Hydroxypropyl methylcellulose (HPMC) chinhu chakakosha che cellulose derivative. Inoshandiswa zvakanyanya mukuvaka zvinhu nekuda kwekuchengetedza kwayo kwakanakisa kwemvura, kukora uye kugadzikana mukuvaka dhaka.
1. Chimiro chemakemikari uye maitiro eHPMC
HPMC ndeye multifunctional polymer zvinhu zvakagadzirwa nekemikari shanduko yeyakasikwa cellulose. Muchimiro chayo chemakemikari, hydroxypropyl (-CH₂CH(OH)CH₃) uye methyl (-CH₃) mapoka anotsiva chikamu chemapoka ehydroxyl (-OH) pane cellulose molecular chain, zvichiita kuti HPMC ive yakanaka solubility yemvura uye kukora zvivakwa.
Solubility: HPMC inonyungudika zviri nyore mumvura inotonhora kuti iite yakajeka kune milky colloidal mhinduro. Inonyungudika zvishoma nezvishoma mumvura inopisa, iyo inobatsira kuti igoverwe zvakaenzana mukuvaka dhaka.
Kuchengetwa kwemvura: Iyo polymer cheni yeHPMC inogona kunyatso kunwisa mvura uye kugadzira yakakwira-viscosity colloidal mhinduro, nekudaro ichidzikisa kurasikirwa kwemvura.
Kugadzikana: HPMC ine yakanakisa kugadzikana kwemakemikari uye kushivirira kune tembiricha uye pH kukosha, izvo zvinoita kuti ishande zvakatsiga pasi pemamiriro akasiyana ekuvaka.
2. Basa reHPMC mukuvaka dhaka
Wedzera kuchengetwa kwemvura: HPMC inogona kuvandudza zvakanyanya simba rekuchengetedza mvura yekuvaka dhaka, kunyanya nekutora mvura yemahara mudhaka uye kuderedza kubuda kwemvura uye kubuda.
Kuvandudza kushanda: Sezvo HPMC ichigona kuumba yakanaka yakapararira network mudhaka, inogona kuvandudza mapurasitiki uye kushanda kwedhaka, zvichiita kuti kuvaka kuve nyore.
Wedzera nguva yakavhurika: Kugona kweHPMC kuchengetedza hunyoro kunobvumira dhaka kuchengetedza kuwirirana kwakakodzera kuvakwa kwenguva yakareba, nekudaro ichiwedzera nguva yakavhurika yedhaka.
3. Mechanism yeHPMC yekuvandudza kuchengetwa kwemvura
Iyo nzira yeHPMC yekuvandudza kuchengetwa kwemvura yedhaka inonyanya kusanganisira zvinotevera zvinhu:
Adsorption: Iwo hydroxypropyl uye methyl mapoka paHPMC mamorekuru cheni anosanganisa nemamorekuru emvura kuburikidza nehydrogen bond uye van der Waals anomanikidza kuumba yakagadzikana hydration layer. HPMC inogona kutora huwandu hwemvura kuti iite yakagadzikana gel mamiriro. Iyi gel mamiriro anogona kuchengetedza hunyoro hwepamusoro mudhaka uye kudzivirira kukurumidza kubuda kwemvura.
Viscoelastic properties: HPMC inonyunguduka mumvura kuti iite high viscosity colloidal solution, iyo inogona kuwedzera zvakanyanya viscosity uye rheology yedhaka. Iyo yakakwirira viscosity fluid chikamu inobatsira kuderedza kufamba kwemvura, kuchengetedza yunifomu yekugoverwa kwemvura mudhaka, uye kuderedza kupatsanurwa kwemvura (kureva, kuyerera kwemvura uye kunaya).
Structural network formation: HPMC inogona kuumba muchinjika-yakabatana network chimiro mune aqueous mhinduro, iyo inobatsira kukiya mumvura uye kumisa kufamba kwayo mudhaka, nekudaro ichivandudza kuchengetwa kwemvura kwedhaka. Iyi network yemagadzirirwo eHPMC inobvumira dhaka kuti rirambe rakanyorova panguva yekuomesa, kudzivirira matambudziko ekutsemuka anokonzerwa nekurasikirwa nemvura isina kuenzana.
Colloidal barrier effect: Iyo colloidal barrier inoumbwa neHPMC mudhaka inogona kudzivirira mvura kuti isapararire kunze. Ichi chipingamupinyi chinoita kuti zviome zvakanyanya kuti mvura ibude kubva mudhaka, nekudaro ichiwedzera kuchengetwa kwemvura kwedhaka.
4. Kushanda kwekushandisa kweHPMC kuchengetedza mvura
Mumashandisirwo anoshanda, kuchengetwa kwemvura kweHPMC kune mhedzisiro yakakura pakuita kwedhaka, kusanganisira kuvandudza kushanda kwedhaka, kuderedza njodzi yekupwanyika kweshrinkage, nekuvandudza simba rebhondi. Izvi mhedzisiro yekushandisa inokurukurwa zvakadzama pazasi.
Kuvandudza kushanda: Iyo colloidal mhinduro yakaumbwa neHPMC mudhaka inogona kudzoreredza zvimedu mudhaka, kuvandudza kushanda kwedhaka, uye kuita kuti basa rekuvaka rive nyore.
Deredza shrinkage uye kuputika: Sezvo HPMC ichigona kuchengetedza hunyoro mudhaka, inoderedza kurasikirwa kwehunyoro panguva yekuomeswa, izvo zvakakosha kudzivirira shrinkage uye kuputika kwedhaka. Doka rinoramba rakanyorova panguva yekuomeswa kwemaitiro rine kushomeka kwekunetseka, nekudaro ichideredza mukana wekutsemuka.
Kuvandudza simba rechisungo: Hunyoro hwakagovaniswa mudhaka hunobatsira kuvandudza kushanda kweiyo hydration reaction yedhaka, kuve nechokwadi chekuti masimende akazara hydrated, uye pakupedzisira anoumba chisungo chakasimba. HPMC inogona kupa nharaunda yakareba yakanyorova, ichiita kuti simende hydration iwedzere kuzara, nekudaro ichiwedzera kusimba kwechisungo chedhaka.
5. Zvinhu zvinokanganisa HPMC pakuvaka dhaka
Iyo yekuchengeta mvura mhedzisiro yeHPMC inokanganiswa nezvinhu zvakawanda, zvinosanganisira huremu hwayo hwemamorekuru, dhigirii rekutsiva, huwandu hwekuwedzera uye dhaka reshiyo.
Molecular uremu: Kazhinji kutaura, iyo yakakura iyo molecular huremu hweHPMC, iyo inonyanya kukosha iyo yekuchengeta mvura maitiro. Zvisinei, huremu hwakakura kwazvo hunogonawo kukonzera kudzikira kwekunyungudika, saka mumashandisirwo anoshanda, zvinodikanwa kuti usarudze huremu hwakakodzera hwemamorekuru zvichienderana nezvinodiwa chaizvo.
Dhigirii rekutsiva: Iyo dhigirii yekutsiva yehydroxypropyl uye methyl muHPMC ine simba guru pakuita kwayo. Dhigirii yakakodzera yekutsiva inogona kupa kuchengetwa kwemvura kwakanaka uye kunyungudika, asi yakawandisa kana yakaderera kutsiva inogona kukanganisa kushanda kwayo.
Kuwedzera huwandu: Huwandu hwekuwedzera hweHPMC hunokanganisa zvakananga kuchengetwa kwemvura kwedhaka. Kazhinji, huwandu hwekuwedzera huri pakati pe0.1% ne0.3%. Kuwedzera kwakawanda kuchawedzera mutengo uye kunogona kukanganisa zvimwe zvivakwa zvedhaka.
Mortar ratio: Huyero hwezvimwe zvikamu mudhaka, senge simende, jecha uye filler, zvinokanganisawo kuchengetedza kwemvura kweHPMC. Inonzwisisika ratio inogona kutamba zvirinani basa reHPMC.
HPMC inoita basa rakakosha mukuchengetedza mvura mukuvaka dhaka kuburikidza neyakasiyana makemikari chimiro uye zvemuviri zvimiro. Maitiro ayo makuru anosanganisira adsorbing mvura kuti iite yakagadzikana hydration layer, kuwedzera dhaka viscosity, kugadzira network chimiro uye colloidal chipingamupinyi, etc. Muzvishandiso zvinoshanda, HPMC haingogadzirisi kushanda uye kusungirirwa kwesimba redhaka, asiwo kunoderedza njodzi kupera uye kuputika. Mune ramangwana, nekuvandudzwa kwesainzi yemidziyo, kushandiswa kweHPMC muzvigadzirwa zvekuvaka kuchave kwakawedzera uye kwakasiyana, uye kuenderera mberi nekupa mhinduro dzemhando yepamusoro kuindasitiri yekuvaka.
Nguva yekutumira: Jun-26-2024