kweionic munyu. Iko kusungirirwa kweEC kunowanzo kugumira kune viscosity iyo inogona kudzorwa nemidziyo yekugadzira, uye zvakare inosiyana zvichienderana nekuona uye makemikari akasiyana anodiwa nemushandisi. Iyo mhinduro yekumisikidza yakaderera viscosity CE kazhinji 10% ~ 15%, uye yakakwira viscosity CE kazhinji inogumira ku2% ~ 3%. Mhando dzakasiyana dzeEC (zvakadai sehupfu kana pasi yakabatwa hupfu kana granular) inogona kukanganisa magadzirirwo emhinduro.

3.1 CE pasina kurapwa kwepamusoro

Kunyangwe CE ichinyungudika mumvura inotonhora, inofanirwa kuparadzirwa zvachose mumvura kudzivirira kudhumhana. Mune zvimwe zviitiko, yekumhanyisa musanganiswa kana funnel inogona kushandiswa mumvura inotonhora kuparadzira CE poda. Zvisinei, kana hupfu husina kucheneswa hukaiswa zvakananga mumvura inotonhora pasina kunyatsokuchidzira, mapundu makuru anoumba. Chikonzero chikuru chekukaka ndechekuti iyo CE poda zvimedu hazvina kunyorova zvachose. Kana chikamu chimwe chete chehupfu chinopera, firimu yegel ichaumbwa, iyo inodzivirira poda yakasara kubva pakuramba ichinyunguduka. Naizvozvo, isati yaparara, iyo CE particles inofanira kuparadzirwa zvizere sezvinobvira. Nzira mbiri dzinotevera dzekuparadzira dzinowanzoshandiswa.

3.1.1 Dry mix dispersion method

Iyi nzira inonyanya kushandiswa muzvigadzirwa zvesimende. Usati wawedzera mvura, sanganisa imwe poda neEC poda zvakaenzana, kuti CE poda zvimedu zviparadzirwe. Minimum kusanganisa ratio: Humwe hupfu: CE hupfu =(3 ~ 7): 1.

Munzira iyi, kupararira kweEC kunopedzwa munzvimbo yakaoma, uchishandisa imwe hupfu sepakati kuparadzira zvimedu zveEC kune mumwe nemumwe, kuitira kudzivirira kubatana kweEC zvimedu pakuwedzera mvura uye kukanganisa kumwe kuparara. Nokudaro, mvura inopisa haidiwi kupararira, asi chiyero chekuparara chinoenderana nehupfu hwehupfu uye mamiriro ezvinhu anokurudzira.

3.1.2 Nzira yekuparadzira mvura inopisa

(1) Yekutanga 1/5 ~ 1/3 yekudziya kwemvura inodiwa kusvika 90C pamusoro, wedzera CE, wobva wazunguza kusvika zvimedu zvese zvapararira zvakanyorova, uyezve mvura yakasara mumvura inotonhora kana yechando yawedzerwa kuderedza tembiricha. mhinduro, yakambosvika pakushisa kweEC CE, hupfu hwakatanga hydrate, viscosity yakawedzera.

(2) Unogonawo kupisa mvura yese, wobva wawedzera CE kubvongodza uchitonhodza kusvika hydration yapera. Kutonhodza kwakakwana kwakakosha kune yakakwana hydration yeEC uye kuumbwa kwe viscosity. Kuti uwane viscosity yakanaka, MC mhinduro inofanirwa kutonhodzwa kusvika 0 ~ 5 ℃, nepo HPMC ichingoda kutonhodzwa kusvika 20 ~ 25 ℃ kana pazasi. Sezvo kuzara kwemvura kunoda kutonhora kwakakwana, mhinduro dzeHPMC dzinowanzo shandiswa uko mvura inotonhora isinga shandiswe: zvinoenderana neruzivo, HPMC ine tembiricha yekudzikisira pane MC pazasi tembiricha kuti iwane viscosity yakafanana. Zvakakosha kucherechedza kuti nzira yekuparadzira mvura inopisa inongoita kuti CE zvimedu zvipararire zvakaenzana patembiricha yepamusoro, asi hapana mhinduro inogadzirwa panguva ino. Kuti uwane mhinduro neimwe viscosity, inofanira kutonhodzwa zvakare.

3.2 Pamusoro yakarapwa dispersible CE poda

Muzviitiko zvakawanda, CE inodiwa kuve nezvose zvinorasika uye nekukurumidza hydration (kugadzira viscosity) hunhu mumvura inotonhora. Iyo yepamusoro inorapwa CE inonyungudika kwenguva pfupi mumvura inotonhora mushure mekurapa kwakakosha kemikari, iyo inovimbisa kuti kana CE yawedzerwa kumvura, haizobva yagadzira viscosity yakajeka uye inogona kuparadzirwa pasi pemamiriro mashoma eshear simba. Iyo "nguva yekunonoka" ye hydration kana viscosity kuumbwa mhedzisiro yekubatanidzwa kweiyo dhigirii yekurapa kwepamusoro, tembiricha, pH yehurongwa, uye CE mhinduro yekumisikidza. Kunonoka kwe hydration kunowanzo kuderedzwa pamazinga epamusoro, tembiricha, uye pH mazinga. Muzhinji, zvisinei, kuwanda kweEC hakutariswe kudzamara yasvika 5% (chiyero chemvura).

Kuti uwane mhedzisiro yakanaka uye yakakwana hydration, iyo inobatwa neEC inofanira kusimudzwa kwemaminitsi mashoma pasi pemamiriro asina kwaakarerekera, ine pH kubva pa8.5 kusvika 9.0, kusvika iyo yakanyanya viscosity yasvika (kazhinji maminitsi gumi-30). Kana iyo pH yachinja kuva yakakosha (pH 8.5 kusvika 9.0), iyo yepamusoro inobatwa CE inonyungudika zvachose uye nekukurumidza, uye mhinduro inogona kugadzikana papH 3 kusvika 11. Zvisinei, zvakakosha kuziva kuti kugadzirisa pH yehuwandu hwehuwandu hwemashoko. ichaita kuti viscosity ive yakanyanya kukwira pakupomba nekudurura. Iyo pH inofanirwa kugadziridzwa mushure mekunge slurry yadzikiswa kune yaidiwa.

Kupfupisa, iyo yekumisa maitiro eEC inosanganisira maviri maitiro: kupararira kwemuviri uye kuparara kwemakemikari. Chinokosha ndechekuparadzira zvimedu zveEC kune imwe neimwe isati yanyungudutswa, kuitira kuti udzivise kusanganiswa nekuda kwepamusoro viscosity panguva yakaderera tembiricha kunyungudika, izvo zvinozokanganisa kuwedzera kunyungudika.

4. Zvinhu zveEC solution

Mhando dzakasiyana dzeEC aqueous mhinduro dzinoita gelate patembiricha yavo chaiyo. Iyo gel inogadziriswa zvachose uye inoumba mhinduro kana yatonhodzwa zvakare. Iyo inodzoreredza thermal gelation yeEC yakasarudzika. Muzvigadzirwa zvakawanda zvesimende, kushandiswa kukuru kweiyo viscosity yeEC uye inowirirana kuchengetedza mvura uye lubrication zvivakwa, uye viscosity uye tembiricha yegel ine hukama hwakananga, pasi petembiricha yegel, yakadzika tembiricha, yakakwira viscosity yeEC. zviri nani iyo inoenderana nekuchengetedza mvura kuita.

Tsananguro yazvino yechiitiko chegel ndeichi: mukuparara, izvi zvakafanana.

Mapolymer molecules eshinda anobatana nemvura molecular layer, zvichikonzera kuzvimba. Mamorekuru emvura anoita semafuta ekuzora, anogona kukwevera necheni refu dzepolymer mamorekuru, kuitira kuti mhinduro yacho ive nehunhu hwemvura inopenya iri nyore kurasa. Kana tembiricha yemushonga ichiwedzera, cellulose polymer zvishoma nezvishoma inorasikirwa nemvura uye viscosity yemushonga inoderera. Kana iyo gel point yasvika, iyo polima inopera zvachose, zvichikonzera kubatana pakati pemapolymers uye kuumbwa kwegel: simba rejeri rinoramba richiwedzera sezvo tembiricha inoramba iri pamusoro peiyo gel point.

Sezvo mhinduro inotonhora, gel rinotanga kutendeuka uye viscosity inoderera. Pakupedzisira, viscosity yemhinduro yekutonhora inodzokera kune yekutanga tembiricha yekukwira curve uye inowedzera nekudzikira kwekushisa. Mhinduro yacho inogona kutonhodzwa kune yayo yekutanga viscosity kukosha. Naizvozvo, iyo yekupisa gel process yeEC inodzokororwa.

Basa guru reEC muzvigadzirwa zvesimende ndere viscosifier, plasticizer uye yekuchengetedza mvura, saka maitiro ekudzora viscosity uye tembiricha yegel yave chinhu chakakosha muzvigadzirwa zvesimende zvinowanzo shandisa yekutanga tembiricha yegel pazasi pechikamu che curve. saka iyo yakadzikira tembiricha, iyo yakakwira viscosity, zvakanyanya kujeka mhedzisiro yeviscosifier yekuchengetedza mvura. Mhedzisiro yemhedzisiro yeextrusion simende bhodhi yekugadzira mutsara inoratidzawo kuti iyo yakadzika tembiricha yezvinhu iri pasi pezvakafanana zveEC, zvirinani viscosification uye kuchengetedza mvura. Sezvo simende sisitimu iri yakanyanya kuomarara muviri uye makemikari zvivakwa system, pane zvakawanda zvinhu zvinokanganisa shanduko yeEC gel tembiricha uye viscosity. Uye pesvedzero yeakasiyana siyana eTaianin maitiro uye dhigirii haana kufanana, saka iyo inoshanda application yakaonawo kuti mushure mekusanganisa simende system, iyo chaiyo gel tembiricha yeEC (ndiko kuti, glue uye mvura kuchengetedza mhedzisiro inodzikira zviri pachena pakupisa uku. ) yakaderera pane tembiricha yegel inoratidzwa nechigadzirwa, saka, mukusarudzwa kweEC zvigadzirwa kufunga nezve izvo zvinokonzeresa tembiricha yegel. Izvi zvinotevera zvinhu zvikuru zvatinotenda zvinokanganisa viscosity uye tembiricha yegel yeEC mhinduro mune zvigadzirwa zvesimende.

4.1 Kufurira pH kukosha pane viscosity

MC uye HPMC haisi-ionic, saka viscosity yemhinduro kupfuura viscosity yeionic glue yakasikwa ine hupamhi hweDH kugadzikana, asi kana pH inokosha inopfuura 3 ~ 11, ivo vachaderedza zvishoma nezvishoma viscosity pane imwe nzvimbo. tembiricha yepamusoro kana mukuchengetedza kwenguva yakareba, kunyanya yakakwira viscosity mhinduro. Iyo viscosity yeEC chigadzirwa mhinduro inodzikira muasidhi yakasimba kana yakasimba base solution, iyo inonyanya kukonzerwa nekuderera kwemvura kweEC kunokonzerwa nebase uye asidhi. Naizvozvo, iyo viscosity yeEC inowanzo dzika kusvika kune imwe nhanho munzvimbo yealkaline yezvigadzirwa zvesimende.

4.2 Kupesvedzera kweyero yekudziya uye kubvongodza pane gel process

Iyo tembiricha ye gel point inokanganiswa neyakasanganiswa mhedzisiro yekudziya mwero uye inosimudzira shear rate. Kumhanyisa kumhanyisa uye nekukurumidza kupisa kunowanzo wedzera tembiricha yegel zvakanyanya, iyo yakanakira zvigadzirwa zvesimende zvinogadzirwa nemakanika kusanganisa.

4.3 Pesvedzero yekuisa pfungwa pane inopisa gel

Kuwedzera kusangana kwemhinduro kunowanzo kudzikisa tembiricha yegel, uye gel mapoinzi eyakaderera viscosity CE akakwira kupfuura ayo epamusoro viscosity CE. Zvakadai seDOW's METHOCEL A

Iyo tembiricha yegel inodzikiswa ne10 ℃ kune yega yega 2% kuwedzera mukusangana kwechigadzirwa. Kuwedzera kwe2% muhuwandu hwezvigadzirwa zvemhando yeF kunoderedza tembiricha yegel ne4 ℃.

4.4 Kufurira kwezvinowedzera pane thermal gelation

Mumunda wezvivakwa zvekuvaka, zvakawanda zvekushandisa inorganic munyu, izvo zvichave zvine chekuita nekushisa kwegel kweEC solution. Zvichienderana nekuti iyo yekuwedzera iri kuita se coagulant kana solubilizing agent, zvimwe zvinowedzera zvinogona kuwedzera tembiricha yekupisa gel yeEC, nepo zvimwe zvinogona kuderedza tembiricha yegel yeEC: semuenzaniso, solvent-enhancing ethanol, PEG-400 (polyethylene glycol) , anediol, nezvimwewo, inogona kuwedzera gel point. Minyu, glycerin, sorbitol uye zvimwe zvinhu zvinoderedza gel point, isiri-ionic CE kazhinji haizodzivirirwe nekuda kweiyo polyvalent simbi ions, asi kana iyo electrolyte concentration kana zvimwe zvinhu zvakanyungudutswa zvakapfuura imwe muganhu, CE zvigadzirwa zvinogona kuiswa munyu kunze. mhinduro, izvi zvinokonzerwa nemakwikwi e electrolytes kumvura, zvichikonzera kudzikiswa kwe hydration yeEC, Munyu wemugadziriso wechigadzirwa cheEC unowanzo kukwira zvishoma pane icho cheMc chigadzirwa, uye munyu unosiyana zvishoma. mune dzakasiyana HPMC.

Zvizhinji zvinongedzo muzvigadzirwa zvesimende zvinogadzira iyo gel point yeEC kudonha, saka kusarudzwa kwezvinowedzera kunofanirwa kufunga kuti izvi zvinogona kukonzera iyo gel point uye viscosity yeEC shanduko.

5. Mhedziso

(1) cellulose ether is natural cellulose kuburikidza ne etherification reaction, ine yakakosha structural unit ye ​​dehydrated glucose, zvichienderana nerudzi uye nhamba yemapoka anotsiva panzvimbo yayo yekutsiva uye ine zvinhu zvakasiyana. Iyo isiri-ionic ether yakadai seMC uye HPMC inogona kushandiswa se viscosifier, mumiriri wekuchengetedza mvura, mumiriri wemhepo uye zvimwe zvinoshandiswa zvakanyanya muzvigadzirwa zvezvinhu zvekuvaka.

(2) CE ine yakasarudzika solubility, inogadzira mhinduro pane imwe tembiricha (senge tembiricha yegel), uye kugadzira yakasimba gel kana solid particle musanganiswa pakupisa kwegel. Nzira huru dzekunyungudutsa dzakaoma kusanganisa nzira yekuparadzira, nzira yekuparadzira mvura inopisa, nezvimwewo, muzvigadzirwa zvesimende zvinowanzo shandiswa yakaoma kusanganisa nzira yekuparadzira. Kiyi ndeyekuparadzira CE zvakaenzana isati yanyungudika, ichigadzira mhinduro pane yakaderera tembiricha.

(3) Kugadziriswa kwekugadzirisa, tembiricha, pH kukosha, kemikari yezvinowedzera uye inomhanyisa chiyero inokanganisa tembiricha yegel uye viscosity yeEC mhinduro, kunyanya zvigadzirwa zvesimende zvigadziriso zvemunyu mune alkaline nharaunda, kazhinji inoderedza tembiricha yegel uye viscosity yeEC solution. , zvichiunza migumisiro yakaipa. Nokudaro, maererano nemaitiro eEC, kutanga, inofanira kushandiswa pakupisa kwakadzika (pasi pekushisa kwegel), uye chechipiri, simba rekuwedzera rinofanira kuverengwa.