Focus on Cellulose ethers

Hydroxypropyl Methylcellulose (HPMC) inogadzirwa sei?

Hydroxypropyl methylcellulose (HPMC) is semi-synthetic mvura-soluble polymer inowanzoshandiswa mumishonga, kuvaka uye maindasitiri ezvekudya, pakati pezvimwe. Inotorwa kubva ku cellulose, yakasikwa polymer inowanikwa mumiti yesero madziro. Iyi inotevera ongororo yakajairika yeiyo HPMC yekugadzira maitiro:

Kunobva cellulose:

Iyo huru yezvigadzirwa zveHPMC kugadzirwa ndeye cellulose, iyo inogona kutorwa kubva pahuni pulp kana machira ekotoni. Huni pulp inzvimbo yakajairika nekuti yakawanda uye inodhura-inoshanda.

Alkali kurapwa:

Cellulose inobatwa nealkali (kazhinji sodium hydroxide) kubvisa tsvina uye hemicellulose. Iyi nzira, inonzi mercerization, inogadzira cellulose yakacheneswa.

Etherification:

Iyo yakacheneswa cellulose inozoiswa pasi pe etherification, kemikari inoitwa inopinza mapoka eether mu cellulose musana. Kune HPMC, ese ari maviri hydroxypropyl uye methyl mapoka anounzwa pane cellulose morekuru.

Hydroxypropylation:

Propylene oxide inoshandiswa kuunza mapoka ehydroxypropyl mu cellulose. Iyi nhanho inosanganisira kuita kwepropylene oxide uye cellulose pamberi peiyo catalyst.

Methylation:

Mapoka eMethyl anounzwa muhydroxypropylated cellulose achishandisa methyl chloride kana dimethyl sulfate. Danho iri rinonzi methylation.

Neutralizing uye kuwacha:

Mushure mekuita kwe etherification, chigadzirwa hachina kusimba kubvisa chero hwaro hwasara. Iyo HPMC inoguma inogezwa kuti ibvise-zvigadzirwa uye makemikari asina kubatwa.

kuomesa:

Nhanho yekupedzisira inosanganisira kuomesa HPMC kubvisa mvura yakawandisa uye kuwana chigadzirwa chaunoda muhupfu kana granular fomu.

Izvo zvakakosha kuti uzive kuti iwo chaiwo ruzivo rwemaitiro ekugadzira anogona kusiyana pakati pevagadziri, uye vanogona kushandisa akasiyana mamiriro, catalysts, uye reagents kuti vawane kuita kwaunoda kweHPMC. Pamusoro pezvo, matanho ekudzora emhando anoitwa mukati memaitiro ekugadzira kuti ave nechokwadi chekuenderana uye kuchena kwechigadzirwa chekupedzisira.


Nguva yekutumira: Nov-24-2023
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