Hydroxypropylmethylcellulose (HPMC) ikomboni yave chinhu chakanyanya mbishi mumaindasitiri mazhinji nekuda kwemabasa ayo akawanda. Inowanzoshandiswa sechikafu chekuwedzera, mukobvu muzvizoro, uye kunyange mushonga wemishonga mumishonga yakawanda. Chinhu chakasarudzika cheHPMC maitiro ayo ethixotropic, ayo anoibvumira kushandura viscosity uye kuyerera zvivakwa pasi pemamwe mamiriro. Uye zvakare, ese ari maviri akakwira-viscosity uye yakaderera-viscosity HPMC ine ichi chivakwa, ichiratidza thixotropy kunyangwe pazasi tembiricha yegel.
Thixotropy inoitika muHPMC apo mhinduro inova shear-kuonda kana kudzvinyirirwa kunoshandiswa kana kukurudzirwa, zvichiita kuti kuderera kwe viscosity. Hunhu uhu hunogonawo kudzoserwa shure; apo kushungurudzika kunobviswa uye mhinduro inosara kuti igare, viscosity inodzokera zvishoma nezvishoma kune yakakwirira. Ichi chakasarudzika chivakwa chinoita kuti HPMC ive chinhu chakakosha mumaindasitiri mazhinji sezvo ichibvumira kushandiswa kwakapfava uye nyore kugadzirisa.
Senge nonionic hydrocolloid, HPMC inozvimba mumvura kuita gel. Iyo dhigirii yekuzvimba uye gelling zvinoenderana nehuremu hwemamorekuru uye kusungirirwa kwepolymer, iyo pH uye tembiricha yemhinduro. High viscosity HPMC kazhinji ine huremu hwemamorekuru uye inogadzira gel yakakwira viscosity, nepo low viscosity HPMC ine huremu hwakaderera uye inogadzira gel shoma. Nekudaro, kunyangwe iyi misiyano mukuita, ese ari maviri marudzi eHPMC anoratidza thixotropy nekuda kwekuchinja kwemaitiro kunoitika padanho remamorekuru.
Iyo thixotropic maitiro eHPMC mhedzisiro yekurongeka kwemaketani epolymer nekuda kwekunetseka kwekugera. Kana shear stress ichiiswa kuHPMC, macheni epolymer anonangana negwara rekushushikana kwakaiswa, zvichikonzera kuparadzwa kwematatu-dimensional network chimiro chaivepo pasina kushushikana. Kuvhiringidzwa kwetiweki kunoguma nekuderera kwemhinduro viscosity. Kana kushushikana kwabviswa, cheni dzepolymer dzinoronga patsva pamwe nekwavo yekutanga, kuvakazve network uye kudzoreredza viscosity.
HPMC inoratidzawo thixotropy pazasi tembiricha yegelling. Tembiricha yegel ndiyo tembiricha apo polymer cheni inoyambuka-inobatana kuita matatu-dimensional network, ichigadzira gel. Izvo zvinoenderana nekutarisa, molecular uremu uye pH yemhinduro yepolymer. Iyo gel inoguma ine viscosity yakakwirira uye haishanduki nokukurumidza pasi pekumanikidzwa. Nekudaro, pazasi petembiricha yegelation, iyo HPMC mhinduro yakaramba iri mvura, asi ichiri kuratidza thixotropic maitiro nekuda kwekuvapo kwechikamu chakaumbwa network chimiro. Iyo network inoumbwa nezvikamu izvi inoputsika pasi pekumanikidzwa, zvichikonzera kuderera kwe viscosity. Maitiro aya anobatsira mune akawanda maapplication apo mhinduro dzinoda kuyerera zviri nyore kana dzamutswa.
HPMC ikemikari inosiyana-siyana ine akati wandei akasiyana zvivakwa, imwe yacho hunhu hwayo hwethixotropic. Ose ari maviri akakwira-viscosity uye yakaderera-viscosity HPMCs ane ichi chivakwa, achiratidza thixotropy kunyangwe pazasi tembiricha yegel. Hunhu uhu hunoita kuti HPMC ive chinhu chakakosha mumaindasitiri mazhinji anoda mhinduro dzinobata kuyerera kuri nyore kuti ive nechokwadi chekushandisa. Pasinei nekusiyana kwezvivakwa pakati pe-high-viscosity uye yakaderera-viscosity HPMCs, maitiro avo ethixotropic anoitika nekuda kwekurongeka uye kukanganisa kwechikamu chakaumbwa network chimiro. Nekuda kwehunhu hwayo hwakasiyana, vaongorori vari kugara vachiongorora akasiyana maapplication eHPMC, vachitarisira kugadzira zvigadzirwa zvitsva uye nekupa mhinduro dziri nani kune vatengi pasi rese.
Nguva yekutumira: Aug-23-2023