Hydroxypropyl methylcellulose (HPMC) yakakosha semi-synthetic cellulose ether komboni, iyo inoshandiswa zvakanyanya mumishonga, zvekuvaka, chikafu, machira uye mamwe maindasitiri. HPMC ine yakanaka thickening, emulsification, firimu-kuumba, moisturizing, kudzikamisa uye zvimwe zvinhu, saka ine inokosha chikumbiro kukosha mundima dzakawanda. Iwo makuru ezvigadzirwa zvekugadzira HPMC zvinosanganisira cellulose, sodium hydroxide, propylene oxide, methyl chloride nemvura.
1. Cellulose
Cellulose ndiyo yakakosha zvinhu zveHPMC, kazhinji inotorwa kubva kune yakasikwa chirimwa fibers sedonje nehuni. Cellulose ndiyo yakanyanya kuwanda yakasikwa organic polymer panyika. Chimiro chayo chemolecular is a long-chain polysaccharide inoumbwa neglucose units yakabatanidzwa ne β-1,4-glycosidic bonds. Cellulose pachayo haina kunyungudika mumvura uye haina yakanaka kemikari reactivity. Naizvozvo, nhevedzano yemakemikari ekugadzirisa maitiro anodiwa kuti awedzere kunyungudika uye kushanda kwayo kugadzirira akasiyana cellulose ether zvigadzirwa.
2. Sodium hydroxide (NaOH)
Sodium hydroxide, inozivikanwawo se caustic soda, isimbi yakasimba yealkaline iyo inoita basa rakakosha sealkalizer mukugadzirwa kweHPMC. Muchikamu chekutanga chekugadzirwa, cellulose inopindirana nesodium hydroxide solution kumisa mapoka ehydroxyl pane cellulose molecular chain, nokudaro ichipa maitirwo enzvimbo kune inotevera etherification reaction. Iyi nhanho inonziwo "alkalization reaction". Iyo alkalized cellulose inosangana nekuchinja kwechimiro, zvichiita kuti zvive nyore kuita neanotevera kemikari reagents (senge propylene oxide uye methyl chloride).
3. Propylene oxide (C3H6O)
Propylene oxide imwe yeakakosha etherifying agents mukugadzirwa kweHPMC, inonyanya kushandiswa kushandura mapoka ehydroxyl mu cellulose kuita mapoka ehydroxypropyl. Kunyanya, iyo alkalized cellulose inopindirana nepropylene oxide pasi peimwe tembiricha uye kudzvanywa mamiriro, uye anoshanda epoxy mapoka mupropylene oxide akabatanidzwa kune molecular chain ye cellulose kuburikidza nemhete-yekuvhura yekuwedzera kuita kuti igadzire hydroxypropyl substituent. Iyi nzira inopa HPMC yakanaka kunyungudika kwemvura uye kugona kukora.
4. Methyl chloride (CH3Cl)
Methyl chloride imwe yakakosha etherifying agent inoshandiswa kushandura mapoka ehydroxyl e cellulose kuita methoxyl mapoka. Methyl chloride inopindirana nemapoka e-hydroxyl pa cellulose molecular chain kuburikidza ne nucleophilic substitution reaction kuti ibudise methyl cellulose. Kuburikidza neiyi methylation reaction, HPMC inowana yakanaka hydrophobicity, kunyanya kuratidza yakanakisa solubility mune mamwe organic solvents. Uye zvakare, kuunzwa kwemapoka emethoxy kunowedzera kuvandudza iyo firimu-yekugadzira pfuma uye kugadzikana kwemakemikari eHPMC.
5. Mvura
Mvura, seyekunyungudutsa uye yekupindura svikiro, inomhanya kuburikidza neyese HPMC kugadzirwa maitiro. Mune alkalization uye etherification maitiro, mvura haingobatsiri kunyungudutsa sodium hydroxide uye kugadzirisa iyo hydration mamiriro e cellulose, asi zvakare inotora chikamu mukugadzirisa kwekuita kupisa kuve nechokwadi chekudzora tembiricha mukati mekuita maitiro. Kuchena kwemvura kune simba rakakosha pamhando yeHPMC, uye yakakwirira-kuchena yakasvibiswa mvura kana mvura yakasvibiswa inowanzodiwa.
6. Organic solvents
Mukugadzirwa kweHPMC, mamwe matanho angangodawo kushandiswa kwemamwe organic solvents, senge methanol kana ethanol. Izvi zvinonyungudutsa dzimwe nguva zvinoshandiswa kugadzirisa viscosity yemaitiro ekugadzirisa, kuderedza kuumbwa kwekuita ne-zvigadzirwa, kana kukurudzira maitiro emakemikari chaiwo. Sarudzo ye organic solvent inoda kutariswa zvinoenderana nezvinodiwa zvekugadzira uye kushandiswa kwechigadzirwa chekupedzisira.
7. Zvimwe zvinhu zvekubatsira
Pamusoro pezvakanyanya pamusoro pezvigadzirwa, mune chaiyo yekugadzira maitiro, zvimwe zvekubatsira uye zvinowedzera, senge catalysts, stabilizers, nezvimwe, zvinogona kushandiswa kuvandudza kuita kwekuita, kudzora chiyero chekuita kana kuvandudza chimiro chemuviri nemakemikari. yechigadzirwa chekupedzisira.
8. Matanho makuru ekugadzira maitiro
Iwo makuru maitiro matanho ekugadzira HPMC anogona kukamurwa kuita zvikamu zvitatu: alkalization, etherification uye neutralization kurapwa. Chekutanga, cellulose inopindirana ne sodium hydroxide ku alkalize kuita alkali cellulose. Zvadaro, etherification inoitika mukuita kwealkali cellulose ine propylene oxide uye methyl chloride kuumba hydroxypropyl uye methoxy inotsiva cellulose ethers. Chekupedzisira, kuburikidza ne neutralization kurapwa, kugeza, kuomesa uye mamwe maitiro, HPMC zvigadzirwa zvine chaiyo solubility, viscosity uye humwe hunhu hunowanikwa.
9. Mhedzisiro yemhando yezvinhu zvakasvibiswa pakuita kweHPMC zvigadzirwa
Yakasiyana mbishi zvitubu uye kuchena zvine chekuita kwakakura pamhando uye kuita kweiyo yekupedzisira HPMC. Semuyenzaniso, kuchena uye molecular uremu kugoverwa kweselulosi mbishi zvinhu zvinokanganisa viscosity uye solubility yeHPMC; iyo dosage uye maitiro emamiriro epropylene oxide uye methyl chloride inotarisisa dhigirii rehydroxypropyl uye methoxy substitution, zvichizokanganisa kukora uye firimu-kugadzira zvinhu zvechigadzirwa. Naizvozvo, kusarudzwa uye kudzora kwemhando yezvigadzirwa zvakakosha panguva yekugadzira.
Izvo zvakakosha zvekushandisa zvehydroxypropyl methylcellulose (HPMC) zvinosanganisira cellulose, sodium hydroxide, propylene oxide, methyl chloride uye mvura. Kuburikidza nenhevedzano yemaitiro akaomarara emakemikari, izvi mbishi zvinhu zvinoshandurwa kuita zvinhu zvinoshanda zvine kukosha kwekushandisa kwakakura. Iyo yekushandiswa kwemhando yeHPMC inovhara minda yakawanda senge mushonga, zvekuvaka, uye chikafu. Hunhu hwayo hwakanaka hwemuviri nemakemikari hunoita kuti ive yakakosha mumaindasitiri mazhinji.
Nguva yekutumira: Sep-30-2024